Win8Metro(C#)数字图像处理--2.6图像对比度调整
2.6图像对比度调整函数
[函数名称]
图像对比度调整函数ContrastAdjustProcess(WriteableBitmap src, doublecontrastValue)
[函数代码]
///<summary>
/// Contrast adjust process.
///</summary>
///<param name="src">Source image.</param>
///<param name="contrastValue">Contrast value, from -1 to 1.</param>
///<returns></returns>
publicstaticWriteableBitmap ContrastAdjustProcess(WriteableBitmap src,double contrastValue)////6对比度调整
{
if(src!=null )
{
int w = src.PixelWidth;
int h = src.PixelHeight;
WriteableBitmap contrastImage =newWriteableBitmap(w,h);
byte[] temp = src.PixelBuffer.ToArray();
for (int i = 0; i < temp.Length; i += 4)
{
temp[i] =Convert.ToByte((((temp[i] - 127.5) * contrastValue + temp[i]) > 255 ? 255 : ((temp[i] - 127.5) * contrastValue + temp[i])) < 0 ? 0 : (((temp[i] - 127.5) * contrastValue + temp[i]) > 255 ? 255 : ((temp[i] - 127.5) * contrastValue + temp[i])));
temp[i + 1] =Convert.ToByte((((temp[i + 1] - 127.5) * contrastValue + temp[i + 1]) > 255 ? 255 : ((temp[i + 1] - 127.5) * contrastValue + temp[i + 1])) < 0 ? 0 : (((temp[i + 1] - 127.5) * contrastValue + temp[i + 1]) > 255 ? 255 : ((temp[i + 1] - 127.5) * contrastValue + temp[i + 1])));
temp[i + 2] =Convert.ToByte((((temp[i + 2] - 127.5) * contrastValue + temp[i + 2]) > 255 ? 255 : ((temp[i + 2] - 127.5) * contrastValue + temp[i + 2])) < 0 ? 0 : (((temp[i + 2] - 127.5) * contrastValue + temp[i + 2]) > 255 ? 255 : ((temp[i + 2] - 127.5) * contrastValue + temp[i + 2])));
}
Stream sTemp = contrastImage.PixelBuffer.AsStream();
sTemp.Seek(0,SeekOrigin.Begin);
sTemp.Write(temp, 0, w * 4 * h);
return contrastImage;
}
else
{
returnnull;
}
}
