Patent Publication Number: US-7714900-B2

Title: Color interpolation processing method

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates to a processing method, and more particularly to a color interpolation processing method. 
   2. Description of the Related Art 
     FIG. 1   a  shows a structure for an image sensor module. Scene is captured by lens  11 . A color filter array (CFA)  12  comprises color filters R, B, and G for acquiring color components. A charged-coupled device (CCD)  13  or an active pixel sensor (APS) comprises a plurality of pixel units. Each pixel unit transforms color components into electronic signals and stores the electronic signals. 
   One color component is acquired by one color filter. Thus, only one color component is available in each pixel unit such that the other two of the three color components are missing from each pixel unit. To completely display the scene  10 , various color interpolation methods are utilized. The color interpolation methods determine the other two missing color components according to the filtered and stored color component. 
   One color interpolation method by S. C.Pei et al in IEEE Trans. Circuits and Systems for Video Technology, VOL. 13, NO. 6, June 2003 describes “Effective Color Interpolation in CCD Color Filter Arrays Using Signal Correlation”. 
     FIG. 1   b  is a schematic diagram of the CFA. The color interpolation method disclosed by S. C. Pei et al obtains a missing G7 value according to a known R7 value. The missing G7 value can be recovered as (1). 
   
     
       
         
           
             
               
                 
                   G 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   7 
                 
                 = 
                 
                   
                     R 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     7 
                   
                   + 
                   
                     
                       1 
                       4 
                     
                     ⁢ 
                     
                       ( 
                       
                         
                           
                             K 
                             R 
                           
                           ⁢ 
                           3 
                         
                         + 
                         
                           
                             K 
                             R 
                           
                           ⁢ 
                           6 
                         
                         + 
                         
                           
                             K 
                             R 
                           
                           ⁢ 
                           8 
                         
                         + 
                         
                           
                             K 
                             R 
                           
                           ⁢ 
                           11 
                         
                       
                       ) 
                     
                   
                 
               
             
             
               
                 ( 
                 1 
                 ) 
               
             
           
         
       
     
   
   wherein, K R 3 is defined as in (2), K R 6 is defined as in (3), K R 8 is defined as in (4), and K R 11 is defined as in (5). 
   
     
       
         
           
             
               
                 
                   
                     K 
                     R 
                   
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                   3 
                 
                 = 
                 
                   
                     
                       G 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       3 
                     
                     - 
                     
                       R 
                       ⁢ 
                       
                           
                       
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                       3 
                     
                   
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                       G 
                       ⁢ 
                       
                           
                       
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                       3 
                     
                     - 
                     
                       
                         1 
                         2 
                       
                       ⁢ 
                       
                         ( 
                         
                           
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                             ⁢ 
                             
                                 
                             
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                             1 
                           
                           + 
                           
                             R 
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                             7 
                           
                         
                         ) 
                       
                     
                   
                 
               
             
             
               
                 ( 
                 2 
                 ) 
               
             
           
           
             
               
                 
                   
                     K 
                     R 
                   
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                   6 
                 
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                       ⁢ 
                       
                           
                       
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                       6 
                     
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                       R 
                       ⁢ 
                       
                           
                       
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                       6 
                     
                   
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                       G 
                       ⁢ 
                       
                           
                       
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                       6 
                     
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                         1 
                         2 
                       
                       ⁢ 
                       
                         ( 
                         
                           
                             R 
                             ⁢ 
                             
                                 
                             
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                             5 
                           
                           + 
                           
                             R 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             7 
                           
                         
                         ) 
                       
                     
                   
                 
               
             
             
               
                 ( 
                 3 
                 ) 
               
             
           
           
             
               
                 
                   
                     K 
                     R 
                   
                   ⁢ 
                   8 
                 
                 = 
                 
                   
                     
                       G 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       8 
                     
                     - 
                     
                       R 
                       ⁢ 
                       
                           
                       
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                       8 
                     
                   
                   = 
                   
                     
                       G 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       8 
                     
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                         1 
                         2 
                       
                       ⁢ 
                       
                         ( 
                         
                           
                             R 
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                             7 
                           
                           + 
                           
                             R 
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                             9 
                           
                         
                         ) 
                       
                     
                   
                 
               
             
             
               
                 ( 
                 4 
                 ) 
               
             
           
           
             
               
                 
