高效取图片像素的方法

public static short

[][] GetPixs(Bitmap bitmap)
{
int height = bitmap.Height;
int width = bitmap.Width;
byte tempB, tempG, tempR;
short[][] spOriginData = new short[height][];
for (int i = 0; i < height; i++)
{
spOriginData[i] = new short[width];
}

BitmapData dataOut = bitmap.LockBits(new Rectangle(0, 0, width, height), ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb);
int offset = dataOut.Stride - dataOut.Width * 3;
try
{
unsafe
{
byte* pOut = (byte*)(dataOut.Scan0.ToPointer());

for (int y = 0; y < height; y++)
{
for (int x = 0; x < width; x++)
{
tempB = pOut[0];
tempG = pOut[1];
tempR = pOut[2];
double data=0.31 * tempR + 0.59 * tempG + 0.11 * tempB;
if (data > 255)
spOriginData[y][x] = 255;
else
if (data < 0)
spOriginData[y][x] = 0;
else
spOriginData[y][x] = (short)data;
pOut += 3;
}
pOut += offset;
}
bitmap.UnlockBits(dataOut);
}
}
catch
{
}
return spOriginData;
}