mirror of
https://github.com/greenshot/greenshot
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f19f3d6e63
git-svn-id: http://svn.code.sf.net/p/greenshot/code/trunk@1716 7dccd23d-a4a3-4e1f-8c07-b4c1b4018ab4
686 lines
No EOL
23 KiB
C#
686 lines
No EOL
23 KiB
C#
/*
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* Greenshot - a free and open source screenshot tool
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* Copyright (C) 2007-2012 Thomas Braun, Jens Klingen, Robin Krom
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*
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* For more information see: http://getgreenshot.org/
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* The Greenshot project is hosted on Sourceforge: http://sourceforge.net/projects/greenshot/
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 1 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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using System;
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using System.Collections;
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using System.Drawing;
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using System.Drawing.Imaging;
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using System.Collections.Generic;
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namespace GreenshotPlugin.Core {
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/// <summary>
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/// This interface provides a color quantization capabilities.
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/// </summary>
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public interface IColorQuantizer {
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/// <summary>
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/// Prepares the quantizer for image processing.
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/// </summary>
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/// <param name="image">The image.</param>
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void Prepare(Image image);
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/// <summary>
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/// Adds the color to quantizer.
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/// </summary>
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/// <param name="color">The color to be added.</param>
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void AddColor(Color color);
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/// <summary>
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/// Gets the palette with specified count of the colors.
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/// </summary>
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/// <param name="colorCount">The color count.</param>
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/// <returns></returns>
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List<Color> GetPalette(Int32 colorCount);
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/// <summary>
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/// Gets the index of the palette for specific color.
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/// </summary>
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/// <param name="color">The color.</param>
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/// <returns></returns>
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Int32 GetPaletteIndex(Color color);
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/// <summary>
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/// Gets the color count.
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/// </summary>
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/// <returns></returns>
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Int32 GetColorCount();
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}
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internal class WuColorCube {
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/// <summary>
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/// Gets or sets the red minimum.
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/// </summary>
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/// <value>The red minimum.</value>
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public Int32 RedMinimum { get; set; }
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/// <summary>
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/// Gets or sets the red maximum.
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/// </summary>
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/// <value>The red maximum.</value>
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public Int32 RedMaximum { get; set; }
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/// <summary>
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/// Gets or sets the green minimum.
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/// </summary>
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/// <value>The green minimum.</value>
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public Int32 GreenMinimum { get; set; }
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/// <summary>
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/// Gets or sets the green maximum.
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/// </summary>
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/// <value>The green maximum.</value>
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public Int32 GreenMaximum { get; set; }
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/// <summary>
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/// Gets or sets the blue minimum.
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/// </summary>
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/// <value>The blue minimum.</value>
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public Int32 BlueMinimum { get; set; }
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/// <summary>
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/// Gets or sets the blue maximum.
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/// </summary>
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/// <value>The blue maximum.</value>
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public Int32 BlueMaximum { get; set; }
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/// <summary>
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/// Gets or sets the cube volume.
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/// </summary>
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/// <value>The volume.</value>
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public Int32 Volume { get; set; }
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}
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public class QuantizationHelper {
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private static readonly Color BackgroundColor;
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private static readonly Double[] Factors;
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static QuantizationHelper() {
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BackgroundColor = Color.White;
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Factors = PrecalculateFactors();
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}
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/// <summary>
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/// Precalculates the alpha-fix values for all the possible alpha values (0-255).
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/// </summary>
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private static Double[] PrecalculateFactors() {
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Double[] result = new Double[256];
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for (Int32 value = 0; value < 256; value++) {
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result[value] = value / 255.0;
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}
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return result;
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}
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/// <summary>
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/// Converts the alpha blended color to a non-alpha blended color.
