protected override unsafe void ProcessFilter(UnmanagedImage image, UnmanagedImage overlay)
{
PixelFormat pixelFormat = image.PixelFormat;
int width = image.Width;
int height = image.Height;
if ((pixelFormat == PixelFormat.Format8bppIndexed) ||
(pixelFormat == PixelFormat.Format24bppRgb) ||
(pixelFormat == PixelFormat.Format32bppRgb) ||
(pixelFormat == PixelFormat.Format32bppArgb))
{
// initialize other variables
var pixelSize = (pixelFormat == PixelFormat.Format8bppIndexed) ? 1 :
(pixelFormat == PixelFormat.Format24bppRgb) ? 3 : 4;
var lineSize = width * pixelSize;
var srcOffset = image.Stride - lineSize;
var ovrOffset = overlay.Stride - lineSize;
// new pixel value
// do the job
var ptr = (byte*)image.ImageData.ToPointer();
var ovr = (byte*)overlay.ImageData.ToPointer();
// for each line
for (var y = 0; y < height; y++)
{
// for each pixel
for (var x = 0; x < lineSize; x++, ptr++, ovr++)
*ptr = (byte)((*ptr * *ovr) / 255);
ptr += srcOffset;
ovr += ovrOffset;
}
}
else
{
// initialize other variables
int pixelSize = (pixelFormat == PixelFormat.Format16bppGrayScale) ? 1 :
(pixelFormat == PixelFormat.Format48bppRgb) ? 3 : 4;
int lineSize = width * pixelSize;
int srcStride = image.Stride;
int ovrStride = overlay.Stride;
// new pixel value
// do the job
var basePtr = (byte*)image.ImageData.ToPointer();
var baseOvr = (byte*)overlay.ImageData.ToPointer();
// for each line
for (var y = 0; y < height; y++)
{
var ptr = (ushort*)(basePtr + y * srcStride);
var ovr = (ushort*)(baseOvr + y * ovrStride);
// for each pixel
for (var x = 0; x < lineSize; x++, ptr++, ovr++)
*ptr = (ushort)((*ptr * *ovr) / 65535);
}
}
}
}
