Image masks

Docotic.Pdf Library Help > Samples > Images > Image masks

This sample shows how to use mask images.

You can add a transparent image to your PDF document using PdfDocument.AddImage method with a mask image as a parameter. Mask image must have the same width and height as an image to be made transparent and their pixel data must be encoded using 1 bit per pixel.

All pixels in the resulting image that correspond to the black pixels of a mask image will be drawn unchanged. All pixels in the resulting image that correspond to the white pixels of a mask image will not be drawn. Black pixels in a mask image are encoded using '0' bits. White pixels in a mask image are encoded using '1' bits.

CopyC#

using System.Diagnostics;
using System.Drawing;

namespace BitMiracle.Docotic.Pdf.Samples
{
    public static class ImageMasks
    {
        public static void Main()
        {
            // NOTE: 
            // When used in trial mode, the library imposes some restrictions.
            // Please visit http://bitmiracle.com/pdf-library/trial-restrictions.aspx
            // for more information.

            PdfDocument pdf = new PdfDocument();
            PdfCanvas canvas = pdf.Pages[0].Canvas;
            canvas.Resolution = 150;

            canvas.Brush.Color = new PdfRgbColor(0, 255, 0);
            canvas.DrawRectangle(new RectangleF(50, 450, 1150, 150), PdfDrawMode.Fill);

            PdfImage image = pdf.AddImage("Sample data/pink.png", "Sample data/pinkMask.tif");
            canvas.DrawImage(image, 550, 200);

            string pathToFile = "ImageMasks.pdf";
            pdf.Save(pathToFile);
            pdf.Dispose();

            Process.Start(pathToFile);
        }
    }
}

CopyVB.NET

Imports System.Diagnostics
Imports System.Drawing

Imports BitMiracle.Docotic.Pdf

Namespace BitMiracle.Docotic.Pdf.Samples
    Public NotInheritable Class ImageMasks
        Public Shared Sub Main()
            ' NOTE: 
            ' When used in trial mode, the library imposes some restrictions.
            ' Please visit http://bitmiracle.com/pdf-library/trial-restrictions.aspx
            ' for more information.


            Dim pdf As New PdfDocument()
            Dim canvas As PdfCanvas = pdf.Pages(0).Canvas
            canvas.Resolution = 150

            canvas.Brush.Color = New PdfRgbColor(0, 255, 0)
            canvas.DrawRectangle(New RectangleF(50, 450, 1150, 150), PdfDrawMode.Fill)

            Dim image As PdfImage = pdf.AddImage("Sample data/pink.png", "Sample data/pinkMask.tif")
            canvas.DrawImage(image, 550, 200)

            Dim pathToFile As String = "ImageMasks.pdf"
            pdf.Save(pathToFile)
            pdf.Dispose()

            Process.Start(pathToFile)
        End Sub
    End Class
End Namespace