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/// </summary>
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/// <param name="color">The alpha blended color (ARGB).</param>
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/// <returns>The non-alpha blended color (RGB).</returns>
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internal static Color ConvertAlpha(Color color) {
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Color result = color;
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if (color.A < 255) {
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// performs a alpha blending (second color is BackgroundColor, by default a Control color)
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Double colorFactor = Factors[color.A];
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Double backgroundFactor = Factors[255 - color.A];
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Int32 red = (Int32)(color.R * colorFactor + BackgroundColor.R * backgroundFactor);
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Int32 green = (Int32)(color.G * colorFactor + BackgroundColor.G * backgroundFactor);
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Int32 blue = (Int32)(color.B * colorFactor + BackgroundColor.B * backgroundFactor);
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Int32 argb = 255 << 24 | red << 16 | green << 8 | blue;
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result = Color.FromArgb(argb);
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}
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return result;
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}
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}
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/// <summary>
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/// Author: Xiaolin Wu
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/// Dept. of Computer Science
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/// Univ. of Western Ontario
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/// London, Ontario N6A 5B7
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/// wu@csd.uwo.ca
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/// </summary>
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public class WuColorQuantizer : IColorQuantizer {
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#region | Constants |
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private const Int32 MaxColor = 512;
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private const Int32 Red = 2;
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private const Int32 Green = 1;
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private const Int32 Blue = 0;
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private const Int32 SideSize = 33;
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private const Int32 MaxSideIndex = 32;
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private const Int32 MaxVolume = SideSize * SideSize * SideSize;
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#endregion
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#region | Fields |
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BitArray bitArray;
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private Int32[] reds;
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private Int32[] greens;
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private Int32[] blues;
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private Int32[] sums;
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private Int32[] indices;
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private Int64[, ,] weights;
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private Int64[, ,] momentsRed;
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private Int64[, ,] momentsGreen;
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private Int64[, ,] momentsBlue;
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private Single[, ,] moments;
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private Int32[] tag;
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private Int32[] quantizedPixels;
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private Int32[] table;
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private Color[] pixels;
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private Int32 imageSize;
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private Int32 pixelIndex;
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private WuColorCube[] cubes;
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#endregion
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#region | Helper methods |
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/// <summary>
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/// Converts the histogram to a series of moments.
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/// </summary>
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private void CalculateMoments() {
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Int64[] area = new Int64[SideSize];
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Int64[] areaRed = new Int64[SideSize];
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Int64[] areaGreen = new Int64[SideSize];
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Int64[] areaBlue = new Int64[SideSize];
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Single[] area2 = new Single[SideSize];
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for (Int32 redIndex = 1; redIndex <= MaxSideIndex; ++redIndex) {
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for (Int32 index = 0; index <= MaxSideIndex; ++index) {
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area[index] = 0;
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areaRed[index] = 0;
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areaGreen[index] = 0;
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areaBlue[index] = 0;
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area2[index] = 0;
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}
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for (Int32 greenIndex = 1; greenIndex <= MaxSideIndex; ++greenIndex) {
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Int64 line = 0;
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Int64 lineRed = 0;
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Int64 lineGreen = 0;
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Int64 lineBlue = 0;
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Single line2 = 0.0f;
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for (Int32 blueIndex = 1; blueIndex <= MaxSideIndex; ++blueIndex) {
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line += weights[redIndex, greenIndex, blueIndex];
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lineRed += momentsRed[redIndex, greenIndex, blueIndex];
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lineGreen += momentsGreen[redIndex, greenIndex, blueIndex];
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lineBlue += momentsBlue[redIndex, greenIndex, blueIndex];
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line2 += moments[redIndex, greenIndex, blueIndex];
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area[blueIndex] += line;
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areaRed[blueIndex] += lineRed;
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areaGreen[blueIndex] += lineGreen;
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areaBlue[blueIndex] += lineBlue;
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area2[blueIndex] += line2;
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weights[redIndex, greenIndex, blueIndex] = weights[redIndex - 1, greenIndex, blueIndex] + area[blueIndex];
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momentsRed[redIndex, greenIndex, blueIndex] = momentsRed[redIndex - 1, greenIndex, blueIndex] + areaRed[blueIndex];
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momentsGreen[redIndex, greenIndex, blueIndex] = momentsGreen[redIndex - 1, greenIndex, blueIndex] + areaGreen[blueIndex];
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momentsBlue[redIndex, greenIndex, blueIndex] = momentsBlue[redIndex - 1, greenIndex, blueIndex] + areaBlue[blueIndex];
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moments[redIndex, greenIndex, blueIndex] = moments[redIndex - 1, greenIndex, blueIndex] + area2[blueIndex];
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}
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}
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}
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}
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/// <summary>
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/// Computes the volume of the cube in a specific moment.
