Apparatus and methods for digital image compression

Abstract

Methods and systems for compression of digital images (still or motion sequences) are provided wherein predetermined criteria may be used to identify a plurality of areas of interest in the image, and each area of interest is encoded with a corresponding quality level (Q-factor). In particular, the predetermined criteria may be derived from measurements of where a viewing audience is focusing their gaze (area of interest). In addition, the predetermined criteria may be used to create areas of interest in an image in order to focus an observer's attention to that area. Portions of the image outside of the areas of interest are encoded at a lower quality factor and bit rate. The result is higher compression ratios without adversely affecting a viewer's perception of the overall quality of the image.

1 . A digital image compression method comprising:
 identifying a plurality of areas of interest in a sequence of related images at a predetermined viewing distance;   determining most popular identified areas of interest that comprises less than all of the plurality of identified areas of interest; and   encoding the most popular identified areas of interest at a first quality level and unidentified areas of the image at a second and lower quality level than the most popular identified areas to produce a compressed copy of each image.   
   
   
       2 . A digital image compression system comprising:
 means for identifying a plurality of areas of interest in a sequence of related images provided by a display at a predetermined viewing distance;   means for determining most popular identified areas of interest that comprise less than all of the plurality of identified areas of interest; and   an encoder adapted to encode the most popular identified areas of interest at a first quality level, and unidentified areas of the image at a second and lower quality level than the most popular identified areas to produce a compressed copy of each image.