Gets the true (RGB) value of the specified color based on the current image palette.
public Leadtools.RasterColor GetTrueColorValue(
Leadtools.RasterColor color
)
Public Function GetTrueColorValue( _
ByVal color As Leadtools.RasterColor _
) As Leadtools.RasterColor
public Leadtools.RasterColor GetTrueColorValue(
Leadtools.RasterColor color
)
- (LTRasterColor *)getTrueColorValue:(LTRasterColor *)color
public RasterColor getTrueColorValue(RasterColor color)
function Leadtools.RasterImage.GetTrueColorValue(
color
)
public:
Leadtools.RasterColor GetTrueColorValue(
Leadtools.RasterColor color
)
color
a RasterColor that specifies the source color
A RasterColor that is guaranteed to be a true color (has RGB value)
Use this method to translate a color that is really a palette index (the value of the RasterColor.IsPaletteIndex property is true) to a true RGB color value
The apposite of this method is TranslateColor.
This example will create transparent GIF file
using Leadtools;
using Leadtools.Codecs;
using Leadtools.ImageProcessing;
using Leadtools.Drawing;
using LeadtoolsExamples.Common;
public void CreateTransparentGifExample()
{
// Create a 24 bpp image, we will draw on it first then convert it to 8 bpp
using (RasterImage image = new RasterImage(
RasterMemoryFlags.Conventional,
256,
256,
8,
RasterByteOrder.Bgr,
RasterViewPerspective.BottomLeft,
null,
IntPtr.Zero,
0))
{
Assert.IsNotNull(image);
// Fill the image with the transparent color.
RasterColor transparentColor = RasterColor.FromKnownColor(RasterKnownColor.Magenta);
new FillCommand(transparentColor).Run(image);
image.Transparent = true;
// Get the true color used for Magenta inside this image (a palette index)
image.TransparentColor = image.TranslateColor(image, transparentColor);
// Draw on the image, else the entire image will be transparent.
DrawEllipses(image);
// Save this image as GIF
string fileName = Path.Combine(ImagesPath.Path, "TransparentEllipses.gif");
using (RasterCodecs codecs = new RasterCodecs())
{
codecs.Save(image, fileName, RasterImageFormat.Gif, 8);
}
}
}
void DrawEllipses(RasterImage image)
{
// Fill this image with magenta color and draw some random ellipses on top
const int ellipseWidth = 40;
const int ellipseHeight = 40;
IntPtr hdc = IntPtr.Zero;
try
{
hdc = RasterImagePainter.CreateLeadDC(image);
Assert.IsFalse(hdc == IntPtr.Zero);
using (Graphics g = Graphics.FromHdc(hdc))
{
Assert.IsNotNull(g);
Random r = new Random();
for (int i = 0; i < 40; i++)
{
int x = r.Next(image.Width - ellipseWidth);
int y = r.Next(image.Height - ellipseHeight);
Color clr = Color.FromArgb(r.Next(256), r.Next(256), r.Next(256));
using (Brush brush = new SolidBrush(clr))
{
g.FillEllipse(brush, x, y, ellipseWidth, ellipseHeight);
}
}
}
}
finally
{
// Make sure to delete the handle to the DC.
if (hdc != IntPtr.Zero)
RasterImagePainter.DeleteLeadDC(hdc);
}
}
Imports Leadtools
Imports Leadtools.Codecs
Imports Leadtools.ImageProcessing
Imports Leadtools.Drawing
Public Sub CreateTransparentGifExample()
' Create a 24 bpp image, we will draw on it first then convert it to 8 bpp
Dim imageWidth As Integer = 256
Dim imageHeight As Integer = 256
Dim image As New RasterImage(
RasterMemoryFlags.Conventional,
imageWidth,
imageHeight,
24,
RasterByteOrder.Bgr,
RasterViewPerspective.BottomLeft,
Nothing,
IntPtr.Zero,
0)
' Fill this image with magenta color and draw some random ellipses on top
Dim hdc As IntPtr = RasterImagePainter.CreateLeadDC(image)
Dim g As Graphics = Graphics.FromHdc(hdc)
g.FillRectangle(Brushes.Magenta, 0, 0, imageWidth, imageHeight)
Const ellipseWidth As Integer = 40
Const ellipseHeight As Integer = 40
Dim r As New Random()
For i As Integer = 0 To 39
Dim x As Integer = r.Next(imageWidth - ellipseWidth)
Dim y As Integer = r.Next(imageHeight - ellipseHeight)
Dim clr As Color = Color.FromArgb(r.Next(256), r.Next(256), r.Next(256))
Dim brush As New SolidBrush(clr)
g.FillEllipse(brush, x, y, ellipseWidth, ellipseHeight)
brush.Dispose()
Next
g.Dispose()
RasterImagePainter.DeleteLeadDC(hdc)
' Convert this image to 8 bits/pixel
Dim cmd As New ColorResolutionCommand(
ColorResolutionCommandMode.InPlace,
8,
RasterByteOrder.Rgb,
RasterDitheringMethod.None,
ColorResolutionCommandPaletteFlags.Optimized,
Nothing)
cmd.Run(image)
' Find the Magenta color and set it as the transparent color
Dim transparentColor As RasterColor = RasterColor.FromKnownColor(RasterKnownColor.Magenta)
' Get the true color used for Magenta inside this image (a palette index)
transparentColor = image.TranslateColor(image, transparentColor)
image.Transparent = True
image.TransparentColor = transparentColor
' Initialize the RasterCodecs object
Dim codecs As New RasterCodecs()
' Save this image as GIF
Dim fileName As String = Path.Combine(LEAD_VARS.ImagesDir, "TransparentEllipses.gif")
codecs.Save(image, fileName, RasterImageFormat.Gif, 8)
' Clean up
image.Dispose()
codecs.Dispose()
End Sub
Public NotInheritable Class LEAD_VARS
Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images"
End Class
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