                   
                     K 
                     R 
                   
                   ⁢ 
                   11 
                 
                 = 
                 
                   
                     
                       G 
                       ⁢ 
                       
                           
                       
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                       11 
                     
                     - 
                     
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                       ⁢ 
                       
                           
                       
                       ⁢ 
                       11 
                     
                   
                   = 
                   
                     
                       G 
                       ⁢ 
                       
                           
                       
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                       11 
                     
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                         1 
                         2 
                       
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                         ( 
                         
                           
                             R 
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                             7 
                           
                           + 
                           
                             R 
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                             13 
                           
                         
                         ) 
                       
                     
                   
                 
               
             
             
               
                 ( 
                 5 
                 ) 
               
             
           
         
       
     
   
   A missing B7 value can be obtained according to the missing G7 value defined by (1). The missing B7 value is calculated as 
   
     
       
         
           
             
               
                 
                   B 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   7 
                 
                 = 
                 
                   
                     G 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     7 
                   
                   + 
                   
                     
                       1 
                       4 
                     
                     ⁢ 
                     
                       ( 
                       
                         
                           
                             K 
                             B 
                           
                           ⁢ 
                           2 
                         
                         + 
                         
                           
                             K 
                             B 
                           
                           ⁢ 
                           4 
                         
                         + 
                         
                           
                             K 
                             B 
                           
                           ⁢ 
                           10 
                         
                         + 
                         
                           
                             K 
                             B 
                           
                           ⁢ 
                           12 
                         
                       
                       ) 
                     
                   
                 
               
             
             
               
                 ( 
                 6 
                 ) 
               
             
           
         
       
     
   
