在.NET中,有什么简单的方法可以调整图像的亮度、对比度和伽马值?
Bitmap originalImage;
Bitmap adjustedImage;
float brightness = 1.0f; // no change in brightness
float contrast = 2.0f; // twice the contrast
float gamma = 1.0f; // no change in gamma
float adjustedBrightness = brightness - 1.0f;
// create matrix that will brighten and contrast the image
float[][] ptsArray ={
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}};
ImageAttributes imageAttributes = new ImageAttributes();
imageAttributes.ClearColorMatrix();
imageAttributes.SetColorMatrix(new ColorMatrix(ptsArray), ColorMatrixFlag.Default, ColorAdjustType.Bitmap);
imageAttributes.SetGamma(gamma, ColorAdjustType.Bitmap);
Graphics g = Graphics.FromImage(adjustedImage);
g.DrawImage(originalImage, new Rectangle(0,0,adjustedImage.Width,adjustedImage.Height)
,0,0,originalImage.Width,originalImage.Height,
GraphicsUnit.Pixel, imageAttributes);
Bitmap originalImage = (Bitmap)myPictureBox.Image; // my application has a Winform with a PictureBox to display an image and is defined outside of this code block.
Bitmap adjustedImage = new Bitmap(myPictureBox.Image.Width, myPictureBox.Image.Height); // Created an instance of Bitmap with the same dimensions as myOriginalImage
float brightness = 1.0f; // no change in brightness
float contrast = 2.0f; // twice the contrast
float gamma = 1.0f; // no change in gamma
float adjustedBrightness = brightness - 1.0f;
// create matrix that will brighten and contrast the image
float[][] ptsArray ={
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}};
ImageAttributes imageAttributes = new ImageAttributes();
imageAttributes.ClearColorMatrix();
imageAttributes.SetColorMatrix(new ColorMatrix(ptsArray),
ColorMatrixFlag.Default, ColorAdjustType.Bitmap);
imageAttributes.SetGamma(gamma, ColorAdjustType.Bitmap);
Graphics g = Graphics.FromImage(adjustedImage);
g.DrawImage(originalImage, new Rectangle(0,0,adjustedImage.Width,adjustedImage.Height),0,0,originalImage.Width,originalImage.Height,GraphicsUnit.Pixel, imageAttributes);
// Now display the adjusted image in Winform PictureBox
myPictureBox.Image = adjustedImage;
this.Refresh();