Do JPEG Encoders Differ Significantly in Quality?
Jeffrey M. Cunningham · Microform and Imaging Review · 2000
The claim is often made that JPEG encoders vary a great deal in their abilities to produce small, acceptable quality JPEG files. It has often been asserted that PhotoShop produces poor quality, “bloated” JPEGs when compared with PaintShop Pro, ImageOptimizer, or even PhotoShop's poor web-cousin ImageReady. For web use, where excessive download times may mean the difference between someone spending serious time browsing a site or hitting their back button in exasperation, this is an important issue. And having spent many hours building up a website that has been perhaps generously referred to as a “graphics-pig”, I myself had an interest in finding out if these aims were true. So I did some research, wrote an analysis code and performed a number of experiments from which emerged some useful results.