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Added "Adjust" to the ImageHelper, this can change the brightness, contrast and gamma.

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git-svn-id: http://svn.code.sf.net/p/greenshot/code/trunk@2469 7dccd23d-a4a3-4e1f-8c07-b4c1b4018ab4
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RKrom 2013-02-07 13:19:01 +00:00
parent 7573373a5d
commit a2fb7bf322
2 changed files with 63 additions and 0 deletions
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36
GreenshotPlugin/Core/ImageHelper.cs
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@ -1029,6 +1029,42 @@ namespace GreenshotPlugin.Core {
return newImage;
}
/// <summary>
/// Adjust the brightness, contract or gamma of an image.
/// Use the value "1.0f" for no changes.
/// </summary>
/// <param name="sourceImage">Original bitmap</param>
/// <returns>Bitmap with grayscale</returns>
public static Image Adjust(Image sourceImage, float brightness, float contrast, float gamma) {
//create a blank bitmap the same size as original
// If using 8bpp than the following exception comes: A Graphics object cannot be created from an image that has an indexed pixel format.
Bitmap newBitmap = CreateEmpty(sourceImage.Width, sourceImage.Height, PixelFormat.Format24bppRgb, Color.Empty, sourceImage.HorizontalResolution, sourceImage.VerticalResolution);
float adjustedBrightness = brightness - 1.0f;
// get a graphics object from the new image
using (Graphics graphics = Graphics.FromImage(newBitmap)) {
// create the grayscale ColorMatrix
ColorMatrix colorMatrix = new ColorMatrix(
new float[][] {
new float[] {contrast, 0, 0, 0, 0}, // scale red
new float[] {0, contrast, 0, 0, 0}, // scale green
new float[] {0, 0, contrast, 0, 0}, // scale blue
new float[] {0, 0, 0, 1.0f, 0}, // don't scale alpha
new float[] {adjustedBrightness, adjustedBrightness, adjustedBrightness, 0, 1}
});
//create some image attributes
ImageAttributes attributes = new ImageAttributes();
//set the color matrix attribute
attributes.SetColorMatrix(colorMatrix);
//draw the original image on the new image using the grayscale color matrix
graphics.DrawImage(sourceImage, new Rectangle(0, 0, sourceImage.Width, sourceImage.Height), 0, 0, sourceImage.Width, sourceImage.Height, GraphicsUnit.Pixel, attributes);
}
return newBitmap;
}
/// <summary>
/// Create a new bitmap where the sourceBitmap is in grayscale
/// </summary>