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/// </summary>
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private static Int64 Volume(WuColorCube cube, Int64[, ,] moment) {
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return moment[cube.RedMaximum, cube.GreenMaximum, cube.BlueMaximum] -
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moment[cube.RedMaximum, cube.GreenMaximum, cube.BlueMinimum] -
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moment[cube.RedMaximum, cube.GreenMinimum, cube.BlueMaximum] +
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moment[cube.RedMaximum, cube.GreenMinimum, cube.BlueMinimum] -
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moment[cube.RedMinimum, cube.GreenMaximum, cube.BlueMaximum] +
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moment[cube.RedMinimum, cube.GreenMaximum, cube.BlueMinimum] +
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moment[cube.RedMinimum, cube.GreenMinimum, cube.BlueMaximum] -
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moment[cube.RedMinimum, cube.GreenMinimum, cube.BlueMinimum];
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}
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/// <summary>
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/// Computes the volume of the cube in a specific moment. For the floating-point values.
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/// </summary>
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private static Single VolumeFloat(WuColorCube cube, Single[, ,] moment) {
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return moment[cube.RedMaximum, cube.GreenMaximum, cube.BlueMaximum] -
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moment[cube.RedMaximum, cube.GreenMaximum, cube.BlueMinimum] -
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moment[cube.RedMaximum, cube.GreenMinimum, cube.BlueMaximum] +
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moment[cube.RedMaximum, cube.GreenMinimum, cube.BlueMinimum] -
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moment[cube.RedMinimum, cube.GreenMaximum, cube.BlueMaximum] +
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moment[cube.RedMinimum, cube.GreenMaximum, cube.BlueMinimum] +
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moment[cube.RedMinimum, cube.GreenMinimum, cube.BlueMaximum] -
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moment[cube.RedMinimum, cube.GreenMinimum, cube.BlueMinimum];
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}
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/// <summary>
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/// Splits the cube in given position, and color direction.
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/// </summary>
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private static Int64 Top(WuColorCube cube, Int32 direction, Int32 position, Int64[, ,] moment) {
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switch (direction) {
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case Red:
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return (moment[position, cube.GreenMaximum, cube.BlueMaximum] -
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moment[position, cube.GreenMaximum, cube.BlueMinimum] -
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moment[position, cube.GreenMinimum, cube.BlueMaximum] +
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moment[position, cube.GreenMinimum, cube.BlueMinimum]);
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case Green:
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return (moment[cube.RedMaximum, position, cube.BlueMaximum] -
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moment[cube.RedMaximum, position, cube.BlueMinimum] -
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moment[cube.RedMinimum, position, cube.BlueMaximum] +
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moment[cube.RedMinimum, position, cube.BlueMinimum]);
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case Blue:
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return (moment[cube.RedMaximum, cube.GreenMaximum, position] -
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moment[cube.RedMaximum, cube.GreenMinimum, position] -
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moment[cube.RedMinimum, cube.GreenMaximum, position] +
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moment[cube.RedMinimum, cube.GreenMinimum, position]);
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default:
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return 0;
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}
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}
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/// <summary>
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/// Splits the cube in a given color direction at its minimum.
