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Read From Live Camera - ASP.NET C#

BarCode Reader SDK sample in ASP.NET C# demonstrating ‘Read From Live Camera’

!!!ReadmeFIRST!!!.txt
Readme for live web cam barcode scanning ASP.NET demo 

Supports all browsers by using 2 modes: 

(required mode is automatically detected by the javascript)
- HTML5 based web camera capture (supported by Google Chrome, Firefox, Safari, Safari on iOS browsers)
- Flash based web camera capture (supported by Internet Explorer 9+ and any browser with flash support)

IMPORTANT about HTML5 webcamera support (Chrome, Firefox, Safari on desktop and iOS): it is required to run your website (even test website) via SSL connection. Otherwise, web camera won't initialize at all as it requies SSL connection. 

Visual Studio 2008/2010 or higher is required for this sample to run!

1) Install evaluation copy of BarCode Reader SDK from www.bytescout.com
2) in Visual Studio use File - Open - Web-Site.. and open the folder with this sample
3) Add a reference to ByteScout BarCode Reader dll using the menu: Website - Add Reference (find Bytescout Barcode Reader SDK on .NET tab, select and click OK to add a reference)
4) Right-click on "Default.aspx" file and select "Set As Start Page"
5) Run the project in debug mode
6) Visual Studio will run your project in Internet Explorer or another browser
If it run Internet Explorer then better copy the link from the IE and copy-and-paste to another browser with HTML5 web cam support like Google Chrome, Firefox or Safari
7) When browser asks for permission to access web-cam click "Allow" to allow access to web cam 
8) click "START BARCODE SCAN.." button so the page will start automatically to grab frames from video and sending it to server-side code to read barcodes using Barcode Reader SDK
9) IMPORTANT: barcode should be in focus. Some webcams are not focusing on small barcodes, you may need to adjust the focus on your webcam so it will work OK with small images like barcodes

10) Click Stop to stop barcode scanning
Select barcode type to scan if need to scan a particular barcode type (by default scans for all known types)


TESTING:
- we recommend to use the Conveyor plugin to test your web app from local net or public url: https://marketplace.visualstudio.com/items?itemName=vs-publisher-1448185.ConveyorbyKeyoti

Default.aspx
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1. Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
    <title></title>
    <script src="https://ajax.microsoft.com/ajax/jquery/jquery-1.4.2.js" type="text/javascript"></script>  
    <script type="text/javascript" src="webcam.js"></script>
      <!-- this javascript plugin uses the webcam.swf file to capture image and send the image to server for further processing -->
    <script type="text/javascript">
        var canvas, context, timer;
        var constraints = window.constraints = {
            audio: false,
            video: { facingMode: "environment" } // change to "user" for front camera, see https://developer.mozilla.org/en-US/docs/Web/API/MediaTrackConstraints/facingMode
        };
        //  (HTML5 based camera only) this portion of code will be used when browser supports navigator.getUserMedia  *********     */
        window.addEventListener("DOMContentLoaded", function () {
            canvas = document.getElementById("canvasU"),
            context = canvas.getContext("2d"),
            video = document.getElementById("video"),
            videoObj = { "video": true },
            errBack = function (error) {
                console.log("Video capture error: ", error.code);
            };

            // check if we can use HTML5 based camera (through mediaDevices.getUserMedia() function)
            if (navigator.mediaDevices.getUserMedia) { // Standard browser
                // display HTML5 camera
                document.getElementById("userMedia").style.display = '';
                // adding click event to take photo from webcam
                document.getElementById("snap").addEventListener("click", function () {
                    context.drawImage(video, 0, 0, 640, 480);
                });

                navigator.mediaDevices
                    .getUserMedia(constraints)
                    .then(handleSuccess)
                    .catch(handleError);
            }
            // check if we can use HTML5 based camera (through .getUserMedia() function in Webkit based browser)
            else if (navigator.webkitGetUserMedia) { // WebKit-prefixed for Google Chrome
                // display HTML5 camera
                document.getElementById("userMedia").style.display = '';
                // adding click event to take photo from webcam
                document.getElementById("snap").addEventListener("click", function () {
                    context.drawImage(video, 0, 0, 640, 480);
                });
                navigator.webkitGetUserMedia(videoObj, function (stream) {
                    video.src = window.webkitURL.createObjectURL(stream);
                    video.play();
                }, errBack);
            }
            // check if we can use HTML5 based camera (through .getUserMedia() function in Firefox based browser)
            else if (navigator.mozGetUserMedia) { // moz-prefixed for Firefox 
                // display HTML5 camera
                document.getElementById("userMedia").style.display = '';
                // adding click event to take photo from webcam
                document.getElementById("snap").addEventListener("click", function () {
                    context.drawImage(video, 0, 0, 640, 480);
                });
                navigator.mozGetUserMedia(videoObj, function (stream) {
                    video.mozSrcObject = window.webkitURL.createObjectURL(stream);
                    video.play();
                }, errBack);
            }
            else
            // if we can not use any of HTML5 based camera ways then we use Flash based camera
            {
                // display Flash camera
                document.getElementById("flashDiv").style.display = '';
                document.getElementById("flashOut").innerHTML = (webcam.get_html(640, 480));
            }

        }, false);

        // (all type of camera) set the default selection of barcode type
        var selection = "All barcodes (slow)";

        // (all type of camera) gets the selection text of "barcode type to scan" combobox
        function selectType(type) {
            selection = type.options[type.selectedIndex].text;
        }

        function handleSuccess(stream) {
            var video = document.querySelector('video');
            var videoTracks = stream.getVideoTracks();
            console.log('Got stream with constraints:', constraints);
            console.log(`Using video device: ${videoTracks[0].label}`);
            window.stream = stream; // make variable available to browser console
            video.srcObject = stream;
        }

        function handleError(error) {
            if (error.name === 'ConstraintNotSatisfiedError') {
                var v = constraints.video;
                errorMsg(`The resolution ${v.width.exact}x${v.height.exact} px is not supported by your device.`);
            } else if (error.name === 'PermissionDeniedError') {
                errorMsg('Permissions have not been granted to use your camera and ' +
                    'microphone, you need to allow the page access to your devices in ' +
                    'order for the demo to work.');
            }
            errorMsg(`getUserMedia error: ${error.name}`, error);
        }

        function errorMsg(msg, error) {
            var errorElement = document.querySelector('#errorMsg');
            errorElement.innerHTML += `<p>${msg}</p>`;
            if (typeof error !== 'undefined') {
                console.error(error);
            }
        }

        // (HTML5 based camera only)
        // uploads the image to the server 
        function UploadToCloud() {        
            document.getElementById('report').innerHTML = "scanning the current frame......";
            context.drawImage(video, 0, 0, 640, 480);
            $("#upload").attr('disabled', 'disabled');
            $("#upload").attr("value", "Uploading...");
            var img = canvas.toDataURL('image/jpeg', 0.9).split(',')[1];
            // send AJAX request to the server with image data 
            $.ajax({
                url: "HTML5Camera.aspx/Upload",
                type: "POST",
                data: "{ 'image': '" + img + "' , 'type': '" + selection + "'}",
                contentType: "application/json; charset=utf-8",
                dataType: "json",
                // on success output the result returned by the server side (See HTML5Camera.aspx)
                success: function (data, status) {
                    $("#upload").removeAttr('disabled');
                    $("#upload").attr("value", "Upload");
                    if (data.d.length != 0) {
                        var htmlSelect = document.getElementById('OutListBoxHTML5');
			    
			//var selectBoxOption = document.createElement("option");
	                //selectBoxOption.text = data.d;
        	        //selectBoxOption.id = "child";
                	//htmlSelect.insertBefore(selectBoxOption, htmlSelect.childNodes[0]);
	                htmlSelect.value = data.d + "\r\n" + htmlSelect.value;			    			    
                    }
                },
                // on error just show the message that no barcodes were found
                error: function (data) {
                    document.getElementById('report').innerHTML = "no barcode found, scanning.....";
                    $("#upload").removeAttr('disabled');
                    $("#upload").attr("value", "Upload");
                },
                async: false
            });
            timer = setTimeout(UploadToCloud, 3000);  // will capture new image to detect barcode after 3000 mili second
        }

        // (flash based camera only) stop the capturing 
        function stopCall() {
            document.getElementById('report').innerHTML = "STOPPED Scanning."
            clearTimeout(timer);
        }

        // (flash based camera only) sets the handler for callback completition to output the result
        Webcam.on('onComplete', 'my_completion_handler');
        
