Format conversion

Abstract

A method and computer program product for reformatting at least a portion of a digital source image. The digital source image has a number of pixels defining an original format which is to be converted to a destination image in a new format having a number of pixels. The number of pixels of the new format is greater than the number of pixels in the original format. A gradient is estimated at a point within a window which encompasses a plurality of intensity values from the source image. A polynomial is then used to determine a value for the point in the new format within the window. The polynomial is based in part upon the gradient. Values are then determined for additional points in the destination image by selecting a new window and repeating the acts of estimating a gradient and using a polynomial to determine a value.

1 . A method for reformatting a digital source image having a number of pixels defining an original format to a destination image in a new format having a number of pixels, wherein the number of pixels of the new format is greater than the number of pixels in the original format, the method comprising: 
 upconverting the number of pixels in the original format to the number of pixels in the new format using a filter selected from a plurality of filters, wherein selection of the filter at a pixel location within the new format depends on an image intensity surface near the pixel location within the new format.    
     
     
         2 . The method according to  claim 1 , wherein the digital source image is a digital video image.  
     
     
         3 . The method according to  claim 2 , wherein the digital video image is part of a set of digital video images.  
     
     
         4 . The method according to  claim 3 , wherein the step of upconverting is performed on all of the digital video images in the set of digital video images.  
     
     
         5 . The method according to  claim 1 , wherein the method is performed on a computer processor.  
     
     
         6 . The method according to  claim 1 , wherein the filter is a space-variant approximation.  
     
     
         7 . A method for reformatting a digital image having a number of pixels having associated digital data, the digital image having an associated length, width and aspect ratio defining an original format to a destination image having a number of pixels, the destination image having an associated length, width and aspect ratio defining a new format, wherein the number of pixels of the new format is greater than the number of pixels in the original format, the method comprising: 
 normalizing the aspect ratio of the original image to that of the destination image; and    adaptively filtering the digital data for each pixel using a filter selected from a plurality of filters based upon an image intensity surface near each pixel to produce new digital data for each pixel in the new format.    
     
     
         8 . A method for reformatting a digital image having a number of pixels having associated digital data, the digital image having an associated length, width and aspect ratio defining an original format to a destination image having a number of pixels, the destination image having an associated length, width and aspect ratio defining a new format, wherein the number of pixels of the new format is greater than the number of pixels in the original format, the method comprising: 
 normalizing the aspect ratio of the original image to that of the destination image; and    adaptively filtering the digital data for each pixel using a filter selected from a plurality of filters based upon an image intensity surface near each pixel to produce new digital data for each new pixel in the new format.    
     
     
         9 . A computer program product for use on a computer system for reformatting a digital image having a number of pixels defining an original format to a new format having a number of pixels, wherein the number of pixels of the new format is greater than the number of pixels in the original format, the computer program product comprising a computer usable medium having computer readable program code thereon, the computer readable program code comprising: 
 computer code for upconverting the number of pixels in the original format to the number of pixels in the new format using a filter, wherein selection of the filter from a plurality of filters for a pixel location within the new format depends on an image intensity surface near the pixel location.    
     
     
         10 . A computer program product according to  claim 9 , wherein the filter is a space-variant approximation.