BufferedImage将图片切成圆形

桃扇骨 2023-10-12 22:49 9阅读 0赞

原图

![e4ae01e330e44cfa944fae34c15ef9b3.png][]

修改后

![105872dd98244aa693303867efbc7eb2.png][]

## 方法一 ##

//文件路径
    File imageFile = new File(path);

public  BufferedImage changeImages(File imageFile) {
    	        BufferedImage  avatarImage = null;
    	        try {
    	        	avatarImage = ImageIO.read(imageFile);
    avatarImage = scaleByPercentage(avatarImage, avatarImage.getWidth(),  avatarImage.getWidth());
     int width = avatarImage.getWidth();
    	        	 
    	            // 透明底的图片  
    	            BufferedImage formatAvatarImage = new BufferedImage(avatarImage.getWidth(), avatarImage.getHeight(), BufferedImage.TYPE_4BYTE_ABGR);
    	            Graphics2D graphics = formatAvatarImage.createGraphics();
    	            //把图片切成一个园
    	            graphics.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
    	            //留一个像素的空白区域，这个很重要，画圆的时候把这个覆盖
    	            int border = 1;
    	          //图片是一个圆型
    	            Ellipse2D.Double shape = new Ellipse2D.Double(border, border, width - border * 2, width - border * 2);
    	          //需要保留的区域
    	            graphics.setClip(shape);
    	            graphics.drawImage(avatarImage, border, border, width - border * 2, width - border * 2, null);
    	            //在圆图外面再画一个圆
    	            //新创建一个graphics，这样画的圆不会有锯齿
    //	            graphics = formatAvatarImage.createGraphics();
    //	            graphics.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
    //	            int border1 = 3;
    //	            //画笔是4.5个像素，BasicStroke的使用可以查看下面的参考文档
    //	            //使画笔时基本会像外延伸一定像素，具体可以自己使用的时候测试
    //	            Stroke s = new BasicStroke(5F, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND);
    //	            graphics.setStroke(s);
    //	            graphics.setColor(Color.WHITE);
    //	            graphics.drawOval(border1, border1, width - border1 * 2, width - border1 * 2);
    //	            graphics.dispose();
    //	          
    	            return formatAvatarImage;
    	        } catch (Exception e) {
    	            e.printStackTrace();
    	        }
    	        return null;
    	    }

/**
         * 缩小Image，此方法返回源图像按给定宽度、高度限制下缩放后的图像
         *
         * @param inputImage
         *            ：压缩后宽度
         *            ：压缩后高度
         * @throws java.io.IOException
         *             return
         */
        public BufferedImage scaleByPercentage(BufferedImage inputImage, int newWidth, int newHeight){
            // 获取原始图像透明度类型
            try {
                int type = inputImage.getColorModel().getTransparency();
                int width = inputImage.getWidth();
                int height = inputImage.getHeight();
                // 开启抗锯齿
                RenderingHints renderingHints = new RenderingHints(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
                // 使用高质量压缩
                renderingHints.put(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
                BufferedImage img = new BufferedImage(newWidth, newHeight, type);
                Graphics2D graphics2d = img.createGraphics();
                graphics2d.setRenderingHints(renderingHints);
                graphics2d.drawImage(inputImage, 0, 0, newWidth, newHeight, 0, 0, width, height, null);
                graphics2d.dispose();
                return img;
     
            }catch (Exception e) {
                e.printStackTrace();
            }
            return null;
        }

## 方法二 ##

String url = "https://www.pngall.com/wp-content/uploads/13/Christmas-Golden-Bell-PNG-Photo.png";
    		BufferedImage avatarImage = ImageIO.read(new URL(url));
    //		 avatarImage = scaleByPercentage(avatarImage, avatarImage.getWidth(),  avatarImage.getWidth());
             int width = 120;
    		// 透明底的图片
    		BufferedImage formatAvatarImage = new BufferedImage(width, width, BufferedImage.TYPE_4BYTE_ABGR);
    		Graphics2D graphics = formatAvatarImage.createGraphics();
    		// 把图片切成一个圓
    		{
    			graphics.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
    			// 留一个像素的空白区域，这个很重要，画圆的时候把这个覆盖
    			int border = 1;
    			// 图片是一个圆型
    			Ellipse2D.Double shape = new Ellipse2D.Double(border, border, width - border * 2, width - border * 2);
    			// 需要保留的区域
    			graphics.setClip(shape);
    			graphics.drawImage(avatarImage, border, border, width - border * 2, width - border * 2, null);
    			graphics.dispose();
    		}
    		// 在圆图外面再画一个圆
    		{
    			// 新创建一个graphics，这样画的圆不会有锯齿
    			graphics = formatAvatarImage.createGraphics();
    			graphics.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
    			int border = 3;
    			// 画笔是4.5个像素，BasicStroke的使用可以查看下面的参考文档
    			// 使画笔时基本会像外延伸一定像素，具体可以自己使用的时候测试
    			Stroke s = new BasicStroke(4.5F, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND);
    			graphics.setStroke(s);
    			graphics.setColor(Color.WHITE);
    			graphics.drawOval(border, border, width - border * 2, width - border * 2);
    			graphics.dispose();
    		}
    		try (OutputStream os = new FileOutputStream("d:/temp-avatar.png")) {
    			ImageIO.write(formatAvatarImage, "PNG", os);
    		}
    		{
    			url = "https://img-blog.csdn.net/20180529213113521";
    			BufferedImage srcImg = ImageIO.read(new URL(url));
    			// scrImg加载完之后没有任何颜色
    			BufferedImage blankImage = new BufferedImage(srcImg.getWidth(), srcImg.getHeight(),
    					BufferedImage.TYPE_INT_RGB);
    			graphics = blankImage.createGraphics();
    			graphics.drawImage(srcImg, 0, 0, null);
    
    			int x = (blankImage.getWidth() - width) / 2;
    			int y = (blankImage.getHeight() - width) / 2;
    			graphics.drawImage(formatAvatarImage, x, y, width, width, null);
    			try (OutputStream os = new FileOutputStream("d:/temp-avatar.png")) {
    				ImageIO.write(blankImage, "PNG", os);
    			}
    		}

[e4ae01e330e44cfa944fae34c15ef9b3.png]: https://img-blog.csdnimg.cn/e4ae01e330e44cfa944fae34c15ef9b3.png
[105872dd98244aa693303867efbc7eb2.png]: https://img-blog.csdnimg.cn/105872dd98244aa693303867efbc7eb2.png