コード例 #1
0
ファイル: OrderedDither.cs プロジェクト: mbrdev/ImageSharp
        public OrderedDither(uint length)
        {
            Guard.MustBeGreaterThan(length, 0, nameof(length));

            DenseMatrix <uint> ditherMatrix = OrderedDitherFactory.CreateDitherMatrix(length);

            // Create a new matrix to run against, that pre-thresholds the values.
            // We don't want to adjust the original matrix generation code as that
            // creates known, easy to test values.
            // https://en.wikipedia.org/wiki/Ordered_dithering#Algorithm
            var   thresholdMatrix = new DenseMatrix <float>((int)length);
            float m2 = length * length;

            for (int y = 0; y < length; y++)
            {
                for (int x = 0; x < length; x++)
                {
                    thresholdMatrix[y, x] = ((ditherMatrix[y, x] + 1) / m2) - .5F;
                }
            }

            this.modulusX        = ditherMatrix.Columns;
            this.modulusY        = ditherMatrix.Rows;
            this.thresholdMatrix = thresholdMatrix;
        }
コード例 #2
0
        /// <summary>
        /// Initializes a new instance of the <see cref="OrderedDither"/> class.
        /// </summary>
        /// <param name="length">The length of the matrix sides</param>
        public OrderedDither(uint length)
        {
            DenseMatrix <uint> ditherMatrix = OrderedDitherFactory.CreateDitherMatrix(length);

            this.modulusX = ditherMatrix.Columns;
            this.modulusY = ditherMatrix.Rows;

            // Adjust the matrix range for 0-255
            // TODO: It looks like it's actually possible to dither an image using it's own colors. We should investigate for V2
            // https://stackoverflow.com/questions/12422407/monochrome-dithering-in-javascript-bayer-atkinson-floyd-steinberg
            int multiplier = 256 / ditherMatrix.Count;

            for (int y = 0; y < ditherMatrix.Rows; y++)
            {
                for (int x = 0; x < ditherMatrix.Columns; x++)
                {
                    ditherMatrix[y, x] = (uint)((ditherMatrix[y, x] + 1) * multiplier) - 1;
                }
            }

            this.thresholdMatrix = ditherMatrix;
        }