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/// </summary>
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private static Int64 Bottom(WuColorCube cube, Int32 direction, Int64[, ,] moment) {
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switch (direction) {
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case Red:
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return (-moment[cube.RedMinimum, cube.GreenMaximum, cube.BlueMaximum] +
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moment[cube.RedMinimum, cube.GreenMaximum, cube.BlueMinimum] +
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moment[cube.RedMinimum, cube.GreenMinimum, cube.BlueMaximum] -
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moment[cube.RedMinimum, cube.GreenMinimum, cube.BlueMinimum]);
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case Green:
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return (-moment[cube.RedMaximum, cube.GreenMinimum, cube.BlueMaximum] +
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moment[cube.RedMaximum, cube.GreenMinimum, cube.BlueMinimum] +
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moment[cube.RedMinimum, cube.GreenMinimum, cube.BlueMaximum] -
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moment[cube.RedMinimum, cube.GreenMinimum, cube.BlueMinimum]);
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case Blue:
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return (-moment[cube.RedMaximum, cube.GreenMaximum, cube.BlueMinimum] +
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moment[cube.RedMaximum, cube.GreenMinimum, cube.BlueMinimum] +
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moment[cube.RedMinimum, cube.GreenMaximum, cube.BlueMinimum] -
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moment[cube.RedMinimum, cube.GreenMinimum, cube.BlueMinimum]);
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default:
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return 0;
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}
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}
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/// <summary>
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/// Calculates statistical variance for a given cube.
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/// </summary>
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private Single CalculateVariance(WuColorCube cube) {
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Single volumeRed = Volume(cube, momentsRed);
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Single volumeGreen = Volume(cube, momentsGreen);
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Single volumeBlue = Volume(cube, momentsBlue);
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Single volumeMoment = VolumeFloat(cube, moments);
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Single volumeWeight = Volume(cube, weights);
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Single distance = volumeRed * volumeRed + volumeGreen * volumeGreen + volumeBlue * volumeBlue;
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return volumeMoment - (distance / volumeWeight);
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}
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/// <summary>
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/// Finds the optimal (maximal) position for the cut.
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/// </summary>
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private Single Maximize(WuColorCube cube, Int32 direction, Int32 first, Int32 last, Int32[] cut, Int64 wholeRed, Int64 wholeGreen, Int64 wholeBlue, Int64 wholeWeight) {
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Int64 bottomRed = Bottom(cube, direction, momentsRed);
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Int64 bottomGreen = Bottom(cube, direction, momentsGreen);
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Int64 bottomBlue = Bottom(cube, direction, momentsBlue);
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Int64 bottomWeight = Bottom(cube, direction, weights);
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Single result = 0.0f;
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cut[0] = -1;
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for (Int32 position = first; position < last; ++position) {
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// determines the cube cut at a certain position
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Int64 halfRed = bottomRed + Top(cube, direction, position, momentsRed);
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Int64 halfGreen = bottomGreen + Top(cube, direction, position, momentsGreen);
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Int64 halfBlue = bottomBlue + Top(cube, direction, position, momentsBlue);
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Int64 halfWeight = bottomWeight + Top(cube, direction, position, weights);
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// the cube cannot be cut at bottom (this would lead to empty cube)
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if (halfWeight != 0) {
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Single halfDistance = halfRed * halfRed + halfGreen * halfGreen + halfBlue * halfBlue;
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Single temp = halfDistance / halfWeight;
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halfRed = wholeRed - halfRed;
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halfGreen = wholeGreen - halfGreen;
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halfBlue = wholeBlue - halfBlue;
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halfWeight = wholeWeight - halfWeight;
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if (halfWeight != 0) {
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halfDistance = halfRed * halfRed + halfGreen * halfGreen + halfBlue * halfBlue;
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temp += halfDistance / halfWeight;
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if (temp > result) {
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result = temp;
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cut[0] = position;
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}
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}
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}
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}
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return result;
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}
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/// <summary>
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/// Cuts a cube with another one.
