Set Image Preprocessing Filters - C++ (Unmanaged)
BarCode Reader SDK sample in C++ (Unmanaged) demonstrating ‘Set Image Preprocessing Filters’
ImagePreprocessingFilters.cpp
#include "stdafx.h"
///
/// This example demonstrates the use of image filters to improve the decoding confidence or speed.
///
#import "c:\\Program Files\\Bytescout BarCode Reader SDK\\net2.00\\Bytescout.BarCodeReader.tlb" raw_interfaces_only
using namespace Bytescout_BarCodeReader;
void PrintFoundBarcodes(IReaderPtr pIReader);
int _tmain(int argc, _TCHAR* argv[])
{
// Initialize COM.
HRESULT hr = CoInitialize(NULL);
// Create the interface pointer.
IReaderPtr pIReader(__uuidof(Reader));
// set the registration name and key
_bstr_t registrationName(L"DEMO");
pIReader->put_RegistrationName(registrationName);
_bstr_t registrationKey(L"DEMO");
pIReader->put_RegistrationKey(registrationKey);
// Set barcode type to find
_BarcodeTypeSelectorPtr pBarcodeTypesToFind;
pIReader->get_BarcodeTypesToFind(&pBarcodeTypesToFind);
pBarcodeTypesToFind->put_Code128(VARIANT_TRUE);
// Get image filters collection
_ImagePreprocessingFiltersCollection* pIImageFilters;
pIReader->get_ImagePreprocessingFilters(&pIImageFilters);
// WORKING WITH LOW CONTRAST BARCODE IMAGES
pIImageFilters->AddContrast(40);
// Add contrast adjustment for low-contrast image
_bstr_t sampleFile1(L".\\low-contrast-barcode.png");
wprintf(L"Image \"%s\"\n", static_cast<wchar_t*>(sampleFile1));
pIReader->ReadFromFile(sampleFile1);
PrintFoundBarcodes(pIReader);
pIImageFilters->Clear();
// WORKING WITH NOISY BARCODE IMAGES
// Add median filter to lower a noise
pIImageFilters->AddMedian();
_bstr_t sampleFile2(L".\\noisy-barcode.png");
wprintf(L"Image \"%s\"\n", static_cast<wchar_t*>(sampleFile2));
pIReader->ReadFromFile(sampleFile2);
PrintFoundBarcodes(pIReader);
pIImageFilters->Clear();
// WORKING WITH DENSE AND ILLEGIBLE BARCODES
// Add the scale filter to enlarge the barcode to make gaps between bars more distinguishable
pIImageFilters->AddScale_2(2.0);
_bstr_t sampleFile3(L".\\too-dense-barcode.png");
wprintf(L"Image \"%s\"\n", static_cast<wchar_t*>(sampleFile3));
pIReader->ReadFromFile(sampleFile3);
PrintFoundBarcodes(pIReader);
pIImageFilters->Clear();
// REMOVE EMPTY MARGINS FROM IMAGE TO SPEED UP THE PROCESSING
// Add the crop filter to cut off empty margins from the image.
// This will not improve the recognition quality but may speed up the processing
// if you enabled multiple barcode types to search.
pIImageFilters->AddCropDark();
_bstr_t sampleFile4(L".\\barcode-with-large-margins.png");
wprintf(L"Image \"%s\"\n", static_cast<wchar_t*>(sampleFile4));
pIReader->ReadFromFile(sampleFile4);
PrintFoundBarcodes(pIReader);
pIImageFilters->Clear();
// Uninitialize COM.
CoUninitialize();
// Wait until user press any key
system("pause");
return 0;
}
void PrintFoundBarcodes(IReaderPtr pIReader)
{
// Get found barcode count
long count;
pIReader->get_FoundCount(&count);
// Get found barcode information
for (int i = 0; i < count; i++)
{
SymbologyType type;
pIReader->GetFoundBarcodeType(i, &type);
wprintf(L"Barcode type: %d\n", type);
float confidence;
pIReader->GetFoundBarcodeConfidence(i, &confidence);
wprintf(L"Barcode confidence: %f\n", confidence);
BSTR bstrValue;
pIReader->GetFoundBarcodeValue(i, &bstrValue);
wprintf(L"Barcode value: %s\n", bstrValue);
::SysFreeString(bstrValue);
wprintf(L"\n");
}
if (count == 0)
{
wprintf(L"No barcodes found.\n");
}
}
stdafx.cpp
// stdafx.cpp : source file that includes just the standard includes
// CPPExample.pch will be the pre-compiled header
// stdafx.obj will contain the pre-compiled type information
#include "stdafx.h"
// TODO: reference any additional headers you need in STDAFX.H
// and not in this file
stdafx.h
// stdafx.h : include file for standard system include files,
// or project specific include files that are used frequently, but
// are changed infrequently
//
#pragma once
#include "targetver.h"
#include <stdio.h>
#include <tchar.h>
// TODO: reference additional headers your program requires here
targetver.h
#pragma once
// Including SDKDDKVer.h defines the highest available Windows platform.
// If you wish to build your application for a previous Windows platform, include WinSDKVer.h and
// set the _WIN32_WINNT macro to the platform you wish to support before including SDKDDKVer.h.
#include <SDKDDKVer.h>