TABLE OF CONTENTS JPEG is a sophisticated lossy/lossless compression method for color or grayscale still images (not videos). It does not handle bi-level (black and white) images very well. It also works best on continuous-tone images, where adjacent pixels have similar colors. An important feature of JPEG is its use of many parameters, allowing the user to adjust the amount of the data lost (and thus also the compression ratio) over a very wide range. Often, the eye cannot see any image degradation even at compression factors of 10 or 20. There are two operating modes, lossy (also called baseline) and lossless (which typically produces compression ratios of around 0.5). Most implementations support just the lossy mode. This mode includes progressive and hierarchical coding. A few of the many references to JPEG are [Pennebaker and Mitchell 92], [Wallace 91], and [Zhang 90].
JPEG is a compression method, not a complete standard for image representation. This is why it does not specify image features such as pixel aspect ratio, color space, or interleaving of bitmap rows.
JPEG has been designed as a compression method for continuous-tone images. The main goals of JPEG compression are the following:
High compression ratios, especially in cases where image quality is judged as very good to excellent.
The use of many parameters, allowing knowledgeable users to experiment and achieve the desired compression/quality trade-off.
Obtaining good results with any kind of continuous-tone image, regardless of image dimensions, color spaces, pixel aspect ratios, or other image features.
A sophisticated,...
