/// <summary>
        /// Rectification filter for projective transformation.
        /// <para>Accord.NET internal call. Please see: <see cref="Accord.Imaging.Filters.Rectification"/> for details.</para>
        /// </summary>
        /// <param name="img">Image.</param>
        /// <param name="homography">The homography matrix used to map a image passed to the filter to the overlay image.</param>
        /// <param name="fillColor">The filling color used to fill blank spaces.</param>
        /// <returns>Rectified image.</returns>
        public static Gray<byte>[,] Rectification(this Gray<byte>[,] img, double[,] homography, Gray<byte> fillColor) 
            Rectification r = new Rectification(homography);
            r.FillColor = fillColor.ToColor();

            return img.ApplyBaseTransformationFilter(r);
Example #2
        /// <summary>
        /// The blending filter is able to blend two images using a homography matrix.
        /// A linear alpha gradient is used to smooth out differences between the two
        /// images, effectively blending them in two images. The gradient is computed
        /// considering the distance between the centers of the two images.
        /// </summary>
        /// <param name="im">Image.</param>
        /// <param name="overlayIm">The overlay image (also called the anchor).</param>
        /// <param name="homography">Homography matrix used to map a image passed to
        /// the filter to the overlay image specified at filter creation.</param>
        /// <param name="fillColor">The filling color used to fill blank spaces. The filling color will only be visible after the image is converted
        /// to 24bpp. The alpha channel will be used internally by the filter.</param>
        /// <param name="gradient">A value indicating whether to blend using a linear
        ///  gradient or just superimpose the two images with equal weights.</param>
        /// <param name="alphaOnly">A value indicating whether only the alpha channel
        /// should be blended. This can be used together with a transparency
        /// mask to selectively blend only portions of the image.</param>
        /// <returns>Blended image.</returns>
        public static Bgra<byte>[,] Blend(this Gray<byte>[,] im, Gray<byte>[,] overlayIm, MatrixH homography, Bgra<byte> fillColor, bool gradient = true, bool alphaOnly = false)
            Bgra<byte>[,] resultImage = null;

            using (var uOverlayIm = overlayIm.Lock())
                Blend blend = new Blend(homography, uOverlayIm.AsBitmap());
                blend.AlphaOnly = alphaOnly;
                blend.Gradient = gradient;
                blend.FillColor = fillColor.ToColor();

                resultImage = im.ApplyBaseTransformationFilter<Gray<byte>, Bgra<byte>>(blend);

            return resultImage;