Java也可以非常简单的实现图片灰度化

avgColor = red * 0.299f + green * 0.587f + blue * 0.114f

avgColor = (red + green + blue) / 3.0f

private Color avg1(int red, int green, int blue) {    int avg = Math.round((red * 0.299f + green * 0.587f + blue * 0.114f));    return new Color(avg, avg, avg);}private Color avg2(int red, int green, int blue) {    int avg = Math.round((red + green + blue) / 3);    return new Color(avg, avg, avg);}
@Testpublic void testRender() throws IOException {    String file = "http://i0.download.fd.52shubiao.com/t_960x600/g1/M00/10/17/oYYBAFWvR5-IeXHuAAd5kPb8eSgAACm0QF50xIAB3mo414.jpg";    // 从网络上下载图片    BufferedImage img = ImageIO.read(FileReadUtil.getStreamByFileName(file));

    int w = img.getWidth(), h = img.getHeight();    // 创建新的灰度图片画板    BufferedImage gray = new BufferedImage(w, h, img.getType());    Graphics2D g2d = gray.createGraphics();    g2d.setColor(null);    g2d.fillRect(0, 0, w, h);
    for (int x = 0; x < w; x++) {        for (int y = 0; y<h; y++) {            // 针对像素点的颜色灰度化之后，重新绘制            int color = img.getRGB(x, y);            Color grayColor = avg1((color & 0xff0000) >> 16, (color & 0xff00) >> 8, color & 0x0000ff);            g2d.setColor(grayColor);            g2d.fillRect(x, y, 1, 1);        }    }    g2d.dispose();    System.out.printf("渲染完成");}

@Testpublic void testImgGrayAlg() {    String img = "https://c-ssl.duitang.com/uploads/item/201809/16/20180916175034_Gr2hk.thumb.1000_0.jpeg";    BufferedImage out = ImgPixelWrapper.build()            .setSourceImg(img)            .setPixelType(PixelStyleEnum.GRAY_ALG)            .build()            .asBufferedImg();    System.out.println(out);}