Accord.Imaging.Filters.TexturedMerge.ProcessFilter C# (CSharp) Method

        protected override unsafe void ProcessFilter(UnmanagedImage image, UnmanagedImage overlay)
        {
            // get image dimension
            int width = image.Width;
            int height = image.Height;

            // width and height to process
            int widthToProcess = width;
            int heightToProcess = height;

            // if generator was specified, then generate a texture
            // otherwise use provided texture
            if (textureGenerator != null)
            {
                texture = textureGenerator.Generate(width, height);
            }
            else
            {
                widthToProcess = Math.Min(width, texture.GetLength(1));
                heightToProcess = Math.Min(height, texture.GetLength(0));
            }

            int pixelSize = Image.GetPixelFormatSize(image.PixelFormat) / 8;
            int srcOffset = image.Stride - widthToProcess * pixelSize;
            int ovrOffset = overlay.Stride - widthToProcess * pixelSize;

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

            // for each line
            for (int y = 0; y < heightToProcess; y++)
            {
                // for each pixel
                for (int x = 0; x < widthToProcess; x++)
                {
                    double t1 = texture[y, x];
                    double t2 = 1 - t1;

                    for (int i = 0; i < pixelSize; i++, ptr++, ovr++)
                    {
                        *ptr = (byte)Math.Min(255.0f, *ptr * t1 + *ovr * t2);
                    }
                }
                ptr += srcOffset;
                ovr += ovrOffset;
            }
        }
    }