   wherein operations of K B 2, K B 4, K B 10, and K B 12 are similar to K R 3, K R 6, K R 8, and K R 11. 
   Although the missing value is obtained by the color interpolation method disclosed by S. C. Pei et al, the color interpolation method does not particularly take the edge pattern into account. Therefore, the method would induce the false colors and blur the pattern around the edges. 
   Another color interpolation method by X.Wang et al in ICICS-PCM 2003 describes “Edge-Adaptive Color Reconsruction for Single-Sensor Digital Camera”. 
   The color interpolation method disclosed by X. Wang et al detects an edge pattern in a G channel and calculates a G value at R or B pixel in the edge pattern. Next, the color interpolation method utilizes a weighted method to calculate an absolute difference value between a horizontal direction of the G channel and a vertical direction of the G channel for obtaining an R value at an unknown R pixel and a B value at an unknown B pixel. 
   The color interpolation method disclosed by X. Wang et al usually detects the incorrect edge pattern such that the incorrect value is generated. Additionally, since the weighted method is more complex, the cost of the hardware is increased. 
   Another color interpolation method by Y. M. Wu et al in Image Analysis and Interpretation, 2004. 6th IEEE Southwest Symposium describes “Color Interpolation for Single CCD Color Camera”. The color interpolation method utilizes a weighted method to calculate the unknown G, B, R values. The accuracy is higher, however, the cost of the hardware is higher. 
   BRIEF SUMMARY OF THE INVENTION 
   Color interpolation processing methods are provided. A scene comprising at least of three preset color components is captured. A two-dimensional matrix is generated according to the scene. The two-dimensional matrix comprises a plurality of image detection components, each corresponding to one of the preset color components. A plurality of matrixes are generated according to the image detection components. Each matrix comprises a plurality of column color difference components or a plurality of row color difference components. The matrixes are divided into a first matrix module and a second matrix module. The column color difference components and the row color difference components among the first or among the second matrix module are calculated to obtain a plurality of operation values according to the corresponding preset color corresponded by a first image detection component among the image detection components. A minimum value among the operation values is determined and served as a minimum operation value. The matrix corresponding to the minimum operation value serves as a minimum color difference variation matrix (MCDVM). The column color difference components or the row color difference components of the MCDVM are calculated to obtain a minimum color difference variation according to the minimum operation value. An average value of the column or the row color difference components of the minimum color difference variation and the first image detection component are calculated to obtain the value of one of unknown color. 
   A detailed description is given in the following embodiments with reference to the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein: 
       FIG. 1   a  shows a structure for an image sensor module; 
       FIG. 1   b  is a schematic diagram of the CFA; 
       FIG. 2  is a flowchart of an exemplary embodiment of a color interpolation processing method; 
       FIG. 3   a  is a schematic diagram of a Bayer CFA; 
       FIG. 3   b  is a schematic diagram of the two-dimensional matrix; and 
       FIGS. 4   a ˜ 4   d  are schematic diagrams of matrixes. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 2  is a flowchart of an exemplary embodiment of a color interpolation processing method. A scene is captured by a capture device (step  210 ). In this embodiment, the capture device is an image sensor module. 
   A two-dimensional matrix is generated according to the captured scene (step  211 ). In this embodiment, a Bayer CFA  31  is shown as  FIG. 3   a  and filters color components from the captured scene to generate a two-dimensional matrix  32  as shown in  FIG. 3   b . The Bayer CFA  31  is given as an example, but the disclosure is not limited thereto. 
   The Bayer CFA  31  comprises color filters R, G, and B for filtering red components, green components, and blue components. A CCD or an APS comprises a plurality of pixel units for transmitting and storing the red component, green component, and blue component. Thus, the two-dimensional matrix  32 , as shown in  FIG. 3   b , is generated. Each pixel unit only stores one color component so that the other two color components are missed. The missing component is not limited to the red component, the green component, or the blue component. 
   Two-dimensional matrix  32  comprises image detection components R 00 ˜R 44 , G 01 ˜G 43 , and B 11 ˜B 33  representing the stored data. For example, image detection component R 00  shown in  FIG. 3   b  represents a color data stored in a pixel unit  320 . In this embodiment, image detection components R 00 ˜R 44 , G 01 ˜G 43 , and B 11 ˜B 33  respectively correspond to three colors components. For example, image detection components R 00 ˜R 44  correspond to the red components, image detection components G 01 ˜G 43  correspond to the green components, and image detection components B 11 ˜B 33  correspond to the blue components. 
   A plurality of matrixes are generated according to image detection components R 00 ˜R 44 , G 01 ˜G 43 , and B 11 ˜B 33  (step  212 ). Each matrix comprises a plurality of column color difference component and a plurality of row color difference component. In this embodiment, a matrix  41  shown in  FIG. 4   a  is generated by image detection components in odd-columns of two-dimensional matrix  32 , a matrix  42  shown in  FIG. 4   b  is generated by image detection components in even-rows of two-dimensional matrix  32 , a matrix  43  shown in  FIG. 4   c  is generated by image detection components in even-columns of two-dimensional matrix  32 , and a matrix  44  shown in  FIG. 4   d  is generated by image detection components in odd-rows of two-dimensional matrix  32 . 
   Generation of the matrixes  41 ˜ 44  shown in  FIGS. 4   a ˜ 4   d  is described in the following. Color difference components C 00 , C 10 , and C 20  in first column of matrix  41  are generated by image detection components R 00 , G 10 , R 20 , G 30 , and R 40  in first column of two-dimensional matrix  32 . The color difference components C 00 , C 10 , and C 20  can be recovered as (7)˜(9). 
   
     
       
         
           
             
               
                 
                   C 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   00 
                 
                 = 
                 
                   
                     
                       ( 
                       
                         
                           R 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           00 
                         
                         + 
                         
                           R 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           20 
                         
                       
                       ) 
                     
                     2 
                   
                   - 
                   
                     G 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     10 
                   
                 
               
             
             
               
                 ( 
                 7 
                 ) 
               
             
           
           
             
               
                 
                   C 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   10 
                 
                 = 
                 
                   
                     R 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     20 
                   
                   - 
                   
                     
                       ( 
                       
                         
                           G 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           10 
                         
                         + 
                         
                           G 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           30 
                         
                       
                       ) 
                     
                     2 
                   
                 
               
             
             
               
                 ( 
                 8 
                 ) 
               
             
           
           
             
               
                 
                   C 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   20 
                 
                 = 
                 
                   
                     
                       ( 
                       
                         
                           R 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           20 
                         
                         + 
                         
                           R 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           40 
                         
                       
                       ) 
                     
                     2 
                   
                   - 
                   
                     G 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     30 
                   
                 
               
             
             
               
                 ( 
                 9 
                 ) 
               
             
           
         
       
     
   
