static public Bitmap AdjustSharpness(Bitmap srcImg, float level)
{
Bitmap dstImg = new Bitmap(srcImg);
BitmapData srcDat = srcImg.LockBits(
new Rectangle(0, 0, srcImg.Width, srcImg.Height),
ImageLockMode.ReadWrite,
PixelFormat.Format32bppArgb);
byte[] srcBuf = new byte[srcImg.Width * srcImg.Height * 4];
Marshal.Copy(srcDat.Scan0, srcBuf, 0, srcBuf.Length);
BitmapData dstDat = dstImg.LockBits(
new Rectangle(0, 0, dstImg.Width, dstImg.Height),
ImageLockMode.ReadWrite,
PixelFormat.Format32bppArgb);
byte[] dstBuf = new byte[dstImg.Width * dstImg.Height * 4];
Marshal.Copy(dstDat.Scan0, dstBuf, 0, dstBuf.Length);
for (int i = 1; i < srcImg.Height - 1; i++) {
int dy1 = (i - 1) * (srcImg.Width * 4);
int dy = i * (srcImg.Width * 4);
int dy2 = (i + 1) * (srcImg.Width * 4);
for (int j = 1; j < srcImg.Width - 1; j++)
{
int dx1 = (j - 1) * 4;
int dx = j * 4;
int dx2 = (j + 1) * 4;
for (int k = 0; k < 3; k++)
{
int value = (int)((float)srcBuf[dy + dx + k] * (1f + level * 4))
- (int)((float)srcBuf[dy1 + dx + k] * level)
- (int)((float)srcBuf[dy + dx1 + k] * level)
- (int)((float)srcBuf[dy + dx2 + k] * level)
- (int)((float)srcBuf[dy2 + dx + k] * level);
value = Math.Min(value, 255);
value = Math.Max(value, 0);
dstBuf[dy + dx + k] = (byte)value;
}
}
}
Marshal.Copy(dstBuf, 0, dstDat.Scan0, dstBuf.Length);
dstImg.UnlockBits(dstDat);
srcImg.UnlockBits(srcDat);
return dstImg;
}