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/// </summary>
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private Boolean Cut(WuColorCube first, WuColorCube second) {
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Int32 direction;
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Int32[] cutRed = { 0 };
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Int32[] cutGreen = { 0 };
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Int32[] cutBlue = { 0 };
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Int64 wholeRed = Volume(first, momentsRed);
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Int64 wholeGreen = Volume(first, momentsGreen);
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Int64 wholeBlue = Volume(first, momentsBlue);
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Int64 wholeWeight = Volume(first, weights);
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Single maxRed = Maximize(first, Red, first.RedMinimum + 1, first.RedMaximum, cutRed, wholeRed, wholeGreen, wholeBlue, wholeWeight);
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Single maxGreen = Maximize(first, Green, first.GreenMinimum + 1, first.GreenMaximum, cutGreen, wholeRed, wholeGreen, wholeBlue, wholeWeight);
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Single maxBlue = Maximize(first, Blue, first.BlueMinimum + 1, first.BlueMaximum, cutBlue, wholeRed, wholeGreen, wholeBlue, wholeWeight);
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if ((maxRed >= maxGreen) && (maxRed >= maxBlue)) {
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direction = Red;
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// cannot split empty cube
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if (cutRed[0] < 0) return false;
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} else {
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if ((maxGreen >= maxRed) && (maxGreen >= maxBlue)) {
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direction = Green;
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} else {
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direction = Blue;
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}
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}
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second.RedMaximum = first.RedMaximum;
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second.GreenMaximum = first.GreenMaximum;
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second.BlueMaximum = first.BlueMaximum;
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// cuts in a certain direction
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switch (direction) {
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case Red:
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second.RedMinimum = first.RedMaximum = cutRed[0];
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second.GreenMinimum = first.GreenMinimum;
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second.BlueMinimum = first.BlueMinimum;
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break;
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case Green:
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second.GreenMinimum = first.GreenMaximum = cutGreen[0];
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second.RedMinimum = first.RedMinimum;
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second.BlueMinimum = first.BlueMinimum;
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break;
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case Blue:
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second.BlueMinimum = first.BlueMaximum = cutBlue[0];
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second.RedMinimum = first.RedMinimum;
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second.GreenMinimum = first.GreenMinimum;
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break;
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}
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// determines the volumes after cut
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first.Volume = (first.RedMaximum - first.RedMinimum) * (first.GreenMaximum - first.GreenMinimum) * (first.BlueMaximum - first.BlueMinimum);
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second.Volume = (second.RedMaximum - second.RedMinimum) * (second.GreenMaximum - second.GreenMinimum) * (second.BlueMaximum - second.BlueMinimum);
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// the cut was successfull
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return true;
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}
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/// <summary>
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/// Marks all the tags with a given label.
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/// </summary>
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private void Mark(WuColorCube cube, Int32 label, Int32[] tag) {
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for (Int32 redIndex = cube.RedMinimum + 1; redIndex <= cube.RedMaximum; ++redIndex) {
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for (Int32 greenIndex = cube.GreenMinimum + 1; greenIndex <= cube.GreenMaximum; ++greenIndex) {
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for (Int32 blueIndex = cube.BlueMinimum + 1; blueIndex <= cube.BlueMaximum; ++blueIndex) {
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tag[(redIndex << 10) + (redIndex << 6) + redIndex + (greenIndex << 5) + greenIndex + blueIndex] = label;
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}
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}
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}
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}
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#endregion
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#region << IColorQuantizer >>
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/// <summary>
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/// See <see cref="IColorQuantizer.Prepare"/> for more details.
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/// </summary>
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public void Prepare(Image image) {
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bitArray = new BitArray((int)Math.Pow(2, 24));
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// creates all the cubes
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cubes = new WuColorCube[MaxColor];
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// initializes all the cubes
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for (Int32 cubeIndex = 0; cubeIndex < MaxColor; cubeIndex++) {
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cubes[cubeIndex] = new WuColorCube();
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}
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// resets the reference minimums
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cubes[0].RedMinimum = 0;
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cubes[0].GreenMinimum = 0;
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cubes[0].BlueMinimum = 0;
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// resets the reference maximums
|
|
cubes[0].RedMaximum = MaxSideIndex;
|
|
cubes[0].GreenMaximum = MaxSideIndex;
|
|
cubes[0].BlueMaximum = MaxSideIndex;
|
|
|
|
weights = new Int64[SideSize, SideSize, SideSize];
|
|
momentsRed = new Int64[SideSize, SideSize, SideSize];
|
|
momentsGreen = new Int64[SideSize, SideSize, SideSize];
|
|
momentsBlue = new Int64[SideSize, SideSize, SideSize];
|
|
moments = new Single[SideSize, SideSize, SideSize];
|
|
|
|
table = new Int32[256];
|
|
|
|
for (Int32 tableIndex = 0; tableIndex < 256; ++tableIndex) {
|
|
table[tableIndex] = tableIndex * tableIndex;
|
|
}
|
|
|
|
pixelIndex = 0;
|
|
imageSize = image.Width * image.Height;
|
|
|
|
quantizedPixels = new Int32[imageSize];
|
|
pixels = new Color[imageSize];
|
|
}
|
|
|
|
/// <summary>
|
|
/// See <see cref="IColorQuantizer.Prepare"/> for more details.
