Abstract:
|
Image source coding became very important in the 80's. There were some key factors that helped to that
data (image) compression revolution. First, the idea of digital image: an image composed by a set of niteprecision
coe cients placed over a nite and discrete grid. To represent the image one could scan its coe cients
and concatenate the coe cients binary representation. This strategy does not take into account any of the
characteristics of the input signal (the image). Moreover it is not an e cient representation of the image and
compression techniques are therefore necessary. Second, researchers had started to develop new techniques and
softwares in the eld of text compression and generic data coding some years ago (see [10, 32]). Third, the
presence of digital image processing in the market increased due to its simplicity, performance and results.
Those are, under my opinion, the key factors that promoted image entropy coding at the research level in the
80's.
On the other hand, this data (image) compression revolution helped to trigger another spectacular growth: the
number of plain Internet users. A large amount of people started to share information: plain and formatted
text, photo, music, video,... These information exchanges required better-performed techniques in terms of ratedistortion
characteristics. User's needs increased and researchers, developers and producers had to upgrade the
system's quality and capacity. This Internet growth, in the 1990s, would not have been possible without the
previous image compression systems quality rise. |