Set Invisible Text Over Image in PDF - VB.NET
PDF SDK sample in VB.NET demonstrating ‘Set Invisible Text Over Image in PDF’
Program.vb
Imports Bytescout.PDF
''' <summary>
''' This example demonstrates how to create PDF document from scanned document image and add invisible text over it.
''' </summary>
Class Program
Shared Sub Main()
' Create new PDF document
Dim pdfDocument = New Document()
pdfDocument.RegistrationName = "demo"
pdfDocument.RegistrationKey = "demo"
' If you wish to load an existing document uncomment the line below And comment the Add page section instead
' pdfDocument.Load(".\existing_document.pdf")
' Load image from file to System.Drawing.Image object (we need it to get the image resolution)
Dim sysImage As System.Drawing.Image = System.Drawing.Image.FromFile(".\scanned-invoice.png")
' Compute image size in PDF units (Points)
Dim widthInPoints As Single = sysImage.Width / sysImage.HorizontalResolution * 72.0F
Dim heightInPoints As Single = sysImage.Height / sysImage.VerticalResolution * 72.0F
' Create page of computed size
Dim page = New Page(widthInPoints, heightInPoints)
' Add page to the document
pdfDocument.Pages.Add(page)
Dim canvas = page.Canvas
' Create Bytescout.PDF.Image object from loaded image
Dim pdfImage = New Image(sysImage)
' Draw the image
canvas.DrawImage(pdfImage, 0, 0, widthInPoints, heightInPoints)
' Dispose the System.Drawing.Image object to free resources
sysImage.Dispose()
' Create brush
Dim transparentBrush As SolidBrush = New SolidBrush(New ColorGray(0))
' ... and make it transparent
transparentBrush.Opacity = 0
' Draw text with transparent brush
Dim font16 As Font = New Font(StandardFonts.Helvetica, 16)
canvas.DrawString("Your Company Name", font16, transparentBrush, 40, 40)
' Draw another text
Dim font10 As Font = New Font(StandardFonts.Helvetica, 10)
canvas.DrawString("Your Address", font10, transparentBrush, 40, 80)
' Save document to file
pdfDocument.Save("result.pdf")
' Cleanup
pdfDocument.Dispose()
' Open document in default PDF viewer app
Process.Start("result.pdf")
End Sub
End Class
Resources.Designer.vb
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