TransparentColor Property

C#
Visual Basic
WinRT C#
Objective-C
Java
WinRT JavaScript
C++

public RasterColor TransparentColor {get; set;}

'Declaration
 
Public Property TransparentColor As RasterColor

'Usage
 
Dim instance As RasterImage
Dim value As RasterColor
 
instance.TransparentColor = value
 
value = instance.TransparentColor

public RasterColor TransparentColor {get; set;}

@property (nonatomic, copy) LTRasterColor* transparentColor;

public RasterColor getTransparentColor()
public void setTransparentColor(RasterColor value)

 
get_TransparentColor();
set_TransparentColor(value);
Object.defineProperty('TransparentColor');

public:
property RasterColor TransparentColor {
   RasterColor get();
   void set (    RasterColor value);
}

Property Value

The transparent color used when painting this image.

The TransparentColor of a RasterImage is used when the Transparent property value is set to true.

Note, transparent paint does not work with RasterPaintEngine.Gdi. For more information, refer to Leadtools.Drawing.RasterPaintProperties.

If this RasterImage has a BitsPerPixel value of 8 or less, then the image has a palette. For palettized images, the value of the TransparentColor can be an RGB value or a palette index.

To set a palette index as the transparent color, use the RasterColor.FromPaletteIndex method.

If the color passed is a true RGB value(The value of see RasterColor.IsPaletteIndex is false and the image has a palette, then this RasterImage object will call GetTrueColorValue on the TransparentColor to translate it into the nearest palette index entry before using it to determine the actual transparent color in the image when painting.

For more information, refer to PNG Files and Transparency.

C#
Visual Basic
WinRT C#
WinRT JavaScript
Silverlight C#
Silverlight VB

Copy Code

Imports Leadtools
Imports Leadtools.Codecs
Imports Leadtools.ImageProcessing
Imports Leadtools.ImageProcessing.Core
Imports Leadtools.ImageProcessing.Color
Imports Leadtools.WinForms
Imports Leadtools.Dicom
Imports Leadtools.Drawing

Public Sub TransparentColorExample()
   Dim codecs As RasterCodecs = New RasterCodecs()

   Dim srcFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Ocr1.tif")
   Dim destFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Ocr1_Transparent.gif")

   ' Load the image
   Dim image As RasterImage = codecs.Load(srcFileName)

   ' Change the image's palette to be Red and Blue
   Dim redBluePalette As RasterColor() = New RasterColor(1) {}
   redBluePalette(0) = RasterColor.FromKnownColor(RasterKnownColor.Red)
   redBluePalette(1) = RasterColor.FromKnownColor(RasterKnownColor.Blue)
   image.SetPalette(redBluePalette, 0, 2)

   ' make red the transparent color
   image.Transparent = True
   image.TransparentColor = redBluePalette(0)

   ' Save the image
   codecs.Save(image, destFileName, RasterImageFormat.Gif, 8)

   ' Now load Ocr1_Transparent.gif in Internet Explorer.
   ' Notice how red is treated as a transparent color.
   ' You should get Blue text on a white background
   '    (if IE's background color is white).

   image.Dispose()
   codecs.Dispose()
End Sub

Public NotInheritable Class LEAD_VARS
Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images"
End Class

using Leadtools;
using Leadtools.Codecs;
using Leadtools.ImageProcessing;
using Leadtools.ImageProcessing.Core;
using Leadtools.ImageProcessing.Color;
using Leadtools.WinForms;
using Leadtools.Dicom;
using Leadtools.Drawing;

      
public void TransparentColorExample()
{
   RasterCodecs codecs = new RasterCodecs();
   string srcFileName = Path.Combine(ImagesPath.Path, "Ocr1.tif");
   string destFileName = Path.Combine(ImagesPath.Path, "Ocr1_Transparent.gif");

   // Load the image
   RasterImage image = codecs.Load(srcFileName);

   // Change the image's palette to be Red and Blue
   RasterColor[] redBluePalette = new RasterColor[2];
   redBluePalette[0] = RasterColor.FromKnownColor(RasterKnownColor.Red);
   redBluePalette[1] = RasterColor.FromKnownColor(RasterKnownColor.Blue);
   image.SetPalette(redBluePalette, 0, 2);

   // make red the transparent color
   image.Transparent = true;
   image.TransparentColor = redBluePalette[0];

   // Save the image
   codecs.Save(image, destFileName, RasterImageFormat.Gif, 8);

   // Now load Ocr1_Transparent.gif in Internet Explorer.
   // Notice how red is treated as a transparent color.
   // You should get Blue text on a white background
   //    (if IE's background color is white).

   image.Dispose();
   codecs.Dispose();
}

RasterImageExamples.prototype.TransparentColorExample = function ( )
{
   Tools.SetLicense ( ) ;
   with (Leadtools) {
      with (Leadtools.Codecs) {
         var codecs = new RasterCodecs();

         var srcFileName = "Assets\\Ocr1.tif";
         var destFileName = "Ocr1_Transparent.gif";
         var image;
         // Load the image
         return Tools.AppInstallFolder().getFileAsync(srcFileName).then(function (loadFile) {
            return codecs.loadAsync(LeadStreamFactory.create(loadFile))
         })
            .then(function (img) {
               image = img;
               // Change the image's palette to be Red and Blue
               var redBluePalette = [RasterColorHelper.fromKnownColor(RasterKnownColor.Red),
                  RasterColorHelper.fromKnownColor(RasterKnownColor.Blue)];
               image.setPalette(redBluePalette, 0, 2);

