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Chapter 12: Image Compression

JPEGTool

screendump of JPEGTool

The JPEGTool application reads an image from a named file and displays it in a tabbed pane. In the other pane, a version of the image that has been subjected to one cycle of JPEG compression and decompression is displayed. Compression quality, a value between 0.0 and 1.0, can be varied using the slider beneath the tabbed display. The compression ratio and RMS error for this quality setting are shown beneath the slider. A menu is provided, allowing the output image and the difference between the input and output images to be saved.

The application consists of one source file, JPEGTool.java, which compiles into JPEGTool.class and JPEGTool$Controls.class. The .class files are available individually and as part of a single package, the JAR file JPEGTool.jar. You can install the application by copying this JAR file, along with either the MS-DOS batch file JPEGTool.bat or the bash shell script JPEGTool.sh, as appropriate. The batch file or script should be edited to reflect the new location of the JAR file.


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