Thumbnailator 是一个为Java界面更流畅的缩略图生成库。从API提供现有的图像文件和图像对象的缩略图中简化了缩略过程,两三行代码就能够从现有图片生成缩略图,且允许微调缩略图生成,同时保持了需要写入到最低限度的代码量。同时还支持根据一个目录批量生成缩略图。
http://code.google.com/p/thumbnailator/
版本:thumbnailator-0.4.2.jar
原图如下:
1、指定大小进行缩放
- Thumbnails.of("images/a380_1280x1024.jpg")
- .size(200, 300)
- .toFile("c:/a380_200x300.jpg");
- Thumbnails.of("images/a380_1280x1024.jpg")
- .size(2560, 2048)
- .toFile("c:/a380_2560x2048.jpg");
2、按照比例进行缩放
- Thumbnails.of("images/a380_1280x1024.jpg")
- .scale(0.25f)
- .toFile("c:/a380_25%.jpg");
- Thumbnails.of("images/a380_1280x1024.jpg")
- .scale(1.10f)
- .toFile("c:/a380_110%.jpg");
3、不按照比例,指定大小进行缩放
- Thumbnails.of("images/a380_1280x1024.jpg")
- .size(200, 200)
- .keepAspectRatio(false)
- .toFile("c:/a380_200x200.jpg");
4、旋转
- Thumbnails.of("images/a380_1280x1024.jpg")
- .size(1280, 1024)
- .rotate(90)
- .toFile("c:/a380_rotate+90.jpg");
- Thumbnails.of("images/a380_1280x1024.jpg")
- .size(1280, 1024)
- .rotate(-90)
- .toFile("c:/a380_rotate-90.jpg");
5、水印
- Thumbnails.of("images/a380_1280x1024.jpg")
- .size(1280, 1024)
- .watermark(Positions.BOTTOM_RIGHT, ImageIO.read(new File("images/watermark.png")), 0.5f)
- .outputQuality(0.8f)
- .toFile("c:/a380_watermark_bottom_right.jpg");
- Thumbnails.of("images/a380_1280x1024.jpg")
- .size(1280, 1024)
- .watermark(Positions.CENTER, ImageIO.read(new File("images/watermark.png")), 0.5f)
- .outputQuality(0.8f)
- .toFile("c:/a380_watermark_center.jpg");
6、裁剪
- Thumbnails.of("images/a380_1280x1024.jpg")
- .sourceRegion(Positions.CENTER, 400,400)
- .size(200, 200)
- .keepAspectRatio(false)
- .toFile("c:/a380_region_center.jpg");
- Thumbnails.of("images/a380_1280x1024.jpg")
- .sourceRegion(Positions.BOTTOM_RIGHT, 400,400)
- .size(200, 200)
- .keepAspectRatio(false)
- .toFile("c:/a380_region_bootom_right.jpg");
- Thumbnails.of("images/a380_1280x1024.jpg")
- .sourceRegion(600, 500, 400, 400)
- .size(200, 200)
- .keepAspectRatio(false)
- .toFile("c:/a380_region_coord.jpg");
7、转化图像格式
- Thumbnails.of("images/a380_1280x1024.jpg")
- .size(1280, 1024)
- .outputFormat("png")
- .toFile("c:/a380_1280x1024.png");
- Thumbnails.of("images/a380_1280x1024.jpg")
- .size(1280, 1024)
- .outputFormat("gif")
- .toFile("c:/a380_1280x1024.gif");
8、输出到OutputStream
- OutputStream os = new FileOutputStream("c:/a380_1280x1024_OutputStream.png");
- Thumbnails.of("images/a380_1280x1024.jpg")
- .size(1280, 1024)
- .toOutputStream(os);
9、输出到BufferedImage
- BufferedImage thumbnail = Thumbnails.of("images/a380_1280x1024.jpg")
- .size(1280, 1024)
- .asBufferedImage();
- ImageIO.write(thumbnail, "jpg", new File("c:/a380_1280x1024_BufferedImage.jpg"));
需要注意的是,对于CMYK模式的图像,由于JDK的Bug,目前还不能够处理,会出以下异常:
引用
javax.imageio.IIOException: Unsupported Image Type
at com.sun.imageio.plugins.jpeg.JPEGImageReader.readInternal(JPEGImageReader.java:1063)
at com.sun.imageio.plugins.jpeg.JPEGImageReader.read(JPEGImageReader.java:1034)
at javax.imageio.ImageReader.read(ImageReader.java:940)
at net.coobird.thumbnailator.tasks.io.FileImageSource.read(Unknown Source)