Java Compressed picture quality

Using the tool Thumbnailator, it is said that Thumbnailator is a very good image open source tool, easy to use. But not carefully, I just need to compress the picture, so that it occupies less space. Using MAVEN to introduce JAR packages

<!--thumbnail Image -<Dependency>    <groupId>Net.coobird</groupId>    <Artifactid>Thumbnailator</Artifactid>    <version>0.4.8</version></Dependency>

The code is as follows:

        Thumbnails.of ("c:/users/my/pictures/this/2.jpg")                  . Scale (1f).                  outputquality (0.25f)                  . ToFile ("C:/USERS/MY/PICTURES/THIS/2 (1). jpg");

The source image is 1.2MB and the image size is 157KB after compression

Java Compressed picture quality