pixel是通过标准jdk或android bitmap获取的图像32位像素数组

这个方法的滤波器尺寸是3*3，需要更大尺寸滤波器可以依此类推，ColorModel可根据各平台变化调整

private int[] medianFiltering(int[] pixel, int w, int h) {

int[] newPixel = new int[w * h];

int[] tempR = new int[9];

int[] tempG = new int[9];

int[] tempB = new int[9];

ColorModel cm = ColorModel.getRGBdefault();

// median values of the matrix

int r;

int g;

int b;

for (int y = 0; y < h; y++) {

for (int x = 0; x < w; x++) {

if (x == 0 || x == w - 1 || y == 0 || y == h - 1) {

newPixel[y * w + x] = pixel[y * w + x];

continue;

}

tempR[0] = cm.getRed(pixel[x - 1 + (y - 1) * w]);

tempR[1] = cm.getRed(pixel[x + (y - 1) * w]);

tempR[2] = cm.getRed(pixel[x + 1 + (y - 1) * w]);

tempR[3] = cm.getRed(pixel[x - 1 + y * w]);

tempR[4] = cm.getRed(pixel[x + y * w]);

tempR[5] = cm.getRed(pixel[x + 1 + y * w]);

tempR[6] = cm.getRed(pixel[x - 1 + (y + 1) * w]);

tempR[7] = cm.getRed(pixel[x + (y + 1) * w]);

tempR[8] = cm.getRed(pixel[x + 1 + (y + 1) * w]);

r = getMedianValue(tempR);

tempG[0] = cm.getGreen(pixel[x - 1 + (y - 1) * w]);

tempG[1] = cm.getGreen(pixel[x + (y - 1) * w]);

tempG[2] = cm.getGreen(pixel[x + 1 + (y - 1) * w]);

tempG[3] = cm.getGreen(pixel[x - 1 + y * w]);

tempG[4] = cm.getGreen(pixel[x + y * w]);

tempG[5] = cm.getGreen(pixel[x + 1 + y * w]);

tempG[6] = cm.getGreen(pixel[x - 1 + (y + 1) * w]);

tempG[7] = cm.getGreen(pixel[x + (y + 1) * w]);

tempG[8] = cm.getGreen(pixel[x + 1 + (y + 1) * w]);

g = getMedianValue(tempG);

tempB[0] = cm.getBlue(pixel[x - 1 + (y - 1) * w]);

tempB[1] = cm.getBlue(pixel[x + (y - 1) * w]);

tempB[2] = cm.getBlue(pixel[x + 1 + (y - 1) * w]);

tempB[3] = cm.getBlue(pixel[x - 1 + y * w]);

tempB[4] = cm.getBlue(pixel[x + y * w]);

tempB[5] = cm.getBlue(pixel[x + 1 + y * w]);

tempB[6] = cm.getBlue(pixel[x - 1 + (y + 1) * w]);

tempB[7] = cm.getBlue(pixel[x + (y + 1) * w]);

tempB[8] = cm.getBlue(pixel[x + 1 + (y + 1) * w]);

// median value

b = getMedianValue(tempB);

newPixel[y * w + x] = 255 << 24 | r << 16 | g << 8 | b;

}

}

return newPixel;

}