java图片处理(加水印、生成缩略图)等之Thumbnailator库
作者:互联网
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。
比任何现有自己基于jdk库写要稳定、高质量的多,不知道为啥还有那么多人非要自己重新造轮子,关键还造不过人家。
http://code.google.com/p/thumbnailator/
版本:thumbnailator-0.4.2.jar
<!-- https://mvnrepository.com/artifact/net.coobird/thumbnailator -->
<dependency>
<groupId>net.coobird</groupId>
<artifactId>thumbnailator</artifactId>
<version>0.4.8</version>
</dependency>
1、指定大小进行缩放
Java代码- //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
Java代码- //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
Java代码- //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
Java代码- //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"));
标签:java,Thumbnails,缩略图,a380,Thumbnailator,jpg,images,1280x1024,size 来源: https://www.cnblogs.com/zhjh256/p/10927687.html