   Color difference components C 01 , C 11 , and C 21  in the second column of matrix  41  are generated by image detection components R 02 , G 12 , R 22 , G 32 , and R 42  in the third column of two-dimensional matrix  32 . Color difference components C 02 , C 12 , and C 22  in the third column of matrix  41  are generated by image detection components R 04 , G 14 , R 24 , G 34 , and R 44  in fifth column of two-dimensional matrix  32 . Since the operations of the color difference components C 01 , C 11 , and C 21  in the second column of matrix  41  and color difference components C 02 , C 12 , and C 22  in the third columns of matrix  41  are similar to that of the color difference components C 00 , C 10 , and C 20  in first column of matrix  41 , descriptions of color difference components C 01 , C 11 , C 21 , C 02 , C 12 , and C 22  are omitted. 
   Color difference components D 00 , D 01 , and D 02  in the first row of matrix  42  are generated by image detection components G 10 , B 11 , G 12 , B 13 , and G 14  in the second row of two-dimensional matrix  32 . The color difference components D 00 , D 01 , and D 02  can be recovered as (10)˜(12). 
   
     
       
         
           
             
               
                 
                   D 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   00 
                 
                 = 
                 
                   
                     B 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     11 
                   
                   - 
                   
                     
                       ( 
                       
                         
                           G 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           10 
                         
                         + 
                         
                           G 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           12 
                         
                       
                       ) 
                     
                     2 
                   
                 
               
             
             
               
                 ( 
                 10 
                 ) 
               
             
           
           
             
               
                 
                   D 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   01 
                 
                 = 
                 
                   
                     
                       ( 
                       
                         
                           B 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           11 
                         
                         + 
                         
                           B 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           13 
                         
                       
                       ) 
                     
                     2 
                   
                   - 
                   
                     G 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     12 
                   
                 
               
             
             
               
                 ( 
                 11 
                 ) 
               
             
           
           
             
               
                 
                   D 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   02 
                 
                 = 
                 
                   
                     B 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     13 
                   
                   - 
                   
                     
                       ( 
                       
                         
                           G 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           12 
                         
                         + 
                         
                           G 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           14 
                         
                       
                       ) 
                     
                     2 
                   
                 
               
             
             
               
                 ( 
                 12 
                 ) 
               
             
           
         
       
     
   
   Color difference components D 20 , D 21 , and D 22  in third row of matrix  42  are generated by image detection components G 30 , B 31 , G 32 , B 33 , and G 34  in the fourth row of two-dimensional matrix  32 . Since the operations of color difference components D 20 , D 21 , and D 22  in the third row of matrix  42  are similar to that of color difference components D 00 , D 01 , and D 02  in the first row of matrix  42 , descriptions of color difference components D 20 , D 21 , and D 22  are omitted. 
   Color difference components E 00 , E 10 , and E 20  in first column of matrix  43  are generated by image detection components G 01 , B 11 , G 21 , B 31 , and G 41  in the second column of two-dimensional matrix  32 . The color difference components E 00 , E 10 , and E 20  can be recovered as (13)˜(15). 
   
     
       
         
           
             
               
                 
                   E 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   00 
                 
                 = 
                 
                   
                     B 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     11 
                   
                   - 
                   
                     
                       ( 
                       
                         
                           G 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           01 
                         
                         + 
                         
                           G 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           21 
                         
                       
                       ) 
                     
                     2 
                   
                 
               
             
             
               
                 ( 
                 13 
                 ) 
               
             
           
           
             
               
                 
                   E 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   10 
                 
                 = 
                 
                   
                     
                       ( 
                       
                         
                           B 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           11 
                         
                         + 
                         
                           B 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           31 
                         
                       
                       ) 
                     
                     2 
                   
                   - 
                   
                     G 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     21 
                   
                 
               
             
             
               
                 ( 
                 14 
                 ) 
               
             
           
           
             
               
                 
                   E 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   20 
                 
                 = 
                 
                   
                     B 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     31 
                   
                   - 
                   
                     
                       ( 
                       
                         
                           G 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           21 
                         
                         + 
                         
                           G 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           41 
                         
                       
                       ) 
                     
                     2 
                   
                 
               
             
             
               
                 ( 
                 15 
                 ) 
               
             
           
         
       
     
   
   Color difference components E 02 , E 12 , and E 22  in the third column of matrix  43  are generated by image detection components G 03 , B 13 , G 23 , B 33 , and G 43  in the fourth column of two-dimensional matrix  32 . Since the operations of color difference components E 02 , E 12 , and E 22  in the third column of matrix  43  are similar to that of color difference components E 00 , E 10 , and E 20  in first column of matrix  43 , descriptions of color difference components E 02 , E 12 , and E 22  are omitted. 
   Color difference components F 00 , F 01 , and F 02  in the first row of matrix  44  are generated by image detection components R 00 , G 01 , R 02 , G 03 , and R 04  in the first row of two-dimensional matrix  32 . The color difference components F 00 , F 01 , and F 02  can be recovered as (16)˜(18). 
   