        // (flash based camera only) this function will start flash to capture image and send the image to the server for further processing (for IE)
        function take_snapshot() {
            // set api to be called by flash camera
            webcam.set_api_url('FlashCamera.aspx?type=' + selection);
            webcam.set_quality(100);
            // enable the shutter sound
            webcam.set_shutter_sound(true);
            document.getElementById('upload_results').innerHTML = '<h4>Scanning...</h4>';
            // capture image from the webcam
            webcam.snap();
            // set timout to capter new image (interval between captures)
            timer = setTimeout(take_snapshot, 3000);
        }

        // (flash based camera only) this one will work after recieving barcode from server
        // this function writes the output result back to the front page (from server side)
        function my_completion_handler(msg) {
            var str = msg;
            // encode into html compatible string
            var result = str.match(/<d>(.*?)<\/d>/g).map(function (val) {
                return val.replace(/<\/?d>/g, '');
            });
            // add new result into the listbox 
            var htmlSelect = document.getElementById('OutListBoxFlash');
            //var selectBoxOption = document.createElement("option");
            //selectBoxOption.text = result;
            //selectBoxOption.id = "child";
            //htmlSelect.insertBefore(selectBoxOption, htmlSelect.childNodes[0]);		
	    htmlSelect.value = result + "\r\n" + htmlSelect.value;	
		
            // reset webcam and flash to capture new image. this reset process flickers a little
            webcam.reset();         
        }

        // (flash based camera only) stop the scan and set the message on the page
        function stopScanning() {
            document.getElementById('upload_results').innerHTML = "STOPPED Scanning."
            clearTimeout(timer);
        }
    </script>
    <style>
    span
    {
        font-size:20px;
    }
    </style>
</head>
<body>
    <form id="form1" runat="server">
    <!-- HTML5 camera based capturing section -->
    <!-- this div block will be shown when browser supports get user media-->
        <div id="userMedia"  style="display:none; height: 575px; width: 1182px">  
        <table>
        <tr align="left" valign="top">
        <td valign="top" colspan="2">
        <h3 style=" color:Green; ">(HTML5 based camera) This works in Chrome, Firefox, Safari and other modern browsers with HTML5 support. If HTML5 camera is not enabled then Flash based camera should appear instead. To enable web-cam access answer ALLOW when asked if you want to give access to webcam </h3>
	<strong>IMPORTANT: html5 webcam access (Chrome, Firefox, Safari on desktop and iOS) requires SSL connection! Otherwise, web camera will not initialize at all as it requies SSL connection only. </strong>
        </td>
        </tr>
          <tr align="left" valign="top">
                <td valign="top">
                    <h2 id="choiceU"> <b>Barcode Type To Scan (to start barcode scan - click START below)</b></h2> 
                    <br />
          <select id="comboBoxBarCodeTypeHTML5" onchange="selectType(this)">
            <option value="1">All Barcodes (slow)</option>
            <option value="2">All Linear Barcodes (Code39, Code 128, EAN 13, UPCA, UPCE, etc.)</option>
            <option value="3">All 2D Barcodes (QR Code, Aztec, DataMatrix, PDF417, etc.)</option>
            <option value="4">Code 39c</option>
            <option value="5">Code 128</option>
            <option value="6">EAN 13</option>
            <option value="7">UPCA</option>
            <option value="8">GS1-128</option>
            <option value="9">GS1DataBarExpanded</option>
            <option value="10">GS1DataBarExpandedStacked </option>
            <option value="11">GS1DataBarLimited</option>
            <option value="12">GS1DataBarOmnidirectional</option>
            <option value="13">GS1DataBarStacked</option>
            <option value="14">I2of5</option>
            <option value="15">Intelligent Mail</option>
            <option value="16">Patch Code</option>
            <option value="17">PDF 417</option>
            <option value="18">QR Code</option>
            <option value="19">DataMatrix</option>
            <option value="20">Aztec</option>
            <option value="21">MaxiCode</option>
         </select>        
        <br />
        <span style=" font-size:20px; ">Output barcode values read appears below: </span>
        <br />
            <!-- decoding results appears in this listbox -->
            <textarea style="width:500px; height:100px;" size="8" id="OutListBoxHTML5"> 
            </textarea>
        <br />
            <input id="snap"  style="color:black; font-weight:bold; font-size:x-large;" type="button" onclick="UploadToCloud();" value="START READING BARCODES..." />
            <input id="pause" style="color:black;" type="button" onclick="stopCall();" value="STOP" />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <h4 id="report" >
         </td>
         <td valign="top">   
            <span>Webcam preview shows below:</span>
            <video id="video" width="640" height="480" autoplay playsinline muted></video> 
         <!-- canvas with the output -->
       <canvas id="canvasU" width="640" height="480" style="display:none" ></canvas>     
                   
         </td>
         </tr>
         </table>
    </div>

    <!-- Flash (SWF) camera based capturing section -->
    <!-- this div block will be shown when browser does not support user media so the only way is to capture with flash (swf) camera -->
         <div id="flashDiv" style=" display:none; ">  
            <table>
            <tr align="left" valign="top">
            <td colspan="2"><h3 style=" color:Green; " >(FLASH based camera) This works in Internet Explorer 9+, Chrome, Firefox and other browsers with flash support. To enable web-cam access answer ALLOW when asked if you want to give access to webcam </h3></td>
            </tr>
            <tr align="left" valign="top">
                <td valign="top">
                    <h4 id="choice"> <b>Barcode Type To Scan (to start barcode scan - click START below)</b></h4> 
                    <br />
                     <select id="comboBoxBarCodeTypeFlash" onchange="selectType(this)">
            <option value="1">All Barcodes (slow)</option>
            <option value="2">All Linear Barcodes (Code39, Code 128, EAN 13, UPCA, UPCE, etc.)</option>
            <option value="3">All 2D Barcodes (QR Code, Aztec, DataMatrix, PDF417, etc.)</option>
            <option value="4">Code 39</option>
            <option value="5">Code 128</option>
            <option value="6">EAN 13</option>
            <option value="7">UPCA</option>
            <option value="8">GS1-128</option>
            <option value="9">GS1DataBarExpanded</option>
            <option value="10">GS1DataBarExpandedStacked </option>
            <option value="11">GS1DataBarLimited</option>
            <option value="12">GS1DataBarOmnidirectional</option>
            <option value="13">GS1DataBarStacked</option>
            <option value="14">I2of5</option>
            <option value="15">Intelligent Mail</option>
            <option value="16">Patch Code</option>
            <option value="17">PDF 417</option>
            <option value="18">QR Code</option>
            <option value="19">DataMatrix</option>
            <option value="20">Aztec</option>
            <option value="21">MaxiCode</option>
   </select>
            <br />
            <span style=" font-size:20px; ">Output barcode values read appears below: </span>
        <br />

            <!-- decoding results appears in this listbox -->
          <textarea style="width:500px; height:100px;" size="8" id="OutListBoxFlash"> </textarea>
    <br />
		<input type="button"  style="color:black; font-weight:bold; font-size:x-large;" value="START READING BARCODES.." onclick="take_snapshot()"/> &nbsp;&nbsp;&nbsp;
        <br />
        <input type="button" style="color:black; font-weight:bold; font-size:x-large;" value="STOP" onclick="stopScanning()"/>
        <br />                   
    </div>
    <div id="upload_results" style="background-color:#eee;"></div>
    </td>
    <td>    
    <div id="flashOut"> </div>
    </td>
   </tr>
    </table>
            
    </form>
   
</body>
</html>

Default.aspx.cs
using System;
using System.Collections.Generic;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        /*
        IF YOU SEE TEMPORARY FOLDER ACCESS ERRORS: 

        Temporary folder access is required for web application when you use ByteScout SDK in it.
        If you are getting errors related to the access to temporary folder like "Access to the path 'C:\Windows\TEMP\... is denied" then you need to add permission for this temporary folder to make ByteScout SDK working on that machine and IIS configuration because ByteScout SDK requires access to temp folder to cache some of its data for more efficient work.

        SOLUTION:

        If your IIS Application Pool has "Load User Profile" option enabled the IIS provides access to user's temp folder. Check user's temporary folder

        If you are running Web Application under an impersonated account or IIS_IUSRS group, IIS may redirect all requests into separate temp folder like "c:\temp\".