|
|
/// </summary>
|
|
public void AddColor(Color color) {
|
|
color = QuantizationHelper.ConvertAlpha(color);
|
|
|
|
// To count the colors
|
|
bitArray.Set(color.ToArgb() & 0x00ffffff, true);
|
|
|
|
Int32 indexRed = (color.R >> 3) + 1;
|
|
Int32 indexGreen = (color.G >> 3) + 1;
|
|
Int32 indexBlue = (color.B >> 3) + 1;
|
|
|
|
weights[indexRed, indexGreen, indexBlue]++;
|
|
momentsRed[indexRed, indexGreen, indexBlue] += color.R;
|
|
momentsGreen[indexRed, indexGreen, indexBlue] += color.G;
|
|
momentsBlue[indexRed, indexGreen, indexBlue] += color.B;
|
|
moments[indexRed, indexGreen, indexBlue] += table[color.R] + table[color.G] + table[color.B];
|
|
|
|
quantizedPixels[pixelIndex] = (indexRed << 10) + (indexRed << 6) + indexRed + (indexGreen << 5) + indexGreen + indexBlue;
|
|
pixels[pixelIndex] = color;
|
|
pixelIndex++;
|
|
}
|
|
|
|
/// <summary>
|
|
/// See <see cref="IColorQuantizer.Prepare"/> for more details.
|
|
/// </summary>
|
|
public Int32 GetColorCount() {
|
|
int result = 0;
|
|
|
|
for (int i = 0; i < bitArray.Length; i++) {
|
|
if (bitArray.Get(i)) {
|
|
result++;
|
|
}
|
|
}
|
|
return result;
|
|
}
|
|
|
|
/// <summary>
|
|
/// See <see cref="IColorQuantizer.Prepare"/> for more details.
|
|
/// </summary>
|
|
public List<Color> GetPalette(int colorCount) {
|
|
// preprocess the colors
|
|
CalculateMoments();
|
|
|
|
Int32 next = 0;
|
|
Single[] volumeVariance = new Single[MaxColor];
|
|
|
|
// processes the cubes
|
|
for (Int32 cubeIndex = 1; cubeIndex < colorCount; ++cubeIndex) {
|
|
// if cut is possible; make it
|
|
if (Cut(cubes[next], cubes[cubeIndex])) {
|
|
volumeVariance[next] = cubes[next].Volume > 1 ? CalculateVariance(cubes[next]) : 0.0f;
|
|
volumeVariance[cubeIndex] = cubes[cubeIndex].Volume > 1 ? CalculateVariance(cubes[cubeIndex]) : 0.0f;
|
|
} else // the cut was not possible, revert the index
|
|
{
|
|
volumeVariance[next] = 0.0f;
|
|
cubeIndex--;
|
|
}
|
|
|
|
next = 0;
|
|
Single temp = volumeVariance[0];
|
|
|
|
for (Int32 index = 1; index <= cubeIndex; ++index) {
|
|
if (volumeVariance[index] > temp) {
|
|
temp = volumeVariance[index];
|
|
next = index;
|
|
}
|
|
}
|
|
|
|
if (temp <= 0.0) {
|
|
colorCount = cubeIndex + 1;
|
|
break;
|
|
}
|
|
}
|
|
|
|
Int32[] lookupRed = new Int32[MaxColor];
|
|
Int32[] lookupGreen = new Int32[MaxColor];
|
|
Int32[] lookupBlue = new Int32[MaxColor];
|
|
|
|
tag = new Int32[MaxVolume];
|
|
|
|
// precalculates lookup tables
|
|