               // make red the transparent color
               image.transparent = true;
               image.transparentColor = redBluePalette[0];

               // Save the image
               return Tools.AppLocalFolder().createFileAsync(destFileName)
            })
            .then(function (saveFile) {
               var saveStream = LeadStreamFactory.create (saveFile);
               return codecs.saveAsync(image, saveStream, RasterImageFormat.gif, 8)
            })
            .then(function () {

               // Now load Ocr1_Transparent.gif in Internet Explorer.
               // Notice how red is treated as a transparent color.
               // You should get Blue text on a white background
               //    (if IE's background color is white).

               image.close();
               codecs.close();
            })
      }
   }
}

using Leadtools;
using Leadtools.Codecs;
using Leadtools.ImageProcessing;
using Leadtools.ImageProcessing.Core;
using Leadtools.ImageProcessing.Color;
using Leadtools.Dicom;

      
public async Task TransparentColorExample()
{
   RasterCodecs codecs = new RasterCodecs();
   string srcFileName = @"Assets\Ocr1.tif";
   string destFileName = @"Ocr1_Transparent.gif";

   // Load the image
   StorageFile loadFile = await Tools.AppInstallFolder.GetFileAsync(srcFileName);
   RasterImage image = await codecs.LoadAsync(LeadStreamFactory.Create(loadFile));

   // Change the image's palette to be Red and Blue
   RasterColor[] redBluePalette = { RasterColorHelper.FromKnownColor(RasterKnownColor.Red),
                                    RasterColorHelper.FromKnownColor(RasterKnownColor.Blue)};
   image.SetPalette(redBluePalette, 0, 2);

   // make red the transparent color
   image.Transparent = true;
   image.TransparentColor = redBluePalette[0];

   // Save the image
   StorageFile saveFile = await Tools.AppLocalFolder.CreateFileAsync(destFileName);
   ILeadStream saveStream = LeadStreamFactory.Create(saveFile);
   await codecs.SaveAsync(image, saveStream, RasterImageFormat.Gif, 8);

   // Now load Ocr1_Transparent.gif in Internet Explorer.
   // Notice how red is treated as a transparent color.
   // You should get Blue text on a white background
   //    (if IE's background color is white).

   image.Dispose();
   codecs.Dispose();
}

using Leadtools;
using Leadtools.Codecs;
using Leadtools.Dicom;
using Leadtools.ImageProcessing;
using Leadtools.ImageProcessing.Core;
using Leadtools.ImageProcessing.Color;
using Leadtools.Examples;
using Leadtools.Windows.Media;

public void TransparentColorExample(RasterImage image, Stream destStream)
{
   // Change the image's palette to be Red and Blue
   RasterColor[] redBluePalette = new RasterColor[2];
   redBluePalette[0] = RasterColorConverter.FromColor(Colors.Red);
   redBluePalette[1] = RasterColorConverter.FromColor(Colors.Blue);
   image.SetPalette(redBluePalette, 0, 2);
   // make red the transparent color
   image.Transparent = true;
   image.TransparentColor = redBluePalette[0];

   // Save the image
   RasterCodecs codecs = new RasterCodecs();
   codecs.Save(image, destStream, RasterImageFormat.Gif, 8);

   // Now load Ocr1_Transparent.gif in Internet Explorer.
   // Notice how red is treated as a transparent color.
   // You should get Blue text on a white background
   //    (if IE's background color is white).

   image.Dispose();
}

Imports Leadtools
Imports Leadtools.Codecs
Imports Leadtools.Dicom
Imports Leadtools.ImageProcessing
Imports Leadtools.ImageProcessing.Core
Imports Leadtools.ImageProcessing.Color
Imports Leadtools.Windows.Media

Public Sub TransparentColorExample(ByVal image As RasterImage, ByVal destStream As Stream)
   ' Change the image's palette to be Red and Blue
   Dim redBluePalette As RasterColor() = New RasterColor(1){}
   redBluePalette(0) = RasterColorConverter.FromColor(Colors.Red)
   redBluePalette(1) = RasterColorConverter.FromColor(Colors.Blue)
   image.SetPalette(redBluePalette, 0, 2)
   ' make red the transparent color
   image.Transparent = True
   image.TransparentColor = redBluePalette(0)

   ' Save the image
   Dim codecs As RasterCodecs = New RasterCodecs()
   codecs.Save(image, destStream, RasterImageFormat.Gif, 8)

   ' Now load Ocr1_Transparent.gif in Internet Explorer.
   ' Notice how red is treated as a transparent color.
   ' You should get Blue text on a white background
   '    (if IE's background color is white).

   image.Dispose()
End Sub

Target Platforms

Reference

RasterImage Class
RasterImage Members