        In this case
        - check the User or User Group your web application is running under
        - then add permissions for this User or User Group to read and write into that temp folder (c:\temp or c:\windows\temp\ folder)
        - restart your web application and try again

        */

    }
}

FlashCamera.aspx
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="FlashCamera.aspx.cs" Inherits="uploadimage" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    
    </div>
    </form>
</body>
</html>

FlashCamera.aspx.cs
using System;
using System.Collections.Generic;
using System.Web;
using System.Web.UI;
using System.IO; //For MemoryStream
using System.Web.Services; //For WebMethod attribute
using Bytescout.BarCodeReader;
using System.Web.UI.HtmlControls;
using System.Drawing;
using System.Drawing.Imaging;
using System.Threading;

public partial class uploadimage : System.Web.UI.Page
{
    /*
    IF YOU SEE TEMPORARY FOLDER ACCESS ERRORS: 

    Temporary folder access is required for web application when you use ByteScout SDK in it.
    If you are getting errors related to the access to temporary folder like "Access to the path 'C:\Windows\TEMP\... is denied" then you need to add permission for this temporary folder to make ByteScout SDK working on that machine and IIS configuration because ByteScout SDK requires access to temp folder to cache some of its data for more efficient work.

    SOLUTION:

    If your IIS Application Pool has "Load User Profile" option enabled the IIS provides access to user's temp folder. Check user's temporary folder

    If you are running Web Application under an impersonated account or IIS_IUSRS group, IIS may redirect all requests into separate temp folder like "c:\temp\".

    In this case
    - check the User or User Group your web application is running under
    - then add permissions for this User or User Group to read and write into that temp folder (c:\temp or c:\windows\temp\ folder)
    - restart your web application and try again

    */

	protected void Page_Load(object sender, EventArgs e)
    {

        try
        {
            String send = "";
            System.Drawing.Image originalimg;
            // read barcode type set 
            String type = Request.QueryString["type"].ToString();
            MemoryStream log = new MemoryStream();
            byte[] buffer = new byte[1024];
            int c;
            // read input buffer with image and saving into the "log" memory stream
            while ((c = Request.InputStream.Read(buffer, 0, buffer.Length)) > 0)
            {
                log.Write(buffer, 0, c);
            }
            // create image object
            originalimg = System.Drawing.Image.FromStream(log);
            // resample image
            originalimg = originalimg.GetThumbnailImage(640, 480, new System.Drawing.Image.GetThumbnailImageAbort(ThumbnailCallback), IntPtr.Zero);
            Bitmap bp = new Bitmap(originalimg);
            // create bytescout barcode reader object
            Reader reader = new Reader();
            // set barcode type to read
            reader.BarcodeTypesToFind = GetBarcodeTypeToFindFromCombobox(type);
            // read barcodes from image
            reader.ReadFrom(bp);
            // if there are any result then convert them into a single stream
            if (reader.FoundBarcodes != null)
            {
                foreach (FoundBarcode barcode in reader.FoundBarcodes)
                {
                    // form the output string
                    send = send + (String.Format("{0} : {1}", barcode.Type, barcode.Value));
                }
            }
            // close the memory stream
            log.Close();
            // dispose the image object
            originalimg.Dispose();
            // write output 
            Response.Write("<d>" + send + "</d>");
        }
        catch (Exception ex)
        {
            // write the exception if any
            Response.Write("<d>" + ex + "</d>");
        }
    }
    public bool ThumbnailCallback() { return false; }

    /// <summary>
    /// Get symbology filter for the SDK from the combobox selection text
    /// </summary>
    /// <param name="barType"></param>
    /// <returns></returns>
    private static BarcodeTypeSelector GetBarcodeTypeToFindFromCombobox(string barType)
    {
        string selectedItemText = barType.Trim().ToUpper();
        BarcodeTypeSelector barcodeTypeToScan = new BarcodeTypeSelector();

        if (selectedItemText.IndexOf("ALL BARCODES") > -1)
            barcodeTypeToScan.SetAll();
        else if (selectedItemText.IndexOf("ALL LINEAR BARCODES") > -1)
            barcodeTypeToScan.SetAll1D();
        else if (selectedItemText.IndexOf("ALL 2D BARCODES") > -1)
            barcodeTypeToScan.SetAll2D();
        else if (selectedItemText.IndexOf("AZTEC") > -1)
            barcodeTypeToScan.Aztec = true;
        else if (selectedItemText.IndexOf("CODABAR") > -1)
            barcodeTypeToScan.Codabar = true;
        else if (selectedItemText.IndexOf("CODE 39") > -1)
            barcodeTypeToScan.Code39 = true;
        else if (selectedItemText.IndexOf("CODE 128") > -1)
            barcodeTypeToScan.Code128 = true;
        else if (selectedItemText.IndexOf("DATAMATRIX") > -1)
            barcodeTypeToScan.DataMatrix = true;
        else if (selectedItemText.IndexOf("EAN 13") > -1)
            barcodeTypeToScan.EAN13 = true;
        else if (selectedItemText.IndexOf("GS1-128") > -1)
            barcodeTypeToScan.GS1 = true;
        else if (selectedItemText.IndexOf("GS1DATABAREXPANDED") > -1)
            barcodeTypeToScan.GS1DataBarExpanded = true;
        else if (selectedItemText.IndexOf("GS1DATABAREXPANDEDSTACKED") > -1)
            barcodeTypeToScan.GS1DataBarExpandedStacked = true;
        else if (selectedItemText.IndexOf("GS1DATABARLIMITED") > -1)
            barcodeTypeToScan.GS1DataBarLimited = true;
        else if (selectedItemText.IndexOf("GS1DATABAROMNIDIRECTIONAL") > -1)
            barcodeTypeToScan.GS1DataBarOmnidirectional = true;
        else if (selectedItemText.IndexOf("GS1DATABARSTACKED") > -1)
            barcodeTypeToScan.GS1DataBarStacked = true;
        else if (selectedItemText.IndexOf("I2OF5") > -1)
            barcodeTypeToScan.Interleaved2of5 = true;
        else if (selectedItemText.IndexOf("INTELLIGENT MAIL") > -1)
            barcodeTypeToScan.IntelligentMail = true;
        else if (selectedItemText.IndexOf("PATCH") > -1)
            barcodeTypeToScan.PatchCode = true;
        else if (selectedItemText.IndexOf("PDF 417") > -1)
            barcodeTypeToScan.PDF417 = true;
        else if (selectedItemText.IndexOf("QR CODE") > -1)
            barcodeTypeToScan.QRCode = true;
        else if (selectedItemText.IndexOf("UPCA") > -1)
            barcodeTypeToScan.UPCA = true;
        else if (selectedItemText.IndexOf("UPCE") > -1)
            barcodeTypeToScan.UPCE = true;
        else if (selectedItemText.IndexOf("MAXICODE") > -1)
            barcodeTypeToScan.MaxiCode = true;

        return barcodeTypeToScan;
    }
}

HTML5Camera.aspx
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="HTML5Camera.aspx.cs" Inherits="Camera" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    
    </div>
    </form>
</body>
</html>

HTML5Camera.aspx.cs
using System;
using System.Collections.Generic;
using System.Web;
using System.Web.UI;
using System.IO; //For MemoryStream
using System.Web.Services; //For WebMethod attribute
using Bytescout.BarCodeReader;
using System.Web.UI.HtmlControls;
using System.Drawing;
using System.Drawing.Imaging;
using System.Threading;
using System.Text;


public partial class Camera : System.Web.UI.Page
{
    /*
    IF YOU SEE TEMPORARY FOLDER ACCESS ERRORS: 

    Temporary folder access is required for web application when you use ByteScout SDK in it.
    If you are getting errors related to the access to temporary folder like "Access to the path 'C:\Windows\TEMP\... is denied" then you need to add permission for this temporary folder to make ByteScout SDK working on that machine and IIS configuration because ByteScout SDK requires access to temp folder to cache some of its data for more efficient work.

    SOLUTION:

    If your IIS Application Pool has "Load User Profile" option enabled the IIS provides access to user's temp folder. Check user's temporary folder

    If you are running Web Application under an impersonated account or IIS_IUSRS group, IIS may redirect all requests into separate temp folder like "c:\temp\".

