Java生成缩略图Thumbnailator(转载)

转至：http://rensanning.iteye.com/blog/1545708

 

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

//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

//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"
));