JPEG Compression JPEG images are able to achieve remarkable amounts of file compression by using a method called
Lossy Compression. Simply stated, this method looks at the information contained in the bitmaps, much of which is hidden, and throws out all but the visible information. This achieves a good looking image
with a manageable file size.
Unfortunately, because much information has been deleted from the file, if you attempt to resize the JPEG and resave it, the image quality will degrade
noticeably. The amount of compression also affects the appearance of the image.
Xara measures compression kind
of backwards (in your editor's opinion). A file that shows 80% on the compression slider has been compressed 20%. See what I mean?
For comparison, the JPEG image shown here has 0% compression or 100% on the Xara scale. Notice how clean the text appears and how solid the
colored band at the top of the image is. The file size is 51K.