    In this case
    - check the User or User Group your web application is running under
    - then add permissions for this User or User Group to read and write into that temp folder (c:\temp or c:\windows\temp\ folder)
    - restart your web application and try again

    */

    protected void Page_Load(object sender, EventArgs e)
    {
    }

    /// <summary>
    /// Takes the base64 encoded image from the browser
    /// and tries to read barodes from it
    /// </summary>
    /// <param name="image"></param>
    /// <param name="type"></param>
    /// <returns></returns>
    [WebMethod]
    public static string Upload(string image, string type)
    {
        try
        {
            StringBuilder send = new StringBuilder();

            // lock by send variable 
            lock (send)
            {            
                // Convert base64 string from the client side into byte array
                byte[] bitmapArrayOfBytes = Convert.FromBase64String(image);
                // Create Bytescout.BarCodeReader.Reader object
                Reader reader = new Reader();
                // Get the barcode type from user's selection in the combobox
                reader.BarcodeTypesToFind = GetBarcodeTypeToFindFromCombobox(type);
                // Read barcodes from image bytes
                reader.ReadFromMemory(bitmapArrayOfBytes);
                // Check whether the barcode is decoded
                if (reader.FoundBarcodes != null)
                {
                    // Add each decoded barcode into the string 
                    foreach (FoundBarcode barcode in reader.FoundBarcodes)
                    {
                        // Add barcodes as text into the output string
                        send.AppendLine(String.Format("{0} : {1}", barcode.Type, barcode.Value));
                    }
                }

                // Return the output string as JSON
				return send.ToString();
            }
        }
        catch (Exception ex)
        {
            // return the exception instead
            return (ex.Message + "\r\n" + ex.StackTrace);
        }
    }

    /// <summary>
    /// Get symbology filter for the SDK from the combobox selection text
    /// </summary>
    /// <param name="barType"></param>
    /// <returns></returns>
    private static BarcodeTypeSelector GetBarcodeTypeToFindFromCombobox(string barType)
    {
        string selectedItemText = barType.Trim().ToUpper();
        BarcodeTypeSelector barcodeTypeToScan = new BarcodeTypeSelector();

        if (selectedItemText.IndexOf("ALL BARCODES") > -1)
            barcodeTypeToScan.SetAll();
        else if (selectedItemText.IndexOf("ALL LINEAR BARCODES") > -1)
            barcodeTypeToScan.SetAll1D();
        else if (selectedItemText.IndexOf("ALL 2D BARCODES") > -1)
            barcodeTypeToScan.SetAll2D();
        else if (selectedItemText.IndexOf("AZTEC") > -1)
            barcodeTypeToScan.Aztec = true;
        else if (selectedItemText.IndexOf("CODABAR") > -1)
            barcodeTypeToScan.Codabar = true;
        else if (selectedItemText.IndexOf("CODE 39") > -1)
            barcodeTypeToScan.Code39 = true;
        else if (selectedItemText.IndexOf("CODE 128") > -1)
            barcodeTypeToScan.Code128 = true;
        else if (selectedItemText.IndexOf("DATAMATRIX") > -1)
            barcodeTypeToScan.DataMatrix = true;
        else if (selectedItemText.IndexOf("EAN 13") > -1)
            barcodeTypeToScan.EAN13 = true;
        else if (selectedItemText.IndexOf("GS1-128") > -1)
            barcodeTypeToScan.GS1 = true;
        else if (selectedItemText.IndexOf("GS1DATABAREXPANDED") > -1)
            barcodeTypeToScan.GS1DataBarExpanded = true;
        else if (selectedItemText.IndexOf("GS1DATABAREXPANDEDSTACKED") > -1)
            barcodeTypeToScan.GS1DataBarExpandedStacked = true;
        else if (selectedItemText.IndexOf("GS1DATABARLIMITED") > -1)
            barcodeTypeToScan.GS1DataBarLimited = true;
        else if (selectedItemText.IndexOf("GS1DATABAROMNIDIRECTIONAL") > -1)
            barcodeTypeToScan.GS1DataBarOmnidirectional = true;
        else if (selectedItemText.IndexOf("GS1DATABARSTACKED") > -1)
            barcodeTypeToScan.GS1DataBarStacked = true;
        else if (selectedItemText.IndexOf("I2OF5") > -1)
            barcodeTypeToScan.Interleaved2of5 = true;
        else if (selectedItemText.IndexOf("INTELLIGENT MAIL") > -1)
            barcodeTypeToScan.IntelligentMail = true;
        else if (selectedItemText.IndexOf("PATCH") > -1)
            barcodeTypeToScan.PatchCode = true;
        else if (selectedItemText.IndexOf("PDF 417") > -1)
            barcodeTypeToScan.PDF417 = true;
        else if (selectedItemText.IndexOf("QR CODE") > -1)
            barcodeTypeToScan.QRCode = true;
        else if (selectedItemText.IndexOf("UPCA") > -1)
            barcodeTypeToScan.UPCA = true;
        else if (selectedItemText.IndexOf("UPCE") > -1)
            barcodeTypeToScan.UPCE = true;
        else if (selectedItemText.IndexOf("MAXICODE") > -1)
            barcodeTypeToScan.MaxiCode = true;

        return barcodeTypeToScan;
    }


}

webcam.js
// WebcamJS v1.0.25
// Webcam library for capturing JPEG/PNG images in JavaScript
// Attempts getUserMedia, falls back to Flash
// Author: Joseph Huckaby: http://github.com/jhuckaby
// Based on JPEGCam: http://code.google.com/p/jpegcam/
// Copyright (c) 2012 - 2017 Joseph Huckaby
// Licensed under the MIT License

(function (window) {
    var _userMedia;

    // declare error types

    // inheritance pattern here:
    // https://stackoverflow.com/questions/783818/how-do-i-create-a-custom-error-in-javascript
    function FlashError() {
        var temp = Error.apply(this, arguments);
        temp.name = this.name = "FlashError";
        this.stack = temp.stack;
        this.message = temp.message;
    }

    function WebcamError() {
        var temp = Error.apply(this, arguments);
        temp.name = this.name = "WebcamError";
        this.stack = temp.stack;
        this.message = temp.message;
    }

    var IntermediateInheritor = function () { };
    IntermediateInheritor.prototype = Error.prototype;

    FlashError.prototype = new IntermediateInheritor();
    WebcamError.prototype = new IntermediateInheritor();

    var Webcam = {
        version: '1.0.25',

        // globals
        protocol: location.protocol.match(/https/i) ? 'https' : 'http',
        loaded: false,   // true when webcam movie finishes loading
        live: false,     // true when webcam is initialized and ready to snap
        userMedia: true, // true when getUserMedia is supported natively

        iOS: /iPad|iPhone|iPod/.test(navigator.userAgent) && !window.MSStream,

        params: {
            width: 0,
            height: 0,
            dest_width: 0,         // size of captured image
            dest_height: 0,        // these default to width/height
            image_format: 'jpeg',  // image format (may be jpeg or png)
            jpeg_quality: 90,      // jpeg image quality from 0 (worst) to 100 (best)
            enable_flash: true,    // enable flash fallback,
            force_flash: false,    // force flash mode,
            flip_horiz: false,     // flip image horiz (mirror mode)
            fps: 30,               // camera frames per second
            upload_name: 'webcam', // name of file in upload post data
            constraints: null,     // custom user media constraints,
            swfURL: '',            // URI to webcam.swf movie (defaults to the js location)
            flashNotDetectedText: 'ERROR: No Adobe Flash Player detected.  Webcam.js relies on Flash for browsers that do not support getUserMedia (like yours).',
            noInterfaceFoundText: 'No supported webcam interface found.',
            unfreeze_snap: true,    // Whether to unfreeze the camera after snap (defaults to true)
            iosPlaceholderText: 'Click here to open camera.',
            user_callback: null,    // callback function for snapshot (used if no user_callback parameter given to snap function)
            user_canvas: null       // user provided canvas for snapshot (used if no user_canvas parameter given to snap function)
        },

        errors: {
            FlashError: FlashError,
            WebcamError: WebcamError
        },

        hooks: {}, // callback hook functions

        init: function () {
            // initialize, check for getUserMedia support
            var self = this;

            // Setup getUserMedia, with polyfill for older browsers
            // Adapted from: https://developer.mozilla.org/en-US/docs/Web/API/MediaDevices/getUserMedia
            this.mediaDevices = (navigator.mediaDevices && navigator.mediaDevices.getUserMedia) ?
                navigator.mediaDevices : ((navigator.mozGetUserMedia || navigator.webkitGetUserMedia) ? {
                    getUserMedia: function (c) {
                        return new Promise(function (y, n) {
                            (navigator.mozGetUserMedia ||
                            navigator.webkitGetUserMedia).call(navigator, c, y, n);
                        });
                    }
                } : null);

            window.URL = window.URL || window.webkitURL || window.mozURL || window.msURL;
            this.userMedia = this.userMedia && !!this.mediaDevices && !!window.URL;

            if (this.iOS) {
                this.userMedia = null;
            }

            // Older versions of firefox (< 21) apparently claim support but user media does not actually work
            if (navigator.userAgent.match(/Firefox\D+(\d+)/)) {
                if (parseInt(RegExp.$1, 10) < 21) this.userMedia = null;
            }

