Java获取彩色图像中的主色彩的实例代码

public static BufferedImage removeBlendPixels(BufferedImage image, int raidus) { 
  int width = image.getWidth(); 
  int height = image.getHeight(); 
  int[] pixels = new int[width * height]; 
  getRGB(image, 0, 0, width, height, pixels); 
  // 创建处理结果 
  BufferedImage resultImg = createCompatibleDestImage(image, null); 
  setRGB(resultImg, 0, 0, width, height, pixels); 
  // 灰度化与梯度求取 
  byte[] grayData = getGrayData(pixels, width, height); 
  byte[] binaryData = getGrident(grayData, width, height); 
  int index = 0; 
  for (int row = 1; row < height - 1; row++) { 
   for (int col = 1; col < width - 1; col++) { 
    index = row * width + col; 
    int pixel = (binaryData[index] & 0xff); 
    if (pixel > 0) { 
     // 半径扫描操作 
     int mindis = Integer.MAX_VALUE; 
     int minrow = -1; 
     int mincol = -1; 
     int nr = 0; 
     int nc = 0; 
     int index2 = 0; 
     for (int subrow = -raidus; subrow <= raidus; subrow++) { 
      nr = row + subrow; 
      if (nr < 0 || nr >= height) { 
       continue; 
      } 
      for (int subcol = -raidus; subcol <= raidus; subcol++) { 
       nc = col + subcol; 
       if (nc < 0 || nc >= width) { 
        continue; 
       } 
       index2 = nr * width + nc; 
       int value = (binaryData[index2] & 0xff); 
       if (value == 0) { 
        int distance = distanceColor(image.getRGB(nc, nr), image.getRGB(col, row)); 
        if (distance < mindis) { 
         mindis = distance; 
         minrow = nr; 
         mincol = nc; 
        } 
       } 
      } 
     } 
     resultImg.setRGB(col, row, image.getRGB(mincol, minrow)); 
    } 
   } 
  } 
  return resultImg; 
 } 
 public static int distanceColor(int rgb, int rgb2) { 
  // Color one 
  int r1 = (rgb >> 16) & 0xff; 
  int g1 = (rgb >> 8) & 0xff; 
  int b1 = rgb & 0xff; 
  // Color two 
  int r2 = (rgb2 >> 16) & 0xff; 
  int g2 = (rgb2 >> 8) & 0xff; 
  int b2 = rgb2 & 0xff; 
  // distance 
  int rr = r1 - r2; 
  int gg = g1 - g2; 
  int bb = b1 - b2; 
  int sum = (int) Math.sqrt(rr * rr + gg * gg + bb * bb); 
  return sum; 
 } 
 public static byte[] getGrayData(int[] inPixels, int width, int height) { 
  // 图像灰度化 
  byte[] outPixels = new byte[width * height]; 
  int index = 0; 
  for (int row = 0; row < height; row++) { 
   int tr = 0, tg = 0, tb = 0; 
   for (int col = 0; col < width; col++) { 
    index = row * width + col; 
    tr = (inPixels[index] >> 16) & 0xff; 
    tg = (inPixels[index] >> 8) & 0xff; 
    tb = inPixels[index] & 0xff; 
    int gray = (int) (0.299 * tr + 0.587 * tg + 0.114 * tb); 
    outPixels[index] = (byte) (gray & 0xff); 
   } 
  } 
  return outPixels; 
 } 
 public static byte[] getGrident(byte[] inPixels, int width, int height) { 
  byte[] outPixels = new byte[width * height]; 
  int index = 0; 
  for (int row = 0; row < height; row++) { 
   int tr = 0; 
   for (int col = 0; col < width; col++) { 
    if (row == 0 || col == 0 || (row == height - 1) || (col == width - 1)) { 
     index = row * width + col; 
     outPixels[index] = (byte) (0x00); 
     continue; 
    } 
    int xg = 0, yg = 0; 
    for (int sr = -1; sr <= 1; sr++) { 
     for (int sc = -1; sc <= 1; sc++) { 
      int nrow = row + sr; 
      int ncol = col + sc; 
      if (nrow < 0 || nrow >= height) { 
       nrow = 0; 
      } 
      if (ncol < 0 || ncol >= width) { 
       ncol = 0; 
      } 
      index = nrow * width + ncol; 
      tr = (inPixels[index] & 0xff); 
      xg += X_SOBEL[sr + 1][sc + 1] * tr; 
      yg += Y_SOBEL[sr + 1][sc + 1] * tr; 
     } 
    } 
    index = row * width + col; 
    int g = (int) Math.sqrt(xg * xg + yg * yg); 
    outPixels[index] = (byte) (clamp(g) & 0xff); 
   } 
  } 
  return outPixels; 
 } 

public static final int[][] X_SOBEL = new int[][] { { -1, -2, -1 }, { 0, 0, 0 }, { 1, 2, 1 } }; 
public static final int[][] Y_SOBEL = new int[][] { { -1, 0, 1 }, { -2, 0, 2 }, { -1, 0, 1 } }; 
public static final int BLOCK_PIXEL_RADIUS = 5; 

int width = result.getWidth(); 
int height = result.getHeight(); 
Map<Integer, Integer> colorIndexMap = new HashMap<Integer, Integer>(); 
for (int row = 0; row < height; row++) { 
 for (int col = 0; col < width; col++) { 
  int pixelValue = result.getRGB(col, row); 
  if (!colorIndexMap.containsKey(pixelValue)) { 
   colorIndexMap.put(pixelValue, pixelValue); 
  } 
 } 
} 
// now scan pixel value 
// return result 
System.out.println("number of color = " + colorIndexMap.size()); 
return colorIndexMap.keySet().toArray(new Integer[0]);

public static void main(String[] args) { 
 File file = new File("D:\\gloomyfish\\bigmonkey.png"); 
 File resultFile = new File("D:\\gloomyfish\\result.png"); 
 try { 
  BufferedImage image = ImageIO.read(file); 
  BufferedImage result = removeBlendPixels(image, BLOCK_PIXEL_RADIUS); 
  ImageIO.write(result, "png", resultFile); 
  Integer[] colors = extractColors(result); 
  System.out.println("total colors : " + colors.length); 
 } catch (IOException e) { 
  e.printStackTrace(); 
 } 
}