Gets the top x numbers of color from BufferedImage - Java 2D Graphics

Java examples for 2D Graphics:BufferedImage

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Description

Gets the top x numbers of color from BufferedImage

Demo Code


//package com.java2s;

import java.awt.*;
import java.awt.image.BufferedImage;

import java.util.HashMap;
import java.util.Map;

public class Main {
    /**//from w ww. j a  v a  2 s  .  com
     * Gets the top x numbers
     * @param numColors - the number of colors to return
     * @return - An array of colors, indexed in descending order (Most Popular is 0 index).
     */
    public static Color[] getTopColors(int numColors,
            BufferedImage sourceImage) {
        Color[] returnColors = new Color[numColors];
        HashMap<Color, Integer> colorMap = new HashMap<Color, Integer>();
        int width = sourceImage.getWidth();
        int height = sourceImage.getHeight();
        for (int i = 0; i < width; i++) {
            for (int j = 0; j < height; j++) {
                Color pixelColor = new Color(sourceImage.getRGB(i, j), true);
                if (pixelColor.getAlpha() != 0) {
                    if (colorMap.containsKey(pixelColor)) {
                        colorMap.put(pixelColor,
                                colorMap.get(pixelColor) + 1);
                    } else {
                        colorMap.put(pixelColor, 1);
                    }
                }
            }
        }
        for (int c = 0; c < numColors; c++) {
            Color topColor = null;
            int max = -1;
            for (Map.Entry<Color, Integer> entry : colorMap.entrySet()) {
                if (max < entry.getValue()) {
                    topColor = entry.getKey();
                    max = entry.getValue();
                }
            }
            colorMap.remove(topColor);
            returnColors[c] = topColor;
        }
        return returnColors;
    }
}

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