            // Make sure media stream is closed when navigating away from page
            if (this.userMedia) {
                window.addEventListener('beforeunload', function (event) {
                    self.reset();
                });
            }
        },

        exifOrientation: function (binFile) {
            // extract orientation information from the image provided by iOS
            // algorithm based on exif-js
            var dataView = new DataView(binFile);
            if ((dataView.getUint8(0) != 0xFF) || (dataView.getUint8(1) != 0xD8)) {
                console.log('Not a valid JPEG file');
                return 0;
            }
            var offset = 2;
            var marker = null;
            while (offset < binFile.byteLength) {
                // find 0xFFE1 (225 marker)
                if (dataView.getUint8(offset) != 0xFF) {
                    console.log('Not a valid marker at offset ' + offset + ', found: ' + dataView.getUint8(offset));
                    return 0;
                }
                marker = dataView.getUint8(offset + 1);
                if (marker == 225) {
                    offset += 4;
                    var str = "";
                    for (n = 0; n < 4; n++) {
                        str += String.fromCharCode(dataView.getUint8(offset + n));
                    }
                    if (str != 'Exif') {
                        console.log('Not valid EXIF data found');
                        return 0;
                    }

                    offset += 6; // tiffOffset
                    var bigEnd = null;

                    // test for TIFF validity and endianness
                    if (dataView.getUint16(offset) == 0x4949) {
                        bigEnd = false;
                    } else if (dataView.getUint16(offset) == 0x4D4D) {
                        bigEnd = true;
                    } else {
                        console.log("Not valid TIFF data! (no 0x4949 or 0x4D4D)");
                        return 0;
                    }

                    if (dataView.getUint16(offset + 2, !bigEnd) != 0x002A) {
                        console.log("Not valid TIFF data! (no 0x002A)");
                        return 0;
                    }

                    var firstIFDOffset = dataView.getUint32(offset + 4, !bigEnd);
                    if (firstIFDOffset < 0x00000008) {
                        console.log("Not valid TIFF data! (First offset less than 8)", dataView.getUint32(offset + 4, !bigEnd));
                        return 0;
                    }

                    // extract orientation data
                    var dataStart = offset + firstIFDOffset;
                    var entries = dataView.getUint16(dataStart, !bigEnd);
                    for (var i = 0; i < entries; i++) {
                        var entryOffset = dataStart + i * 12 + 2;
                        if (dataView.getUint16(entryOffset, !bigEnd) == 0x0112) {
                            var valueType = dataView.getUint16(entryOffset + 2, !bigEnd);
                            var numValues = dataView.getUint32(entryOffset + 4, !bigEnd);
                            if (valueType != 3 && numValues != 1) {
                                console.log('Invalid EXIF orientation value type (' + valueType + ') or count (' + numValues + ')');
                                return 0;
                            }
                            var value = dataView.getUint16(entryOffset + 8, !bigEnd);
                            if (value < 1 || value > 8) {
                                console.log('Invalid EXIF orientation value (' + value + ')');
                                return 0;
                            }
                            return value;
                        }
                    }
                } else {
                    offset += 2 + dataView.getUint16(offset + 2);
                }
            }
            return 0;
        },

        fixOrientation: function (origObjURL, orientation, targetImg) {
            // fix image orientation based on exif orientation data
            // exif orientation information
            //    http://www.impulseadventure.com/photo/exif-orientation.html
            //    link source wikipedia (https://en.wikipedia.org/wiki/Exif#cite_note-20)
            var img = new Image();
            img.addEventListener('load', function (event) {
                var canvas = document.createElement('canvas');
                var ctx = canvas.getContext('2d');

                // switch width height if orientation needed
                if (orientation < 5) {
                    canvas.width = img.width;
                    canvas.height = img.height;
                } else {
                    canvas.width = img.height;
                    canvas.height = img.width;
                }

                // transform (rotate) image - see link at beginning this method
                switch (orientation) {
                    case 2: ctx.transform(-1, 0, 0, 1, img.width, 0); break;
                    case 3: ctx.transform(-1, 0, 0, -1, img.width, img.height); break;
                    case 4: ctx.transform(1, 0, 0, -1, 0, img.height); break;
                    case 5: ctx.transform(0, 1, 1, 0, 0, 0); break;
                    case 6: ctx.transform(0, 1, -1, 0, img.height, 0); break;
                    case 7: ctx.transform(0, -1, -1, 0, img.height, img.width); break;
                    case 8: ctx.transform(0, -1, 1, 0, 0, img.width); break;
                }

                ctx.drawImage(img, 0, 0);
                // pass rotated image data to the target image container
                targetImg.src = canvas.toDataURL();
            }, false);
            // start transformation by load event
            img.src = origObjURL;
        },

        attach: function (elem) {
            // create webcam preview and attach to DOM element
            // pass in actual DOM reference, ID, or CSS selector
            if (typeof (elem) == 'string') {
                elem = document.getElementById(elem) || document.querySelector(elem);
            }
            if (!elem) {
                return this.dispatch('error', new WebcamError("Could not locate DOM element to attach to."));
            }
            this.container = elem;
            elem.innerHTML = ''; // start with empty element

            // insert "peg" so we can insert our preview canvas adjacent to it later on
            var peg = document.createElement('div');
            elem.appendChild(peg);
            this.peg = peg;

            // set width/height if not already set
            if (!this.params.width) this.params.width = elem.offsetWidth;
            if (!this.params.height) this.params.height = elem.offsetHeight;

            // make sure we have a nonzero width and height at this point
            if (!this.params.width || !this.params.height) {
                return this.dispatch('error', new WebcamError("No width and/or height for webcam.  Please call set() first, or attach to a visible element."));
            }

            // set defaults for dest_width / dest_height if not set
            if (!this.params.dest_width) this.params.dest_width = this.params.width;
            if (!this.params.dest_height) this.params.dest_height = this.params.height;

            this.userMedia = _userMedia === undefined ? this.userMedia : _userMedia;
            // if force_flash is set, disable userMedia
            if (this.params.force_flash) {
                _userMedia = this.userMedia;
                this.userMedia = null;
            }

            // check for default fps
            if (typeof this.params.fps !== "number") this.params.fps = 30;

            // adjust scale if dest_width or dest_height is different
            var scaleX = this.params.width / this.params.dest_width;
            var scaleY = this.params.height / this.params.dest_height;

            if (this.userMedia) {
                // setup webcam video container
                var video = document.createElement('video');
                video.setAttribute('autoplay', 'autoplay');
                video.style.width = '' + this.params.dest_width + 'px';
                video.style.height = '' + this.params.dest_height + 'px';

                if ((scaleX != 1.0) || (scaleY != 1.0)) {
                    elem.style.overflow = 'hidden';
                    video.style.webkitTransformOrigin = '0px 0px';
                    video.style.mozTransformOrigin = '0px 0px';
                    video.style.msTransformOrigin = '0px 0px';
                    video.style.oTransformOrigin = '0px 0px';
                    video.style.transformOrigin = '0px 0px';
                    video.style.webkitTransform = 'scaleX(' + scaleX + ') scaleY(' + scaleY + ')';
                    video.style.mozTransform = 'scaleX(' + scaleX + ') scaleY(' + scaleY + ')';
                    video.style.msTransform = 'scaleX(' + scaleX + ') scaleY(' + scaleY + ')';
                    video.style.oTransform = 'scaleX(' + scaleX + ') scaleY(' + scaleY + ')';
                    video.style.transform = 'scaleX(' + scaleX + ') scaleY(' + scaleY + ')';
                }

                // add video element to dom
                elem.appendChild(video);
                this.video = video;