     
       
         
           
             
               
                 
                   F 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   00 
                 
                 = 
                 
                   
                     
                       ( 
                       
                         
                           R 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           00 
                         
                         + 
                         
                           R 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           02 
                         
                       
                       ) 
                     
                     2 
                   
                   - 
                   
                     G 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     01 
                   
                 
               
             
             
               
                 ( 
                 16 
                 ) 
               
             
           
           
             
               
                 
                   F 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   01 
                 
                 = 
                 
                   
                     R 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     02 
                   
                   - 
                   
                     
                       ( 
                       
                         
                           G 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           01 
                         
                         + 
                         
                           G 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           03 
                         
                       
                       ) 
                     
                     2 
                   
                 
               
             
             
               
                 ( 
                 17 
                 ) 
               
             
           
           
             
               
                 
                   F 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   02 
                 
                 = 
                 
                   
                     
                       ( 
                       
                         
                           R 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           02 
                         
                         + 
                         
                           R 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           04 
                         
                       
                       ) 
                     
                     2 
                   
                   - 
                   
                     G 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     03 
                   
                 
               
             
             
               
                 ( 
                 18 
                 ) 
               
             
           
         
       
     
   
   Color difference components F 10 , F 11 , and F 12  in the second row of matrix  44  are generated by image detection components R 20 , G 21 , R 22 , G 23 , and R 24  in the third row of two-dimensional matrix  32 . Color difference components F 20 , F 21 , and F 22  in the third row of matrix  44  are generated by image detection components R 40 , G 41 , R 42 , G 43 , and R 44  in the fifth row of two-dimensional matrix  32 . Since the operations of color difference components F 10 , F 11 , and F 12  in the second row of matrix  44  and color difference components F 20 , F 21 , and F 22  in the third row of matrix  44  are similar to that of color difference components F 00 , F 01 , and F 02  in the first row of matrix  44 , descriptions of color difference components F 10 , F 11 , F 12 , F 20 , F 21 , and F 22  are omitted. 
   Matrixes  41 ˜ 44  are divided into a first matrix module and a second matrix module (step  213 ). In this embodiment, since image detection components in odd columns and in odd rows of two-dimensional matrix  32  correspond to red components and green components, and matrixes  41  and  44  are generated by image detection components in odd columns and in odd rows of two-dimensional matrix  32 , matrixes  41  and  44  are divided into the first matrix group. 
   Additionally, since image detection components in even columns and in even rows of two-dimensional matrix  32  correspond to blue components and green components and matrixes  42  and  43  are generated by image detection components in even columns and in even rows of two-dimensional matrix  32 , matrixes  42  and  43  are divided into the second matrix group. 
   The corresponding matrixes among the first matrix module or the second matrix module are calculated according to a first image detection component among the image detection components of two-dimensional matrix  32  to obtain various operation values (step  214 ). Since the image detection component R 22  stored in a pixel unit  321  corresponds to red component, the missing components G 22  and B 22  could be obtained by calculating matrixes  41  and  44  as followed. 
   First, an average value C_V 0  of first column color difference components of matrix  41  can be recovered as (19), an average value C_V 1  of second column color difference components of matrix  41  can be recovered as (20), an average value C_V 2  of third column color difference components of matrix  41  can be recovered as (21), an average value C_H 0  of first row color difference components of matrix  41  can be recovered as (22), an average value C_H 1  of second row color difference components of matrix  41  can be recovered as (23), and an average value C_H 2  of third row color difference components of matrix  41  can be recovered as (24). 
   
