公司項(xiàng)目需求需要將指紋采集儀器上傳上來的圖片與手寫簽名合成在一起德召，但是采集到的指紋圖片帶有白色的背景，合成之后會(huì)將簽名給覆蓋，所以需要將指紋圖片的白色背景變成透明！

直接上代碼

    public static int color_range = 210;
    public static Pattern pattern = Pattern.compile("[0-9]*");

    public static boolean isNo(String str) {
        return pattern.matcher(str).matches();
    }

    public static void convert(String path) {
        try {
            BufferedImage image = ImageIO.read(new File(path));
            ImageIcon imageIcon = new ImageIcon(image);
            BufferedImage bufferedImage = new BufferedImage(
                    imageIcon.getIconWidth(), imageIcon.getIconHeight(),
                    BufferedImage.TYPE_4BYTE_ABGR);
            Graphics2D g2D = (Graphics2D) bufferedImage.getGraphics();
            g2D.drawImage(imageIcon.getImage(), 0, 0,
                    imageIcon.getImageObserver());
            int alpha ;
            for (int j1 = bufferedImage.getMinY(); j1 < bufferedImage
                    .getHeight(); j1++) {
                for (int j2 = bufferedImage.getMinX(); j2 < bufferedImage
                        .getWidth(); j2++) {
                    int rgb = bufferedImage.getRGB(j2, j1);
                    if (colorInRange(rgb))
                        alpha = 0;
                    else
                        alpha = 255;
                    rgb = (alpha << 24) | (rgb & 0x00ffffff);
                    bufferedImage.setRGB(j2, j1, rgb);
                }
            }
            g2D.drawImage(bufferedImage, 0, 0, imageIcon.getImageObserver());
            // 生成圖片為PNG
            String outFile = path.substring(0, path.lastIndexOf("."));
            ImageIO.write(bufferedImage, "png", new File(outFile + ".png"));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static boolean colorInRange(int color) {
        int red = (color & 0xff0000) >> 16;
        int green = (color & 0x00ff00) >> 8;
        int blue = (color & 0x0000ff);
        if (red >= color_range && green >= color_range && blue >= color_range)
            return true;
        return false;
    }

測(cè)試類

    public static void main(String[] args) {
        String path="xxx";
        String color="200";//色差范圍0~255(建議10~50)
        if (isNo(color)) {
            color_range = 255 - Integer.parseInt(color);
            convert(path);
            log.info("轉(zhuǎn)換完成");
        } else {
            log.error("轉(zhuǎn)換失敗");
        }
    }