                // ask user for access to their camera
                var self = this;
                this.mediaDevices.getUserMedia({
                    "audio": false,
                    "video": this.params.constraints || {
                        mandatory: {
                            minWidth: this.params.dest_width,
                            minHeight: this.params.dest_height
                        }
                    }
                })
                .then(function (stream) {
                    // got access, attach stream to video
                    video.onloadedmetadata = function (e) {
                        self.stream = stream;
                        self.loaded = true;
                        self.live = true;
                        self.dispatch('load');
                        self.dispatch('live');
                        self.flip();
                    };
                    // as window.URL.createObjectURL() is deprecated, adding a check so that it works in Safari.
                    // older browsers may not have srcObject
                    if ("srcObject" in video) {
                        video.srcObject = stream;
                    }
                    else {
                        // using URL.createObjectURL() as fallback for old browsers
                        video.src = window.URL.createObjectURL(stream);
                    }
                })
                .catch(function (err) {
                    // JH 2016-07-31 Instead of dispatching error, now falling back to Flash if userMedia fails (thx @john2014)
                    // JH 2016-08-07 But only if flash is actually installed -- if not, dispatch error here and now.
                    if (self.params.enable_flash && self.detectFlash()) {
                        setTimeout(function () { self.params.force_flash = 1; self.attach(elem); }, 1);
                    }
                    else {
                        self.dispatch('error', err);
                    }
                });
            }
            else if (this.iOS) {
                // prepare HTML elements
                var div = document.createElement('div');
                div.id = this.container.id + '-ios_div';
                div.className = 'webcamjs-ios-placeholder';
                div.style.width = '' + this.params.width + 'px';
                div.style.height = '' + this.params.height + 'px';
                div.style.textAlign = 'center';
                div.style.display = 'table-cell';
                div.style.verticalAlign = 'middle';
                div.style.backgroundRepeat = 'no-repeat';
                div.style.backgroundSize = 'contain';
                div.style.backgroundPosition = 'center';
                var span = document.createElement('span');
                span.className = 'webcamjs-ios-text';
                span.innerHTML = this.params.iosPlaceholderText;
                div.appendChild(span);
                var img = document.createElement('img');
                img.id = this.container.id + '-ios_img';
                img.style.width = '' + this.params.dest_width + 'px';
                img.style.height = '' + this.params.dest_height + 'px';
                img.style.display = 'none';
                div.appendChild(img);
                var input = document.createElement('input');
                input.id = this.container.id + '-ios_input';
                input.setAttribute('type', 'file');
                input.setAttribute('accept', 'image/*');
                input.setAttribute('capture', 'camera');

                var self = this;
                var params = this.params;
                // add input listener to load the selected image
                input.addEventListener('change', function (event) {
                    if (event.target.files.length > 0 && event.target.files[0].type.indexOf('image/') == 0) {
                        var objURL = URL.createObjectURL(event.target.files[0]);

                        // load image with auto scale and crop
                        var image = new Image();
                        image.addEventListener('load', function (event) {
                            var canvas = document.createElement('canvas');
                            canvas.width = params.dest_width;
                            canvas.height = params.dest_height;
                            var ctx = canvas.getContext('2d');

                            // crop and scale image for final size
                            ratio = Math.min(image.width / params.dest_width, image.height / params.dest_height);
                            var sw = params.dest_width * ratio;
                            var sh = params.dest_height * ratio;
                            var sx = (image.width - sw) / 2;
                            var sy = (image.height - sh) / 2;
                            ctx.drawImage(image, sx, sy, sw, sh, 0, 0, params.dest_width, params.dest_height);

                            var dataURL = canvas.toDataURL();
                            img.src = dataURL;
                            div.style.backgroundImage = "url('" + dataURL + "')";
                        }, false);

                        // read EXIF data
                        var fileReader = new FileReader();
                        fileReader.addEventListener('load', function (e) {
                            var orientation = self.exifOrientation(e.target.result);
                            if (orientation > 1) {
                                // image need to rotate (see comments on fixOrientation method for more information)
                                // transform image and load to image object
                                self.fixOrientation(objURL, orientation, image);
                            } else {
                                // load image data to image object
                                image.src = objURL;
                            }
                        }, false);

                        // Convert image data to blob format
                        var http = new XMLHttpRequest();
                        http.open("GET", objURL, true);
                        http.responseType = "blob";
                        http.onload = function (e) {
                            if (this.status == 200 || this.status === 0) {
                                fileReader.readAsArrayBuffer(this.response);
                            }
                        };
                        http.send();

                    }
                }, false);
                input.style.display = 'none';
                elem.appendChild(input);
                // make div clickable for open camera interface
                div.addEventListener('click', function (event) {
                    if (params.user_callback) {
                        // global user_callback defined - create the snapshot
                        self.snap(params.user_callback, params.user_canvas);
                    } else {
                        // no global callback definied for snapshot, load image and wait for external snap method call
                        input.style.display = 'block';
                        input.focus();
                        input.click();
                        input.style.display = 'none';
                    }
                }, false);
                elem.appendChild(div);
                this.loaded = true;
                this.live = true;
            }
            else if (this.params.enable_flash && this.detectFlash()) {
                // flash fallback
                window.Webcam = Webcam; // needed for flash-to-js interface
                var div = document.createElement('div');
                div.innerHTML = this.getSWFHTML();
                elem.appendChild(div);
            }
            else {
                this.dispatch('error', new WebcamError(this.params.noInterfaceFoundText));
            }

            // setup final crop for live preview
            if (this.params.crop_width && this.params.crop_height) {
                var scaled_crop_width = Math.floor(this.params.crop_width * scaleX);
                var scaled_crop_height = Math.floor(this.params.crop_height * scaleY);

                elem.style.width = '' + scaled_crop_width + 'px';
                elem.style.height = '' + scaled_crop_height + 'px';
                elem.style.overflow = 'hidden';

                elem.scrollLeft = Math.floor((this.params.width / 2) - (scaled_crop_width / 2));
                elem.scrollTop = Math.floor((this.params.height / 2) - (scaled_crop_height / 2));
            }
            else {
                // no crop, set size to desired
                elem.style.width = '' + this.params.width + 'px';
                elem.style.height = '' + this.params.height + 'px';
            }
        },

        reset: function () {
            // shutdown camera, reset to potentially attach again
            if (this.preview_active) this.unfreeze();

            // attempt to fix issue #64
            this.unflip();

            if (this.userMedia) {
                if (this.stream) {
                    if (this.stream.getVideoTracks) {
                        // get video track to call stop on it
                        var tracks = this.stream.getVideoTracks();
                        if (tracks && tracks[0] && tracks[0].stop) tracks[0].stop();
                    }
                    else if (this.stream.stop) {
                        // deprecated, may be removed in future
                        this.stream.stop();
                    }
                }
                delete this.stream;
                delete this.video;
            }

            if ((this.userMedia !== true) && this.loaded && !this.iOS) {
                // call for turn off camera in flash
                var movie = this.getMovie();
                if (movie && movie._releaseCamera) movie._releaseCamera();
            }

            if (this.container) {
                this.container.innerHTML = '';
                delete this.container;
            }

            this.loaded = false;
            this.live = false;
        },

        set: function () {
            // set one or more params
            // variable argument list: 1 param = hash, 2 params = key, value
            if (arguments.length == 1) {
                for (var key in arguments[0]) {
                    this.params[key] = arguments[0][key];
                }
            }
            else {
                this.params[arguments[0]] = arguments[1];
            }
        },

        on: function (name, callback) {
            // set callback hook
            name = name.replace(/^on/i, '').toLowerCase();
            if (!this.hooks[name]) this.hooks[name] = [];
            this.hooks[name].push(callback);
        },

        off: function (name, callback) {
            // remove callback hook
            name = name.replace(/^on/i, '').toLowerCase();
            if (this.hooks[name]) {
                if (callback) {
                    // remove one selected callback from list
                    var idx = this.hooks[name].indexOf(callback);
                    if (idx > -1) this.hooks[name].splice(idx, 1);
                }
                else {
                    // no callback specified, so clear all
                    this.hooks[name] = [];
                }
            }
        },

        dispatch: function () {
            // fire hook callback, passing optional value to it
            var name = arguments[0].replace(/^on/i, '').toLowerCase();
            var args = Array.prototype.slice.call(arguments, 1);

            if (this.hooks[name] && this.hooks[name].length) {
                for (var idx = 0, len = this.hooks[name].length; idx < len; idx++) {
                    var hook = this.hooks[name][idx];

                    if (typeof (hook) == 'function') {
                        // callback is function reference, call directly
                        hook.apply(this, args);
                    }
                    else if ((typeof (hook) == 'object') && (hook.length == 2)) {
                        // callback is PHP-style object instance method
                        hook[0][hook[1]].apply(hook[0], args);
                    }
                    else if (window[hook]) {
                        // callback is global function name
                        window[hook].apply(window, args);
                    }
                } // loop
                return true;
            }
            else if (name == 'error') {
                var message;
                if ((args[0] instanceof FlashError) || (args[0] instanceof WebcamError)) {
                    message = args[0].message;
                } else {
                    message = "Could not access webcam: " + args[0].name + ": " +
                        args[0].message + " " + args[0].toString();
                }

