Lossy/lossless region-of-interest image coding

Abstract

A method and apparatus for encoding digital image data wherein region of interest can be specified either before the encoding process has begun or during the encoding process ( 127 ), such that the priority of the encoder outputs are modified so as to place more emphasis on the region of interest, therefore increasing the speed and/or increasing the fidelity of the reconstructed region of interest. The system, therefore, enables more effective reconstruction of digital images over communication lines ( 128 ).

1 - 20 . (canceled)  
   
   
       21 . A method of image compression, said method comprising the steps of: 
 selecting a region of interest of the image represented by digital image data;    shifting bits of transform coefficients corresponding to the digital image data of the selected image by a variable amount;    outputting said digital image data corresponding to said shifted bits of transform coefficients being output earlier than the digital image data corresponding to areas outside of the region of interest.    
   
   
       22 . A method of image compression, said method comprising the steps of: 
 selecting a region of interest of the image represented by digital image data;    shifting bits of transform coefficients corresponding to the digital image data of the selected image by a variable amount;    outputting said digital image data corresponding to large shifted bits of transform coefficients earlier than less shifted bits of transform coefficients.    
   
   
       23 . The method of image compression according to  claim 21  or  22 , 
 said variable amount corresponds to the order of coding transform coefficients.    
   
   
       24 . The method of image compression according to  claim 21  or  22 , 
 said variable amount varies each selected region of interest.    
   
   
       25 . The method of image compression according to  claim 21 , 
 the larger the variable amount, the earlier in the digital image data the transform coefficients are placed.    
   
   
       26 . A method of image compression, said method comprising the steps of: 
 selecting a region of interest of the image represented by digital image data;    outputting the information of said selected region of interest, the information used for identifying said selected region of interest,    wherein bits of transform coefficients corresponding to the digital image data of the selected region of interest are shifted by a predetermined amount, said predetermined amount corresponding to a desired scale-up rate.    
   
   
       27 . The method of image compression according to  claim 26 , wherein 
 said digital image data corresponding to said shifted bits of transform coefficients being output earlier than the digital image data corresponding to areas outside of the region of interest.