Brightness adjustment method

Abstract

A brightness adjustment method. An image of a scene is provided. The image is segmented into a plurality of areas, where each area has a plurality of pixels. One of the areas is selected as a transition area, and a transition brightness of the transition area is defined. The brightness of each remaining area of the image is also defined and compared to the transition brightness. According to the comparison result, the remaining areas are grouped into a plurality of regions, and a coefficient is determined for each region. The rightness of each pixel of the areas in each region is then adjusted by the corresponding coefficient.

What is claimed is:  
     
         1 . A brightness adjustment method, comprising: 
 providing a scene of which an image is to be captured;    segmenting the image into a plurality of areas, each area comprising a plurality of pixels;    selecting one of the areas as a transition area and defining a transition brightness of the transition area;    defining brightness of each remaining area of the image;    comparing the brightness of the remaining areas to the transition brightness;    grouping the remaining areas into a plurality of regions in response to the results of the comparing step;    determining a coefficient for each region; and    adjusting brightness of each pixel of the remaining areas in each region by the corresponding coefficient.    
     
     
         2 . The method according to  claim 1 , further comprises using an image capture device to capture the image.  
     
     
         3 . The method according to  claim 1 , further comprises using a charged-coupled device to capture the image.  
     
     
         4 . The method according to  claim 1 , wherein the step of selecting the transition area further comprises selecting the transition area from one area of the image mapping a predetermined element of the scene.  
     
     
         5 . The method according to  claim 1 , wherein the step of selecting the transition area further comprises selecting the transition area from one area of the image located in a predetermined position.  
     
     
         6 . The method according to  claim 1 , wherein the step of selecting the transition area further comprises selecting the transition area from one area of the image with a brightness closest to a predetermined brightness value.  
     
     
         7 . The method according to  claim 1 , wherein the step of defining the transition brightness further comprises computing an average brightness of the pixels of the transition area.  
     
     
         8 . The method according to  claim 1 , wherein the step of defining the transition brightness further comprises determining a percentage of a peak brightness among the pixels of the transition area.  
     
     
         9 . The method according to  claim 1 , wherein the step of defining the transition brightness further comprises selecting a medium brightness among the pixels of the transition area.  
     
     
         10 . The method according to  claim 1 , wherein the step of grouping the remaining areas further comprises grouping the remaining areas into a higher region and a lower region, wherein the areas in the higher region have brightness higher than the transition brightness, and the areas in the lower region have brightness lower than the transition brightness.  
     
     
         11 . The method according to  claim 10 , wherein the step of determining the coefficient further comprising determining a first coefficient for the lower region and a second coefficient for the higher region.  
     
     
         12 . The method according to  claim 11 , wherein the brightness of each pixel of each area in the lower region is adjusted by multiplying the first coefficient.  
     
     
         13 . The method according to  claim 11 , wherein the brightness of each pixel of each area in the higher region is adjusted by multiplying the second coefficient and then adding a constant.  
     
     
         14 . A brightness adjustment method, comprising: 
 providing an image of a scene;    segmenting the image into a plurality of areas, each area comprising a plurality of pixels of three primary colors;    selecting one of the areas as a transition area, and defining a transition brightness of the transition area;    comparing brightness of each area to the transition brightness to determine an adjustment coefficient for each area; and    adjusting brightness of the pixels of at least one color in at least one area by the corresponding adjustment coefficient.    
     
     
         15 . The method according to  claim 14 , wherein the step of selecting the transition area further comprises selecting the transition area from one area of the image mapping a predetermined element of the scene.  
     
     
         16 . The method according to  claim 14 , wherein the step of selecting the transition area further comprises selecting the transition area from one area of the image with a brightness closest to a predetermined brightness value.  
     
     
         17 . The method according to  claim 14 , wherein the step of defining the transition brightness further comprises computing an average brightness of the pixels of the transition area.  
     
     
         18 . The method according to  claim 14 , wherein the step of defining the transition brightness further comprises determining a percentage of a peak brightness among the pixels of the transition area.  
     
     
         19 . The method according to  claim 14 , further comprising the step of filtering brightness of the pixels of the remaining colors in the area adjusted by the adjustment coefficient.  
     
     
         20 . The method according to  claim 19 , wherein the step of filtering brightness of the pixels of the remaining colors includes multiplying the brightness of the pixels of the remaining colors by another coefficient.  
     
     
         21 . The method according to  claim 20 , wherein the step of filtering brightness of the pixels of the remaining colors includes displaying the adjusted pixels only.  
     
     
         22 . A brightness adjustment method, comprising: 
 providing an image of a scene;    segmenting the image into a plurality of areas, each area comprising a plurality of pixels of three primary colors;    selecting one of the areas as a transition area, and defining a transition brightness of the transition area;    comparing brightness of the remaining areas to the transition brightness to determine one adjustment coefficient for the pixels of each color in each of the remaining areas; and    adjusting brightness of the pixels of each color in at least one area by the corresponding adjustment coefficient.