                // default error handler if no custom one specified
                alert("Webcam.js Error: " + message);
            }

            return false; // no hook defined
        },

        setSWFLocation: function (value) {
            // for backward compatibility.
            this.set('swfURL', value);
        },

        detectFlash: function () {
            // return true if browser supports flash, false otherwise
            // Code snippet borrowed from: https://github.com/swfobject/swfobject
            var SHOCKWAVE_FLASH = "Shockwave Flash",
                SHOCKWAVE_FLASH_AX = "ShockwaveFlash.ShockwaveFlash",
                FLASH_MIME_TYPE = "application/x-shockwave-flash",
                win = window,
                nav = navigator,
                hasFlash = false;

            if (typeof nav.plugins !== "undefined" && typeof nav.plugins[SHOCKWAVE_FLASH] === "object") {
                var desc = nav.plugins[SHOCKWAVE_FLASH].description;
                if (desc && (typeof nav.mimeTypes !== "undefined" && nav.mimeTypes[FLASH_MIME_TYPE] && nav.mimeTypes[FLASH_MIME_TYPE].enabledPlugin)) {
                    hasFlash = true;
                }
            }
            else if (typeof win.ActiveXObject !== "undefined") {
                try {
                    var ax = new ActiveXObject(SHOCKWAVE_FLASH_AX);
                    if (ax) {
                        var ver = ax.GetVariable("$version");
                        if (ver) hasFlash = true;
                    }
                }
                catch (e) {; }
            }

            return hasFlash;
        },

        getSWFHTML: function () {
            // Return HTML for embedding flash based webcam capture movie		
            var html = '',
                swfURL = this.params.swfURL;

            // make sure we aren't running locally (flash doesn't work)
            if (location.protocol.match(/file/)) {
                this.dispatch('error', new FlashError("Flash does not work from local disk.  Please run from a web server."));
                return '<h3 style="color:red">ERROR: the Webcam.js Flash fallback does not work from local disk.  Please run it from a web server.</h3>';
            }

            // make sure we have flash
            if (!this.detectFlash()) {
                this.dispatch('error', new FlashError("Adobe Flash Player not found.  Please install from get.adobe.com/flashplayer and try again."));
                return '<h3 style="color:red">' + this.params.flashNotDetectedText + '</h3>';
            }

            // set default swfURL if not explicitly set
            if (!swfURL) {
                // find our script tag, and use that base URL
                var base_url = '';
                var scpts = document.getElementsByTagName('script');
                for (var idx = 0, len = scpts.length; idx < len; idx++) {
                    var src = scpts[idx].getAttribute('src');
                    if (src && src.match(/\/webcam(\.min)?\.js/)) {
                        base_url = src.replace(/\/webcam(\.min)?\.js.*$/, '');
                        idx = len;
                    }
                }
                if (base_url) swfURL = base_url + '/webcam.swf';
                else swfURL = 'webcam.swf';
            }

            // if this is the user's first visit, set flashvar so flash privacy settings panel is shown first
            if (window.localStorage && !localStorage.getItem('visited')) {
                this.params.new_user = 1;
                localStorage.setItem('visited', 1);
            }

            // construct flashvars string
            var flashvars = '';
            for (var key in this.params) {
                if (flashvars) flashvars += '&';
                flashvars += key + '=' + escape(this.params[key]);
            }

            // construct object/embed tag
            html += '<object classid="clsid:d27cdb6e-ae6d-11cf-96b8-444553540000" type="application/x-shockwave-flash" codebase="' + this.protocol + '://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=9,0,0,0" width="' + this.params.width + '" height="' + this.params.height + '" id="webcam_movie_obj" align="middle"><param name="wmode" value="opaque" /><param name="allowScriptAccess" value="always" /><param name="allowFullScreen" value="false" /><param name="movie" value="' + swfURL + '" /><param name="loop" value="false" /><param name="menu" value="false" /><param name="quality" value="best" /><param name="bgcolor" value="#ffffff" /><param name="flashvars" value="' + flashvars + '"/><embed id="webcam_movie_embed" src="' + swfURL + '" wmode="opaque" loop="false" menu="false" quality="best" bgcolor="#ffffff" width="' + this.params.width + '" height="' + this.params.height + '" name="webcam_movie_embed" align="middle" allowScriptAccess="always" allowFullScreen="false" type="application/x-shockwave-flash" pluginspage="http://www.macromedia.com/go/getflashplayer" flashvars="' + flashvars + '"></embed></object>';

            return html;
        },

        getMovie: function () {
            // get reference to movie object/embed in DOM
            if (!this.loaded) return this.dispatch('error', new FlashError("Flash Movie is not loaded yet"));
            var movie = document.getElementById('webcam_movie_obj');
            if (!movie || !movie._snap) movie = document.getElementById('webcam_movie_embed');
            if (!movie) this.dispatch('error', new FlashError("Cannot locate Flash movie in DOM"));
            return movie;
        },

        freeze: function () {
            // show preview, freeze camera
            var self = this;
            var params = this.params;

            // kill preview if already active
            if (this.preview_active) this.unfreeze();

            // determine scale factor
            var scaleX = this.params.width / this.params.dest_width;
            var scaleY = this.params.height / this.params.dest_height;

            // must unflip container as preview canvas will be pre-flipped
            this.unflip();

            // calc final size of image
            var final_width = params.crop_width || params.dest_width;
            var final_height = params.crop_height || params.dest_height;

            // create canvas for holding preview
            var preview_canvas = document.createElement('canvas');
            preview_canvas.width = final_width;
            preview_canvas.height = final_height;
            var preview_context = preview_canvas.getContext('2d');

            // save for later use
            this.preview_canvas = preview_canvas;
            this.preview_context = preview_context;

            // scale for preview size
            if ((scaleX != 1.0) || (scaleY != 1.0)) {
                preview_canvas.style.webkitTransformOrigin = '0px 0px';
                preview_canvas.style.mozTransformOrigin = '0px 0px';
                preview_canvas.style.msTransformOrigin = '0px 0px';
                preview_canvas.style.oTransformOrigin = '0px 0px';
                preview_canvas.style.transformOrigin = '0px 0px';
                preview_canvas.style.webkitTransform = 'scaleX(' + scaleX + ') scaleY(' + scaleY + ')';
                preview_canvas.style.mozTransform = 'scaleX(' + scaleX + ') scaleY(' + scaleY + ')';
                preview_canvas.style.msTransform = 'scaleX(' + scaleX + ') scaleY(' + scaleY + ')';
                preview_canvas.style.oTransform = 'scaleX(' + scaleX + ') scaleY(' + scaleY + ')';
                preview_canvas.style.transform = 'scaleX(' + scaleX + ') scaleY(' + scaleY + ')';
            }

            // take snapshot, but fire our own callback
            this.snap(function () {
                // add preview image to dom, adjust for crop
                preview_canvas.style.position = 'relative';
                preview_canvas.style.left = '' + self.container.scrollLeft + 'px';
                preview_canvas.style.top = '' + self.container.scrollTop + 'px';

                self.container.insertBefore(preview_canvas, self.peg);
                self.container.style.overflow = 'hidden';

                // set flag for user capture (use preview)
                self.preview_active = true;

            }, preview_canvas);
        },

        unfreeze: function () {
            // cancel preview and resume live video feed
            if (this.preview_active) {
                // remove preview canvas
                this.container.removeChild(this.preview_canvas);
                delete this.preview_context;
                delete this.preview_canvas;

                // unflag
                this.preview_active = false;

                // re-flip if we unflipped before
                this.flip();
            }
        },

        flip: function () {
            // flip container horiz (mirror mode) if desired
            if (this.params.flip_horiz) {
                var sty = this.container.style;
                sty.webkitTransform = 'scaleX(-1)';
                sty.mozTransform = 'scaleX(-1)';
                sty.msTransform = 'scaleX(-1)';
                sty.oTransform = 'scaleX(-1)';
                sty.transform = 'scaleX(-1)';
                sty.filter = 'FlipH';
                sty.msFilter = 'FlipH';
            }
        },

        unflip: function () {
            // unflip container horiz (mirror mode) if desired
            if (this.params.flip_horiz) {
                var sty = this.container.style;
                sty.webkitTransform = 'scaleX(1)';
                sty.mozTransform = 'scaleX(1)';
                sty.msTransform = 'scaleX(1)';
                sty.oTransform = 'scaleX(1)';
                sty.transform = 'scaleX(1)';
                sty.filter = '';
                sty.msFilter = '';
            }
        },

        savePreview: function (user_callback, user_canvas) {
            // save preview freeze and fire user callback
            var params = this.params;
            var canvas = this.preview_canvas;
            var context = this.preview_context;

