Method for reducing motion blur in a digital image

Abstract

A method for reducing motion blur in a digital image is disclosed. An embodiment of the method comprises increasing the magnitude of the amplitude of the signals in a preselected set of spatial frequencies of the image in the direction of the motion blur.

1 . A method for reducing motion blur in a digital image, said method comprising increasing the magnitude of the amplitude of the signals in a preselected set of spatial frequencies of the image in the direction of the motion blur.  
   
   
       2 . The method of  claim 1 , wherein said signals are sinusoidal signals and wherein said spatial frequencies are derived via a Fourier transform.  
   
   
       3 . The method of  claim 1  and further comprising determining the direction of motion blur.  
   
   
       4 . The method of  claim 3 , wherein said determining the direction of motion blur comprises: 
 providing image data representative of at least a portion of said digital image;    analyzing said image data to calculate a first figure of merit of said digital image in a first direction;    analyzing said image data to calculate a second figure of merit of said digital image in a second direction, said first and said second directions being substantially orthogonal;    calculating a first ratio of said first figure of merit to said second figure of merit, said ratio being the greater of said first or second figure of merit divided by the lesser of said first or second figure of merit; and    comparing said first ratio to a preselected value, wherein motion blur exists in said digital image if said first ratio is greater than said preselected value.    
   
   
       5 . The method of  claim 3 , wherein said determining the direction of motion blur comprises: 
 providing image data representative of at least a portion of said digital image;    analyzing said image data to calculate a plurality of first figures of merit of said digital image in a plurality of directions;    analyzing said image data to calculate a plurality of second figures of merit of said digital image, wherein each of said second figures of merit is in a direction substantially orthogonal to a corresponding first figure of merit;    calculating a plurality of ratios of said first figures of merit to their corresponding second figures of merit, each of said ratios being the greater of a first or second figure of merit divided by the lesser of its corresponding first or second figure of merit; and    comparing said ratios to a preselected value, wherein motion blur exists in said digital image if one of said ratios is greater than said preselected value.    
   
   
       6 . An apparatus for reducing motion blur in an image, said apparatus comprising a computer and a computer-readable medium operatively associated with said computer, said computer-readable medium containing instructions for controlling said computer to reduce motion blur in an image by: 
 determining the direction of motion blur by analyzing image data representative of at least a portion of said image; and    increasing the magnitude of the amplitude of spatial frequency in the direction of said motion blur.    
   
   
       7 . The apparatus of  claim 6 , wherein said increasing the magnitude of the amplitude of spatial frequency comprises increasing the magnitude of the amplitude of the signals in a preselected set of spatial frequencies of the image in the direction of the motion blur.  
   
   
       8 . The apparatus of  claim 6 , wherein said increasing the magnitude of the amplitude of spatial frequency comprises increasing the magnitude of the amplitude of the sinusoidal signals in a preselected set of spatial frequencies of the image in the direction of the motion blur, wherein said spatial frequencies are derived by way of a Fourier transform.  
   
   
       9 . The apparatus of  claim 8 , wherein said image data is transformed back to the spatial domain by an inverse Fourier transform.  
   
   
       10 . The apparatus of  claim 6 , wherein said determining the direction of motion blur comprises: 
 analyzing said image data to calculate a first figure of merit of said digital image in a first direction;    analyzing said image data to calculate a second figure of merit of said digital image in a second direction, said first and said second directions being substantially orthogonal;    calculating a first ratio of said first figure of merit to said second figure of merit, said ratio being the greater of said first or second figure of merit divided by the lesser of said first or second figure of merit; and    comparing said first ratio to a preselected value, wherein motion blur exists in said digital image if said first ratio is greater than said preselected value.    
   
   
       11 . The apparatus of  claim 6 , wherein said determining the direction of motion blur comprises: 
 analyzing said image data to calculate a plurality of first figures of merit of said digital image in a plurality of directions;    analyzing said image data to calculate a plurality of second figures of merit of said digital image, wherein each of said second figures of merit is in a direction substantially orthogonal to a corresponding first figure of merit;    calculating a plurality of ratios of said first figures of merit to their corresponding second figures of merit, each of said ratios being the greater of a first or second figure of merit divided by the lesser of its corresponding first or second figure of merit; and    comparing said ratios to a preselected value, wherein motion blur exists in said digital image if one of said ratios is greater than said preselected value.    
   
   
       12 . A method for reducing motion blur in an image, said method comprising: 
 providing image data representative of at least a portion of said image;    analyzing said image data to detect the presence of motion blur in said image;    analyzing said image data to detect the direction of motion blur in said digital image;    processing said image data to increase edge acuity said image in said direction of said motion blur.    
   
   
       13 . The method of  claim 12 , wherein said analyzing said image data to detect the presence of motion blur comprises: 
 analyzing said image data to calculate a first figure of merit of said digital image in a first direction;    analyzing said image data to calculate a second figure of merit of said digital image in a second direction, said first and said second directions being substantially orthogonal;    calculating a first ratio of said first figure of merit to said second figure of merit, said ratio being the greater of said first or said second figure of merit divided by the lesser of said first or said second figure of merit; and    comparing said first ratio to a preselected value, wherein motion blur exists in said digital image if said first ratio is greater than said preselected value.    
   
   
       14 . The method of  claim 13 , wherein said analyzing said image data to detect the direction of motion blur comprises determining the lowest value of said first and said second figures of merit, said lowest value corresponding to said direction of motion blur.  
   
   
       15 . The method of  claim 12 , wherein said analyzing said image data to detect the presence of motion blur comprises: 
 analyzing said image data to calculate a plurality of first figures of merit of said digital image in a plurality of directions;    analyzing said image data to calculate a plurality of second figures of merit of said digital image, wherein each of said second figures of merit is in a direction substantially orthogonal to a corresponding first figure of merit;    calculating a plurality of ratios of said first figures of merit to their corresponding second figures of merit, each of said ratios being the greater of a first or second figure of merit divided by the lesser of its corresponding first or second figure of merit; and    comparing said ratios to a preselected value, wherein motion blur exists in said digital image if one of said ratios is greater than said preselected value.    
   
   
       16 . The method of  claim 15 , wherein said analyzing said image data to detect the direction of motion blur comprises determining which of said ratios has the highest value and determining the lowest figure of merit of said highest valued ratio, said lowest figure of merit corresponding to said direction of motion blur.  
   
   
       17 . The method of  claim 12 , wherein said processing comprises increasing the magnitude of the amplitude of the signals in a preselected set of spatial frequencies of the transformed image data in the direction of the motion blur.  
   
   
       18 . The method of  claim 12 , wherein said processing comprises increasing the magnitude of the amplitude of the sinusoidal signals in a preselected set of spatial frequencies of the transformed image data in the direction of the motion blur, wherein said image data is transformed by a Fourier transform.  
   
   
       19 . The method of  claim 18 , and further comprising transforming said image data back to the spatial domain by an inverse Fourier transform.  
   
   
       20 . The method of  claim 12 , wherein said processing comprises increasing the amplitude of signals of said image based on the detection and amplitude of motion blur.