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

        protected override unsafe void ProcessFilter( UnmanagedImage image, Rectangle rect )
        {
            int startX  = rect.Left;
            int startY  = rect.Top;
            int stopX   = startX + rect.Width;
            int stopY   = startY + rect.Height;
            int offset  = image.Stride - rect.Width;

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

            // allign pointer to the first pixel to process
            ptr += ( startY * image.Stride + startX );

            // for each line	
            for ( int y = startY; y < stopY; y++ )
            {
                // for each pixel
                for ( int x = startX; x < stopX; x++, ptr++ )
                {
                    *ptr = (byte) ( ( *ptr <= matrix[( y % rows ), ( x % cols )] ) ? 0 : 255 );
                }
                ptr += offset;
            }
        }
    }