            // render to user canvas if desired
            if (user_canvas) {
                var user_context = user_canvas.getContext('2d');
                user_context.drawImage(canvas, 0, 0);
            }

            // fire user callback if desired
            user_callback(
                user_canvas ? null : canvas.toDataURL('image/' + params.image_format, params.jpeg_quality / 100),
                canvas,
                context
            );

            // remove preview
            if (this.params.unfreeze_snap) this.unfreeze();
        },

        snap: function (user_callback, user_canvas) {
            // use global callback and canvas if not defined as parameter
            if (!user_callback) user_callback = this.params.user_callback;
            if (!user_canvas) user_canvas = this.params.user_canvas;

            // take snapshot and return image data uri
            var self = this;
            var params = this.params;

            if (!this.loaded) return this.dispatch('error', new WebcamError("Webcam is not loaded yet"));
            // if (!this.live) return this.dispatch('error', new WebcamError("Webcam is not live yet"));
            if (!user_callback) return this.dispatch('error', new WebcamError("Please provide a callback function or canvas to snap()"));

            // if we have an active preview freeze, use that
            if (this.preview_active) {
                this.savePreview(user_callback, user_canvas);
                return null;
            }

            // create offscreen canvas element to hold pixels
            var canvas = document.createElement('canvas');
            canvas.width = this.params.dest_width;
            canvas.height = this.params.dest_height;
            var context = canvas.getContext('2d');

            // flip canvas horizontally if desired
            if (this.params.flip_horiz) {
                context.translate(params.dest_width, 0);
                context.scale(-1, 1);
            }

            // create inline function, called after image load (flash) or immediately (native)
            var func = function () {
                // render image if needed (flash)
                if (this.src && this.width && this.height) {
                    context.drawImage(this, 0, 0, params.dest_width, params.dest_height);
                }

                // crop if desired
                if (params.crop_width && params.crop_height) {
                    var crop_canvas = document.createElement('canvas');
                    crop_canvas.width = params.crop_width;
                    crop_canvas.height = params.crop_height;
                    var crop_context = crop_canvas.getContext('2d');

                    crop_context.drawImage(canvas,
                        Math.floor((params.dest_width / 2) - (params.crop_width / 2)),
                        Math.floor((params.dest_height / 2) - (params.crop_height / 2)),
                        params.crop_width,
                        params.crop_height,
                        0,
                        0,
                        params.crop_width,
                        params.crop_height
                    );

                    // swap canvases
                    context = crop_context;
                    canvas = crop_canvas;
                }

                // render to user canvas if desired
                if (user_canvas) {
                    var user_context = user_canvas.getContext('2d');
                    user_context.drawImage(canvas, 0, 0);
                }

                // fire user callback if desired
                user_callback(
                    user_canvas ? null : canvas.toDataURL('image/' + params.image_format, params.jpeg_quality / 100),
                    canvas,
                    context
                );
            };

            // grab image frame from userMedia or flash movie
            if (this.userMedia) {
                // native implementation
                context.drawImage(this.video, 0, 0, this.params.dest_width, this.params.dest_height);

                // fire callback right away
                func();
            }
            else if (this.iOS) {
                var div = document.getElementById(this.container.id + '-ios_div');
                var img = document.getElementById(this.container.id + '-ios_img');
                var input = document.getElementById(this.container.id + '-ios_input');
                // function for handle snapshot event (call user_callback and reset the interface)
                iFunc = function (event) {
                    func.call(img);
                    img.removeEventListener('load', iFunc);
                    div.style.backgroundImage = 'none';
                    img.removeAttribute('src');
                    input.value = null;
                };
                if (!input.value) {
                    // No image selected yet, activate input field
                    img.addEventListener('load', iFunc);
                    input.style.display = 'block';
                    input.focus();
                    input.click();
                    input.style.display = 'none';
                } else {
                    // Image already selected
                    iFunc(null);
                }
            }
            else {
                // flash fallback
                var raw_data = this.getMovie()._snap();

                // render to image, fire callback when complete
                var img = new Image();
                img.onload = func;
                img.src = 'data:image/' + this.params.image_format + ';base64,' + raw_data;
            }

            return null;
        },

        configure: function (panel) {
            // open flash configuration panel -- specify tab name:
            // "camera", "privacy", "default", "localStorage", "microphone", "settingsManager"
            if (!panel) panel = "camera";
            this.getMovie()._configure(panel);
        },

        flashNotify: function (type, msg) {
            // receive notification from flash about event
            switch (type) {
                case 'flashLoadComplete':
                    // movie loaded successfully
                    this.loaded = true;
                    this.dispatch('load');
                    break;

                case 'cameraLive':
                    // camera is live and ready to snap
                    this.live = true;
                    this.dispatch('live');
                    break;

                case 'error':
                    // Flash error
                    this.dispatch('error', new FlashError(msg));
                    break;

                default:
                    // catch-all event, just in case
                    // console.log("webcam flash_notify: " + type + ": " + msg);
                    break;
            }
        },

        b64ToUint6: function (nChr) {
            // convert base64 encoded character to 6-bit integer
            // from: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Base64_encoding_and_decoding
            return nChr > 64 && nChr < 91 ? nChr - 65
                : nChr > 96 && nChr < 123 ? nChr - 71
                : nChr > 47 && nChr < 58 ? nChr + 4
                : nChr === 43 ? 62 : nChr === 47 ? 63 : 0;
        },

        base64DecToArr: function (sBase64, nBlocksSize) {
            // convert base64 encoded string to Uintarray
            // from: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Base64_encoding_and_decoding
            var sB64Enc = sBase64.replace(/[^A-Za-z0-9\+\/]/g, ""), nInLen = sB64Enc.length,
                nOutLen = nBlocksSize ? Math.ceil((nInLen * 3 + 1 >> 2) / nBlocksSize) * nBlocksSize : nInLen * 3 + 1 >> 2,
                taBytes = new Uint8Array(nOutLen);

            for (var nMod3, nMod4, nUint24 = 0, nOutIdx = 0, nInIdx = 0; nInIdx < nInLen; nInIdx++) {
                nMod4 = nInIdx & 3;
                nUint24 |= this.b64ToUint6(sB64Enc.charCodeAt(nInIdx)) << 18 - 6 * nMod4;
                if (nMod4 === 3 || nInLen - nInIdx === 1) {
                    for (nMod3 = 0; nMod3 < 3 && nOutIdx < nOutLen; nMod3++, nOutIdx++) {
                        taBytes[nOutIdx] = nUint24 >>> (16 >>> nMod3 & 24) & 255;
                    }
                    nUint24 = 0;
                }
            }
            return taBytes;
        },

        upload: function (image_data_uri, target_url, callback) {
            // submit image data to server using binary AJAX
            var form_elem_name = this.params.upload_name || 'webcam';

            // detect image format from within image_data_uri
            var image_fmt = '';
            if (image_data_uri.match(/^data\:image\/(\w+)/))
                image_fmt = RegExp.$1;
            else
                throw "Cannot locate image format in Data URI";

            // extract raw base64 data from Data URI
            var raw_image_data = image_data_uri.replace(/^data\:image\/\w+\;base64\,/, '');

            // contruct use AJAX object
            var http = new XMLHttpRequest();
            http.open("POST", target_url, true);

            // setup progress events
            if (http.upload && http.upload.addEventListener) {
                http.upload.addEventListener('progress', function (e) {
                    if (e.lengthComputable) {
                        var progress = e.loaded / e.total;
                        Webcam.dispatch('uploadProgress', progress, e);
                    }
                }, false);
            }

            // completion handler
            var self = this;
            http.onload = function () {
                if (callback) callback.apply(self, [http.status, http.responseText, http.statusText]);
                Webcam.dispatch('uploadComplete', http.status, http.responseText, http.statusText);
            };

            // create a blob and decode our base64 to binary
            var blob = new Blob([this.base64DecToArr(raw_image_data)], { type: 'image/' + image_fmt });

            // stuff into a form, so servers can easily receive it as a standard file upload
            var form = new FormData();
            form.append(form_elem_name, blob, form_elem_name + "." + image_fmt.replace(/e/, ''));

            // send data to server
            http.send(form);
        }

    };

    Webcam.init();

    if (typeof define === 'function' && define.amd) {
        define(function () { return Webcam; });
    }
    else if (typeof module === 'object' && module.exports) {
        module.exports = Webcam;
    }
    else {
        window.Webcam = Webcam;
    }

}(window));

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