protected unsafe override void ProcessFilter(UnmanagedImage image, Rectangle rect)
{
int pixelSize = Bitmap.GetPixelFormatSize(image.PixelFormat) / 8;
int startX = rect.Left;
int startY = rect.Top;
int stopX = startX + rect.Width;
int stopY = startY + rect.Height;
int offset = image.Stride - rect.Width * pixelSize;
bool exclude = false;
RGB rgb = new RGB();
HSL hsl = new HSL();
// do the job
byte* ptr = (byte*)image.ImageData.ToPointer();
// allign pointer to the first pixel to process
ptr += (startY * image.Stride + startX * pixelSize);
// for each row
for (int y = startY; y < stopY; y++)
{
// for each pixel
for (int x = startX; x < stopX; x++, ptr += pixelSize)
{
rgb.Red = ptr[RGB.R];
rgb.Green = ptr[RGB.G];
rgb.Blue = ptr[RGB.B];
exclude = false;
if (keepBW)
{
if (rgb.Red == 0 && rgb.Green == 0 && rgb.Blue == 0)
exclude = true;
if (rgb.Red == 255 && rgb.Green == 255 && rgb.Blue == 255)
exclude = true;
}
if(!exclude)
{
// convert to HSL
AForge.Imaging.HSL.FromRGB(rgb, hsl);
// modify hue value
hsl.Hue += hue;
// convert back to RGB
AForge.Imaging.HSL.ToRGB(hsl, rgb);
ptr[RGB.R] = rgb.Red;
ptr[RGB.G] = rgb.Green;
ptr[RGB.B] = rgb.Blue;
}
}
ptr += offset;
}
}