java将图片背景替换为透明

系统管理员 2023-06-21 10:25 39阅读 0赞

/** * 将背景替换为透明 * @param imgBytes * @return * @throws IOException */
    public byte[] changeImgColor(byte[] imgBytes) throws IOException { 
    
        //将原图片的二进制转化为ImageIcon
        ImageIcon imageIcon = new ImageIcon(imgBytes);
        int width = imageIcon.getIconWidth();
        int height = imageIcon.getIconHeight();
    
        //图片缓冲流
        BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_4BYTE_ABGR);
        Graphics2D graphics2D = (Graphics2D) bufferedImage.getGraphics();
        graphics2D.drawImage(imageIcon.getImage(), 0, 0, imageIcon.getImageObserver());
    
        int alpha = 0;
    
        for(int i = bufferedImage.getMinX(); i < width; i++) { 
            for(int j = bufferedImage.getMinY(); j < height; j++) { 
                int rgb = bufferedImage.getRGB(i, j);
    
                int RGB = bufferedImage.getRGB(bufferedImage.getMinX(), bufferedImage.getMinY());
                int r = (rgb & 0xff0000) >>16;
                int g = (rgb & 0xff00) >> 8;
                int b = (rgb & 0xff);
                int R = (RGB & 0xff0000) >>16;
                int G = (RGB & 0xff00) >> 8;
                int B = (RGB & 0xff);
                //a为色差范围值，渐变色边缘处理，数值需要具体测试，50左右的效果比较可以
                int a = 45;
                if(Math.abs(R-r) < a && Math.abs(G-g) < a && Math.abs(B-b) < a ) { 
                    alpha = 0;
                } else { 
                    alpha = 255;
                }
                rgb = (alpha << 24)|(rgb & 0x00ffffff);
                bufferedImage.setRGB(i,j,rgb);
            }
        }
    
        graphics2D.drawImage(bufferedImage, 0, 0, imageIcon.getImageObserver());
    
        //新建字节输出流，用来存放替换完背景的图片
        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
    
        ImageIO.write(bufferedImage, "png", byteArrayOutputStream);
        return byteArrayOutputStream.toByteArray();
    }