for (int k = 0; k < colorCount; ++k) {
|
|
Mark(cubes[k], k, tag);
|
|
|
|
long weight = Volume(cubes[k], weights);
|
|
|
|
if (weight > 0) {
|
|
lookupRed[k] = (int)(Volume(cubes[k], momentsRed) / weight);
|
|
lookupGreen[k] = (int)(Volume(cubes[k], momentsGreen) / weight);
|
|
lookupBlue[k] = (int)(Volume(cubes[k], momentsBlue) / weight);
|
|
} else {
|
|
lookupRed[k] = 0;
|
|
lookupGreen[k] = 0;
|
|
lookupBlue[k] = 0;
|
|
}
|
|
}
|
|
|
|
// copies the per pixel tags
|
|
for (Int32 index = 0; index < imageSize; ++index) {
|
|
quantizedPixels[index] = tag[quantizedPixels[index]];
|
|
}
|
|
|
|
reds = new Int32[colorCount + 1];
|
|
greens = new Int32[colorCount + 1];
|
|
blues = new Int32[colorCount + 1];
|
|
sums = new Int32[colorCount + 1];
|
|
indices = new Int32[imageSize];
|
|
|
|
// scans and adds colors
|
|
for (Int32 index = 0; index < imageSize; index++) {
|
|
Color color = pixels[index];
|
|
|
|
Int32 match = quantizedPixels[index];
|
|
Int32 bestMatch = match;
|
|
Int32 bestDistance = 100000000;
|
|
|
|
for (Int32 lookup = 0; lookup < colorCount; lookup++) {
|
|
Int32 foundRed = lookupRed[lookup];
|
|
Int32 foundGreen = lookupGreen[lookup];
|
|
Int32 foundBlue = lookupBlue[lookup];
|
|
Int32 deltaRed = color.R - foundRed;
|
|
Int32 deltaGreen = color.G - foundGreen;
|
|
Int32 deltaBlue = color.B - foundBlue;
|
|
|
|
Int32 distance = deltaRed * deltaRed + deltaGreen * deltaGreen + deltaBlue * deltaBlue;
|
|
|
|
if (distance < bestDistance) {
|
|
bestDistance = distance;
|
|
bestMatch = lookup;
|
|
}
|
|
}
|
|
|
|
reds[bestMatch] += color.R;
|
|
greens[bestMatch] += color.G;
|
|
blues[bestMatch] += color.B;
|
|
sums[bestMatch]++;
|
|
|
|
indices[index] = bestMatch;
|
|
}
|
|
|
|
List<Color> result = new List<Color>();
|
|
|
|
// generates palette
|
|
for (Int32 paletteIndex = 0; paletteIndex < colorCount; paletteIndex++) {
|
|
if (sums[paletteIndex] > 0) {
|
|
reds[paletteIndex] /= sums[paletteIndex];
|
|
greens[paletteIndex] /= sums[paletteIndex];
|
|
blues[paletteIndex] /= sums[paletteIndex];
|
|
}
|
|
|
|
Color color = Color.FromArgb(255, reds[paletteIndex], greens[paletteIndex], blues[paletteIndex]);
|
|
result.Add(color);
|
|
}
|
|
|
|
pixelIndex = 0;
|
|
return result;
|
|
}
|
|
|
|
/// <summary>
|
|
/// See <see cref="IColorQuantizer.Prepare"/> for more details.
|
|
/// </summary>
|
|
public Int32 GetPaletteIndex(Color color) {
|
|
return indices[pixelIndex++];
|
|
}
|
|
|
|
#endregion
|
|
}
|
|
} |