Thumbnailator java图片压缩，加水印，批量生成缩略图

地址：http://code.google.com/p/thumbnailator/

1、指定大小进行缩放

    //size(宽度, 高度)  

    /*
     * 若图片横比200小，高比300小，不变
     * 若图片横比200小，高比300大，高缩小到300，图片比例不变
     * 若图片横比200大，高比300小，横缩小到200，图片比例不变
     * 若图片横比200大，高比300大，图片按比例缩小，横为200或高为300
     */
    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

Java代码  收藏代码

    //scale(比例)
    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

//keepAspectRatio(false) 默认是按照比例缩放的
Thumbnails.of("images/a380_1280x1024.jpg")
        .size(200, 200)
        .keepAspectRatio(false)
        .toFile("c:/a380_200x200.jpg")

4、旋转

//rotate(角度),正数：顺时针 负数：逆时针
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

    //watermark(位置，水印图，透明度)
    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

    //sourceRegion()  

    //图片中心400*400的区域
    Thumbnails.of("images/a380_1280x1024.jpg")
            .sourceRegion(Positions.CENTER, 400,400)
            .size(200, 200)
            .keepAspectRatio(false)
            .toFile("c:/a380_region_center.jpg");  

    //图片右下400*400的区域
    Thumbnails.of("images/a380_1280x1024.jpg")
            .sourceRegion(Positions.BOTTOM_RIGHT, 400,400)
            .size(200, 200)
            .keepAspectRatio(false)
            .toFile("c:/a380_region_bootom_right.jpg");  

    //指定坐标
    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

//outputFormat(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

    //toOutputStream(流对象)
    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

//asBufferedImage() 返回BufferedImage
BufferedImage thumbnail = Thumbnails.of("images/a380_1280x1024.jpg")
        .size(1280, 1024)
        .asBufferedImage();
ImageIO.write(thumbnail, "jpg", new File("c:/a380_1280x1024_BufferedImage.jpg"));