     
       
         
           
             
               
                 
                   C_V 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   0 
                 
                 = 
                 
                   
                     
                       C 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       00 
                     
                     + 
                     
                       C 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       10 
                     
                     + 
                     
                       C 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       20 
                     
                   
                   3 
                 
               
             
             
               
                 ( 
                 19 
                 ) 
               
             
           
           
             
               
                 
                   C_V 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   1 
                 
                 = 
                 
                   
                     
                       C 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       01 
                     
                     + 
                     
                       C 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       11 
                     
                     + 
                     
                       C 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       21 
                     
                   
                   3 
                 
               
             
             
               
                 ( 
                 20 
                 ) 
               
             
           
           
             
               
                 
                   C_V 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   2 
                 
                 = 
                 
                   
                     
                       C 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       02 
                     
                     + 
                     
                       C 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       12 
                     
                     + 
                     
                       C 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       22 
                     
                   
                   3 
                 
               
             
             
               
                 ( 
                 21 
                 ) 
               
             
           
           
             
               
                 
                   C_H 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   0 
                 
                 = 
                 
                   
                     
                       C 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       00 
                     
                     + 
                     
                       C 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       01 
                     
                     + 
                     
                       C 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       02 
                     
                   
                   3 
                 
               
             
             
               
                 ( 
                 22 
                 ) 
               
             
           
           
             
               
                 
                   C_H 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   1 
                 
                 = 
                 
                   
                     
                       C 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       10 
                     
                     + 
                     
                       C 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       11 
                     
                     + 
                     
                       C 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       12 
                     
                   
                   3 
                 
               
             
             
               
                 ( 
                 23 
                 ) 
               
             
           
           
             
               
                 
                   C_H 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   2 
                 
                 = 
                 
                   
                     
                       C 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       20 
                     
                     + 
                     
                       C 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       21 
                     
                     + 
                     
                       C 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       22 
                     
                   
                   3 
                 
               
             
             
               
                 ( 
                 24 
                 ) 
               
             
           
         
       
     
   
   Next, an average value F_V 0  of first column color difference components of matrix  44  can be recovered as (25), an average value F_V 1  of second column color difference components of matrix  44  can be recovered as (26), an average value F_V 2  of third column color difference components of matrix  44  can be recovered as (27), an average value F _H 0  of first row color difference components of matrix  44  can be recovered as (28), an average value F_H 1  of second row color difference components of matrix  44  can be recovered as (29), and an average value F_H 2  of third row color difference components of matrix  44  can be recovered as (30). 
   
     
       
         
           
             
               
                 
                   F_V 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   0 
                 
                 = 
                 
                   
                     
                       F 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       00 
                     
                     + 
                     
                       F 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       10 
                     
                     + 
                     
                       F 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       20 
                     
                   
                   3 
                 
               
             
             
               
                 ( 
                 25 
                 ) 
               
             
           
           
             
               
                 
                   F_V 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   1 
                 
                 = 
                 
                   
                     
                       F 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       01 
                     
                     + 
                     
                       F 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       11 
                     
                     + 
                     
                       F 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       21 
                     
                   
                   3 
                 
               
             
             
               
                 ( 
                 26 
                 ) 
               
             
           
           
             
               
                 
                   F_V 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   2 
                 
                 = 
                 
                   
                     
                       F 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       02 
                     
                     + 
                     
                       F 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       12 
                     
                     + 
                     
                       F 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       22 
                     
                   
                   3 
                 
               
             
             
               
                 ( 
                 27 
                 ) 
               
             
           
           
             
               
                 
                   F_H 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   0 
                 
                 = 
                 
                   
                     
                       F 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       00 
                     
                     + 
                     
                       F 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       01 
                     
                     + 
                     
                       F 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       02 
                     
                   
                   3 
                 
               
             
             
               
                 ( 
                 28 
                 ) 
               
             
           
           
             
               
                 
                   F_H 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   1 
                 
                 = 
                 
                   
                     
                       F 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       10 
                     
                     + 
                     
                       F 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       11 
                     
                     + 
                     
                       F 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       12 
                     
                   
                   3 
                 
               
             
             
               
                 ( 
                 29 
                 ) 
               
             
           
           
             
               
                 
                   F_H 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   2 
                 
                 = 
                 
                   
                     
                       F 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       20 
                     
                     + 
                     
                       F 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       21 
                     
                     + 
                     
                       F 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       22 
                     
                   
                   3 
                 
               
             
             
               
                 ( 
                 30 
                 ) 
               
             
           
         
       
     
   
   Operation values CDVM_CV, CDVM_CH, CDVM_FV, and CDVM_FH are obtained according to the average values C_V 0 ˜C_V 2 , C_H 0 ˜C_H 2 , F_V 0 ˜F_V 2 , and F_H 0 ˜F_H 2 . Operation values CDVM_CV, CDVM_CH, CDVM_FV, and CDVM_FH can be recovered as (31)˜(34). 
   
