google使用的開源的工具類Thumbnailator圖像處理
<dependency>
<groupId>net.coobird</groupId>
<artifactId>thumbnailator</artifactId>
<version>0.4.8</version>
</dependency>
使用接口例子 https://github.com/coobird/thumbnailator/wiki/Examples
1、指定大小進行縮放
Thumbnails.of("images/a380_1280x1024.jpg").size(200, 300)
2、按照比例進行縮放
Thumbnails.of("images/a380_1280x1024.jpg").scale(0.25f).toFile("c:/a380_25%.jpg");
3、不按照比例，指定大小進行縮放
//keepAspectRatio(false) 默認是按照比例縮放的
Thumbnails.of("images/a380_1280x1024.jpg").size(200,200).keepAspectRatio(false).toFile("c:/a380_200x200.jpg");
4、旋轉
//rotate(角度),正數：順時針負數：逆時針 Thumbnails.of("images/a380_1280x1024.jpg")Thumbnails.of("images/a380_1280x1024.jpg").size(1280,1024).watermark(Positions.BOTTOM_RIGHT,ImageIO.read(newFile("images/watermark.png")),0.5f).outputQuality(0.8f).toFile("c:/a380_watermark_bottom_right.jpg");
6、裁剪
//圖片中心400*400的區域
Thumbnails.of("images/a380_1280x1024.jpg")
Thumbnails.of("images/a380_1280x1024.jpg").size(1280,1024).outputFormat("png").toFile("c:/a380_1280x1024.png");
8、輸出到OutputStream //toOutputStream(流對象)OutputStream os = new FileOutputStream("c:/a380_1280x1024_OutputStream.png");
Thumbnails.of("images/a380_1280x1024.jpg").size(1280,1024).toOutputStream(os);
9、輸出到BufferedImage
//asBufferedImage()返回BufferedImage
BufferedImage thumbnail=Thumbnails.of("images/a380_1280x1024.jpg").size(1280,1024).asBufferedImage();
ImageIO.write(thumbnail,"jpg",newFile("c:/a380_1280x1024_BufferedImage.jpg"));
google使用的開源的工具類Thumbnailator圖像處理