AForge.Imaging.Filters.LevelsLinear16bpp.ProcessFilter C# (CSharp) Method

        protected override unsafe void ProcessFilter( UnmanagedImage image, Rectangle rect )
        {
            int pixelSize = Image.GetPixelFormatSize( image.PixelFormat ) / 16;

            // processing start and stop X,Y positions
            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;

            // do the job
            byte* basePtr =(byte*) image.ImageData.ToPointer( );

            if ( image.PixelFormat == PixelFormat.Format16bppGrayScale )
            {
                // grayscale image
                for ( int y = startY; y < stopY; y++ )
                {
                    ushort* ptr = (ushort*) ( basePtr + y * image.Stride ) + startX;

                    for ( int x = startX; x < stopX; x++, ptr++ )
                    {
                        // gray
                        *ptr = mapGreen[*ptr];
                    }
                }
            }
            else
            {
                // RGB image
                for ( int y = startY; y < stopY; y++ )
                {
                    ushort* ptr = (ushort*) ( basePtr + y * image.Stride ) + startX * pixelSize;

                    for ( int x = startX; x < stopX; x++, ptr += pixelSize )
                    {
                        // red
                        ptr[RGB.R] = mapRed[ptr[RGB.R]];
                        // green
                        ptr[RGB.G] = mapGreen[ptr[RGB.G]];
                        // blue
                        ptr[RGB.B] = mapBlue[ptr[RGB.B]];
                    }
                }
            }
        }