     
       
         
           
             
               
                 CDVM_CV 
                 = 
                 
                   
                     
                        
                       
                         
                           C_V 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           1 
                         
                         - 
                         
                           C_V 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           0 
                         
                       
                        
                     
                     + 
                     
                        
                       
                         
                           C_V 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           1 
                         
                         - 
                         
                           C_V 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           2 
                         
                       
                        
                     
                   
                   2 
                 
               
             
             
               
                 ( 
                 31 
                 ) 
               
             
           
           
             
               
                 CDVM_CH 
                 = 
                 
                   
                     
                        
                       
                         C_H1 
                         - 
                         C_H0 
                       
                        
                     
                     + 
                     
                        
                       
                         
                           C_H 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           1 
                         
                         - 
                         
                           C_H 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           2 
                         
                       
                        
                     
                   
                   2 
                 
               
             
             
               
                 ( 
                 32 
                 ) 
               
             
           
           
             
               
                 CDVM_FV 
                 = 
                 
                   
                     
                        
                       
                         
                           F_V 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           1 
                         
                         - 
                         
                           F_V 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           0 
                         
                       
                        
                     
                     + 
                     
                        
                       
                         
                           F_V 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           1 
                         
                         - 
                         
                           F_V 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           2 
                         
                       
                        
                     
                   
                   2 
                 
               
             
             
               
                 ( 
                 33 
                 ) 
               
             
           
           
             
               
                 CDVM_FH 
                 = 
                 
                   
                     
                        
                       
                         
                           F_H 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           1 
                         
                         - 
                         
                           F_H 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           0 
                         
                       
                        
                     
                     + 
                     
                        
                       
                         
                           F_H 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           1 
                         
                         - 
                         F_H2 
                       
                        
                     
                   
                   2 
                 
               
             
             
               
                 ( 
                 34 
                 ) 
               
             
           
         
       
     
   
   A minimum value among the operation values CDVM_CV, CDVM_CH, CDVM_FV, and CDVM_FH is determined (step  215 ) and serves as a minimum operation value. The matrix corresponding to the minimum operation value serves as a minimum color difference variation matrix (MCDVM). For example, assuming that operation value CDVM_CV is the minimum. Operation value CDVM_CV is served as the minimum operation value and matrix  41  is served as the MCDVM. 
   The column color difference components or the row color difference components of the MCDVM are calculated according to the minimum operation value for obtaining a minimum color difference variation (step  216 ). In this embodiment, since the operation value CDVM_CV obtained according to the column color difference components of matrix  41  is the minimum operation value, the first, second, and third columns color difference components of matrix  41  are calculated for obtaining color difference variation clusters CDVC 0 ˜CDVC 2 . Color difference variation clusters CDVC 0 ˜CDVC 2  can be recovered as (35)˜(37).
 
 CDVC 0=|2 ×C 10 −C 00 −C 20|  (35)
 
 CDVC 1=↑2 ×C 11 −C 01 −C 21|  (36)
 
 CDVC 2=|2 ×C 12 −C 02 −C 22|  (37)
 
   A minimum color difference variation is obtained according to color difference variation clusters CDVC 0 ˜CDVC 2 . For example, when the color difference variation cluster CDVC 0  is minimum, the color difference variation cluster CDVC 0  serves as the minimum color difference variation. 
   Finally, an average value of the column or the row color difference components of the minimum color difference variation and the first image detection component R 22  are calculated for obtaining the missing component G 22  (step  217 ). The missing component G 22  is calculated as:
 
 G 22 =R 22 −C   —   V 0  (38).
 
   The missing component G 22  is obtained when steps  210 ˜ 217  shown as  FIG. 2  are executed. When steps  214 ˜ 217  are executed again for calculating the second matrix module, the missing component B 22  is obtained. 
   The color interpolation processing method of the invention accurately calculates the missing component. The calculation of color interpolation processing method of the invention is simplified such that hardware cost is reduced. 
   While the invention has been described by way of example and in terms of the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.