Java图片处理工具类库

maven

<dependency>
    <groupId>net.coobird</groupId>
    <artifactId>thumbnailator</artifactId>
    <version>0.4.8</version>
</dependency>

java

//原图像素 1024*682  

//缩放  
Thumbnails.of(path+"/image/blue.jpg").size(100, 100).toFile(path+"/thumb/thumb_blue.jpg");  
Thumbnails.of(path+"/image/blue.jpg").size(2560, 2048).toFile(path+"/thumb/thumb_large_blue.jpg"); 

//按照比例缩放  
Thumbnails.of(path+"/image/blue.jpg").scale(0.7).toFile(path+"/thumb/thumb_0.7_blue.jpg");  
Thumbnails.of(path+"/image/blue.jpg").scale(1.2).toFile(path+"/thumb/thumb_1.2_blue.jpg");  

//keepAspectRatio(false) 默认是按照比例缩放的    
Thumbnails.of(path+"/image/blue.jpg").size(200, 200).keepAspectRatio(false).toFile(path+"/thumb/thumb_noscale_blue.jpg");  

//旋转  
Thumbnails.of(path+"/image/blue.jpg").size(1024, 682).rotate(90).toFile(path+"/thumb/thumb_rotate90_blue.jpg");  
Thumbnails.of(path+"/image/blue.jpg").size(1024, 682).rotate(-90).toFile(path+"/thumb/thumb_rotate-90_blue.jpg");  

//水印  
Thumbnails.of(path+"/image/blue.jpg").size(1024, 682).watermark(Positions.BOTTOM_RIGHT, ImageIO.read(new File(path+"/image/baidu.png")), 0.5f).toFile(path+"/thumb/thumb_watermarkbr_blue.jpg");;  
Thumbnails.of(path+"/image/blue.jpg").size(1024, 682).watermark(Positions.CENTER, ImageIO.read(new File(path+"/image/baidu.png")), 0.8f).toFile(path+"/thumb/thumb_watermarkc_blue.jpg");  

//裁剪  
Thumbnails.of(path+"/image/blue.jpg").sourceRegion(Positions.CENTER, 400,400).size(200, 200).keepAspectRatio(false).toFile(path+"/thumb/thumb_regioncenter_blue.jpg");  
Thumbnails.of(path+"/image/blue.jpg").sourceRegion(Positions.BOTTOM_RIGHT, 400,400).size(200, 200).keepAspectRatio(false).toFile(path+"/thumb/thumb_regionbr_blue.jpg");  
Thumbnails.of(path+"/image/blue.jpg").sourceRegion(650 , 500 , 400 , 400).size(200, 200).keepAspectRatio(false).toFile(path+"/thumb/thumb_realregion_blue.jpg");  

//转换图像格式  
Thumbnails.of(path+"/image/blue.jpg").size(1024, 682).outputFormat("png").toFile(path+"/thumb/thumb_blue.png");  
Thumbnails.of(path+"/image/blue.jpg").size(1024, 682).outputFormat("gif").toFile(path+"/thumb/thumb_blue.gif");  
Thumbnails.of(path+"/image/blue.jpg").size(1024, 682).outputFormat("JPEG").toFile(path+"/thumb/thumb_blue.jpeg");  

//输出到outputstream中  
OutputStream outputStream = new FileOutputStream(new File(path+"/thumb/thumb_output_blue.gif"));  
Thumbnails.of(path+"/image/blue.jpg").size(1024, 682).toOutputStream(outputStream);  

//asBufferedImage() 返回BufferedImage    
BufferedImage thumbnail = Thumbnails.of(path+"/image/blue.jpg").size(1024, 682).asBufferedImage();    
ImageIO.write(thumbnail, "jpg", new File(path+"/thumb/thumb_bufferedImage_output_blue.gif"));