java中用Thumbnailator对图片各种处理的方法
jar自己网上下载一下，maven的话添加依赖即可
<!-- https://mvnrepository.com/artifact/net.coobird/thumbnailator -->
<dependency>
<groupId>net.coobird</groupId>
<artifactId>thumbnailator</artifactId>
<version>0.4.8</version>
</dependency>
private void test1() throws IOException {
/*
* size(width,height) 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/test.jpg").size(200, 300).toFile(
"C:/image_200x300.jpg");
Thumbnails.of("images/test.jpg").size(2560, 2048).toFile(
"C:/image_2560x2048.jpg");
}
/**
* 按照比例进行缩放
*
* @throws IOException
*/
private void test2() throws IOException {
/**
* scale(比例)
*/
Thumbnails.of("images/test.jpg").scale(0.25f)
.toFile("C:/image_25%.jpg");
Thumbnails.of("images/test.jpg").scale(1.10f).toFile(
"C:/image_110%.jpg");
}
/**
* 不按照比例，指定大小进行缩放
*
* @throws IOException
*/
private void test3() throws IOException {
/**
* keepAspectRatio(false) 默认是按照比例缩放的
*/
Thumbnails.of("images/test.jpg").size(120, 120).keepAspectRatio(false)
.toFile("C:/image_120x120.jpg");
}
/**
* 旋转
*
* @throws IOException
*/
private void test4() throws IOException {
/**
* rotate(角度),正数：顺时针 负数：逆时针
*/
Thumbnails.of("images/test.jpg").size(1280, 1024).rotate(90).toFile(
"C:/image+90.jpg");
Thumbnails.of("images/test.jpg").size(1280, 1024).rotate(-90).toFile(
"C:/iamge-90.jpg");
}
/**
* 水印
*
* @throws IOException
*/
private void test5() throws IOException {
/**
* watermark(位置，水印图，透明度)
*/
Thumbnails.of("images/test.jpg").size(1280, 1024).watermark(
Positions.BOTTOM_RIGHT,
ImageIO.read(new File("images/watermark.png")), 0.5f)
.outputQuality(0.8f).toFile(
"C:/image_watermark_bottom_right.jpg");
Thumbnails.of("images/test.jpg").size(1280, 1024).watermark(
Positions.CENTER,
ImageIO.read(new File("images/watermark.png")), 0.5f)
.outputQuality(0.8f).toFile("C:/image_watermark_center.jpg");
}
/**
* 裁剪
*
* @throws IOException
*/
private void test6() throws IOException {
/**
* 图片中心400*400的区域
*/
Thumbnails.of("images/test.jpg").sourceRegion(Positions.CENTER, 400,
400).size(200, 200).keepAspectRatio(false).toFile(
"C:/image_region_center.jpg");
/**
* 图片右下400*400的区域
*/
Thumbnails.of("images/test.jpg").sourceRegion(Positions.BOTTOM_RIGHT,
400, 400).size(200, 200).keepAspectRatio(false).toFile(
"C:/image_region_bootom_right.jpg");
/**
* 指定坐标
*/
Thumbnails.of("images/test.jpg").sourceRegion(600, 500, 400, 400).size(
200, 200).keepAspectRatio(false).toFile(
"C:/image_region_coord.jpg");
}
/**
* 转化图像格式
*
* @throws IOException
*/
private void test7() throws IOException {
/**
* outputFormat(图像格式)
*/
Thumbnails.of("images/test.jpg").size(1280, 1024).outputFormat("png")
.toFile("C:/image_1280x1024.png");
Thumbnails.of("images/test.jpg").size(1280, 1024).outputFormat("gif")
.toFile("C:/image_1280x1024.gif");
}
/**
* 输出到OutputStream
*
* @throws IOException
*/
private void test8() throws IOException {
/**
* toOutputStream(流对象)
*/
OutputStream os = new FileOutputStream(
"C:/image_1280x1024_OutputStream.png");
Thumbnails.of("images/test.jpg").size(1280, 1024).toOutputStream(os);
}
/**
* 输出到BufferedImage
*
* @throws IOException
*/
private void test9() throws IOException {
/**
* asBufferedImage() 返回BufferedImage
*/
BufferedImage thumbnail = Thumbnails.of("images/test.jpg").size(1280,
1024).asBufferedImage();
ImageIO.write(thumbnail, "jpg", new File(
"C:/image_1280x1024_BufferedImage.jpg"));
}