Restoration of Color Components in an Image Model

Abstract

This invention relates to a method for improving image quality of a digital image captured with an imaging module comprising at least imaging optics and an image sensor, where the image is formed through the imaging optics, the image consisting of at least one colour component. In the method, the degradation information of each colour component of the image is found and is used for improving image quality. The degradation information of each colour component is specified by a point-spread function. Each colour component is restored by the degradation function. The image can be unprocessed image data. The invention also relates to several alternatives for implementing the restoration, and for controlling and regularizing the inverse process independently of the image degradation. The invention also relates to a device, to a module, to a system and to a computer program products and to a program modules.

1 . A method for developing a model for improving image quality of a digital image comprising:
 finding degradation information of each of at least one colour component of said image,   obtaining a degradation function according to the degradation information, and   restoring said each colour component by said degradation function.   
   
   
       2 . The method according to  claim 1 , wherein a regularization control is applied to the restored colour components. 
   
   
       3 . (canceled) 
   
   
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       9 . (canceled) 
   
   
       10 . A model for improving image quality of a digital image, said model being obtainable by a method as claimed in  claim 1 . 
   
   
       11 . A use of a model according to  claim 10  for improving the image quality of a digital image. 
   
   
       12 . A method for improving image quality of a digital image comprising:
 finding degradation information of each of at least one colour component of the image,   obtaining a degradation function according to the degradation information, and   restoring said each colour component by said degradation function.   
   
   
       13 . The method according to  claim 12 , wherein a regularization control is applied to the restored colour components. 
   
   
       14 . The method according to  claim 12 , wherein said degradation information of each colour component is found by a point-spread function. 
   
   
       15 . The method according to  claim 14 , wherein the restoration is implemented by an iterative restoration function being determined from the point-spread function of each colour component. 
   
   
       16 . The method according to  claim 12 , wherein the restoration is implemented by an iterative restoration function where at each iteration a one step de-blurring method with regularization is implemented. 
   
   
       17 . The method according to  claim 12 , wherein said image is unprocessed image data, wherein said restored colour components are further processed by other image reconstruction algorithms. 
   
   
       18 . The method according to  claim 12 , wherein one of the following colour systems is used: red, green, blue; hue, saturation, value; cyan, magenta, yellow, blue; luminance, chrominance. 
   
   
       19 . The method according to  claim 13 , wherein the regularization control is implemented into the de-blurring method for obtaining a de-blurred image. 
   
   
       20 . The method according to  claim 19 , wherein overshooting pixels are detected by a first and a second threshold values. 
   
   
       21 . A method for restoration of an image, wherein the restoration is implemented by an iterative restoration function where at each iteration a de-blurring method with regularization is implemented. 
   
   
       22 . The method according to  claim 21 , wherein a regularization control is applied to the restored colour components. 
   
   
       23 . The method according to  claim 21 , wherein the regularization control is implemented into the de-blurring method for obtaining a de-blurred image. 
   
   
       24 . The method according to  claim 21 , wherein overshooting pixels are detected by a first and a second threshold values. 
   
   
       25 . An apparatus for determining a model for improving image quality of a digital image comprising:
 a control unit configured for finding degradation information of each of at least one colour component of the image,   said control unit configured for obtaining a degradation function according to the degradation information, and   said control unit further configured for restoring said each colour component by said degradation function.   
   
   
       26 . The apparatus according to  claim 25 , wherein the control unit is further configured for applying regularization control during the restoration. 
   
   
       27 . The apparatus according to  claim 25 , wherein the control unit is further configured for further processing said image by other image reconstruction algorithms. 
   
   
       28 . The apparatus according to  claim 25  being capable of utilizing one of the following colour systems: red, green, blue; hue, saturation, value; cyan, magenta, yellow, blue; luminance, chrominance. 
   
   
       29 . The apparatus according to  claim 26 , wherein for the regularization control, said system control unit is further configured for de-blurring the restored image. 
   
   
       30 . An imaging module comprising imaging optics and an image sensor for forming an image through the imaging optics onto the light sensitive image sensor wherein a model for improving image quality as claimed in  claim 10  is related to said imaging module. 
   
   
       31 . The imaging module according to  claim 30 , wherein a control unit is further configured for applying regularization control during the restoration. 
   
   
       32 . A device comprising an imaging module as claimed in  claim 30 . 
   
   
       33 . The device according to  claim 32  being a mobile device equipped with communication capabilities. 
   
   
       34 . A program module for improving image quality in a device comprising an imaging module, said program module comprising a control unit configured for:
 finding a degradation information of each colour component of the image,   obtaining a degradation function according to the degradation information, and   restoring said each colour component by said degradation function.   
   
   
       35 . The program module according to  claim 34 , wherein the control unit further comprises instructions for applying regularization control during the restoration. 
   
   
       36 . (canceled) 
   
   
       37 . (canceled) 
   
   
       38 . A computer program product for improving image quality comprising computer implemented instructions stored on a readable medium, said instructions when executed by a processor for
 finding degradation information of each colour component of the image,   obtaining a degradation function according to the degradation information, and   restoring said each colour component by said degradation function.   
   
   
       39 . The computer program product according to  claim 38 , further comprising instructions for applying regularization control during the restoration. 
   
   
       40 . A computer program product for a restoration of an image, comprising computer readable instructions for implementing a de-blurring with regularization at each iteration of an iterative restoration. 
   
   
       41 . The computer program product according to  claim 40 , further comprising instructions for detecting overshooting pixels by a first and a second threshold values. 
   
   
       42 . An apparatus for determining a model for improving image quality of a digital image comprising:
 means for finding degradation information of each of at least one colour component of the image,   means for obtaining a degradation function according to the degradation information, and   means for restoring said each colour component by said degradation function.   
   
   
       43 . The apparatus according to  claim 42 , further comprising:
 means for applying regularization control during the restoration.