Question

我必须对缓冲图像进行n轮行像素排序，循环每行并将当前像素的亮度与当前像素左边的亮度进行比较。如果电流的亮度小于左边的亮度，我需要交换像素的颜色。这是我目前的代码。

 public static int getRed(int rgb) { return (rgb >> 16) & 0xff; }
public static int getGreen(int rgb) { return (rgb >> 8) & 0xff; }
public static int getBlue(int rgb) { return rgb & 0xff; }
public static int rgbColour(int r, int g, int b) {
    return (r << 16) | (g << 8) | b;
}
public static double brightness(int rgb) {
    int r = getRed(rgb);
    int g = getGreen(rgb);
    int b = getBlue(rgb);
    return 0.21*r + 0.72*g + 0.07*b;
}

public static BufferedImage convertToGrayscale(BufferedImage img) {
    BufferedImage result = new BufferedImage(
            img.getWidth(), img.getHeight(), BufferedImage.TYPE_INT_RGB
        );
    for(int x = 0; x < img.getWidth(); x++) {
        for(int y = 0; y < img.getHeight(); y++) {
            int col = img.getRGB(x, y);
            int gr = (int)brightness(col);
            result.setRGB(x, y, rgbColour(gr, gr, gr));
        }
    }
    return result;
}

我给出的方法如下。

{{1}}

Answer 1

比较后您没有正确切换值：

for(int x =1; x<img.getWidth();x++){
    int temp = img.getRGB(x-1,y);
    int temp2 = img.getRGB(x, y);
...
    if (gr2 < gr) {
        result.setRGB(x, y, rgbColour(temp2,temp2,temp2)); // same as in img
        result.setRGB(x-1, y, rgbColour(temp,temp,temp)); // same as in img
    }
}

请尝试使用if-clause：

    ...
    if (gr2 < gr) { // swap values in result
        result.setRGB(x-1, y, rgbColour(temp2,temp2,temp2));
        result.setRGB(x, y, rgbColour(temp,temp,temp));
    } else { // keep values in result same as in img
        result.setRGB(x, y, rgbColour(temp2,temp2,temp2));
        result.setRGB(x-1, y, rgbColour(temp,temp,temp));
    }

交换两个像素的颜色

1 个答案: