Digital camera, storage medium for image signal processing, carrier wave and electronic camera

Abstract

A CCD captures a subject image having passed through a taking lens and an image processing circuit performs various types of image pre-treatment including gamma correction and white balance on image data corresponding to n lines×m rows output by the CCD. The image processing circuit also performs format processing on the data. The data are then compressed at a compression circuit. The white balance adjustment and the like are implemented in line sequence at a line processing circuit which engages in signal processing in pixel sequence in units of individual lines in the output from the CCD. The image data having undergone the pre-treatment are then subjected to format processing prior to JPEG compression, at a block processing circuit that engages in signal processing in units of individual blocks each ranging over an n×m (N>n, M>m) block. In other words, the signal processing is performed in block sequence.

1 . A digital camera comprising: 
 an image-capturing device that captures a subject image having passed through a taking lens and outputs image data;    a white balance adjustment circuit that performs white balance adjustment on the image data output by said image-capturing device;    a white balance fine adjustment coefficient calculation circuit that calculates white balance fine adjustment coefficients based upon image data having undergone white balance adjustment output by said white balance adjustment circuit; and    a white balance fine adjustment circuit that performs white balance fine adjustment on the image data having undergone the white balance adjustment output by said white balance adjustment circuit using said white balance fine adjustment coefficients.    
   
   
       2 . A digital camera according to  claim 1 , wherein: 
 said white balance fine adjustment coefficient calculation circuit calculates average values of R, B and G signals in the image data having undergone white balance adjustment and calculates white balance fine adjustment coefficients based upon average values.    
   
   
       3 . A digital camera according to  claim 1 , wherein: 
 said white balance fine adjustment coefficient calculation circuit calculates histograms of brightness levels of R, B and G signals in the image data having undergone white balance adjustment and calculates white balance fine adjustment coefficients based upon the histograms.    
   
   
       4 . A storage medium for image processing having a program stored therein that executes: 
 white balance adjustment processing in which white balance adjustment is performed on image data of an image captured at an image-capturing device;    white balance fine adjustment coefficient calculation processing in which white balance fine adjustment coefficients are calculated using image data having undergone white balance adjustment through said white balance adjustment processing; and    white balance fine adjustment processing in which white balance fine adjustment is performed on image data having undergone white balance adjustment using said white balance fine adjustment coefficients.    
   
   
       5 . A storage medium for image processing according to  claim 4 , wherein: 
 in said white balance fine adjustment coefficient calculation processing, average values of R and B signals in the image data having undergone white balance adjustment are calculated and white balance fine adjustment coefficients are calculated based upon the average values.    
   
   
       6 . A storage medium for image processing according to  claim 4 , wherein: 
 in said white balance fine adjustment coefficient calculation processing, histograms of brightness levels of R, B and G signals in the image data having undergone white balance adjustment are calculated and white balance fine adjustment coefficients are calculated based upon the histograms.    
   
   
       7 . A digital camera comprising: 
 an image-capturing device that captures a subject image having passed through a taking lens and outputs image data;    a white balance adjustment circuit that performs white balance adjustment on the image data output by said image-capturing device;    an image area selection apparatus that selects one image area from a preset plurality of image areas;    a white balance fine adjustment coefficient calculation circuit that calculates white balance fine adjustment coefficients based upon image data within an area set in relation to an image area selected by said image area selection apparatus, in image data having undergone white balance adjustment output by said white balance adjustment circuit; and    a white balance fine adjustment circuit that performs white balance fine adjustment using said white balance fine adjustment coefficients calculated at said white balance fine adjustment coefficient calculation circuit.    
   
   
       8 . A digital camera according to  claim 7 , further comprising: 
 a focal point detection device that detects focal adjustment statuses relative to various subjects in a preset plurality of focal white detection areas; and    a focal point detection area selection apparatus that selects one of said plurality of focal point detection areas based upon the focal adjustment statuses, wherein:    said image area selection apparatus selects image data in an image area set in relation to the focal point detection area selected by said focal point detection area selection apparatus.    
   
   
       9 . A digital camera according to  claim 7 , wherein: 
 said white balance fine adjustment coefficient calculation circuit calculates average values of R, G and B signals in data in an image area selected by said image area selection apparatus after the white balance adjustment and calculates white balance fine adjustment coefficients based upon the average values.    
   
   
       10 . A digital camera according to  claim 7 , wherein: 
 said white balance fine adjustment coefficient calculation circuit calculates histograms of brightness levels of R, G and B signals in data in an image area selected by said image area selection apparatus after the white balance adjustment and calculates white balance fine adjustment coefficients based upon the histograms.    
   
   
       11 . A storage medium for image processing having a program stored therein that executes: 
 white balance adjustment processing in which white balance adjustment is performed on image data of an image captured at an image-capturing device;    image area selection processing in which an image area is selected from a preset plurality of image areas;    white balance fine adjustment coefficient calculation processing in which white balance fine adjustment coefficients are calculated using image data within an area set in relation to the image area selected through said image area selection processing; and    white balance fine adjustment processing in which white balance fine adjustment is performed on image data having undergone white balance adjustment using white balance fine adjustment coefficients.    
   
   
       12 . A storage medium for image processing according to  claim 11 , wherein: 
 in said image area selection processing, information related to a focal point detection area from which a focal adjustment status used for a focus matching operation at a taking lens has been detected among a preset plurality of focal point detection areas is used as a basis for selecting an image area related to said focal point detection area.    
   
   
       13 . A storage medium for image processing according to  claim 11 , wherein: 
 in said white balance fine adjustment coefficient calculation processing, average values of R, G and B signals in image data in an image area selected through said image area selection processing after the white balance adjustment are calculated and white balance fine adjustment coefficients are calculated based upon the average values.    
   
   
       14 . A storage medium for image processing according to  claim 11 , wherein: 
 in said white balance fine adjustment coefficient calculation processing, histograms of brightness levels of R, G and B signals in image data in an image area selected through said image area selection processing after the white balance adjustment are calculated and white balance fine adjustment coefficients are calculated based upon the histograms.    
   
   
       15 . A carrier wave encoded to transmit a control program for white balance adjustment on image data, the control program including instructions for: 
 white balance adjustment processing in which white balance adjustment is performed on image data of an image captured at an image-capturing device;    image area selection processing in which an image area is selected from a preset plurality of image areas;    white balance fine adjustment coefficient calculation processing in which white balance fine adjustment coefficients are calculated using image data within an area set in relation to the image area selected through said image area selection processing; and    white balance fine adjustment processing in which white balance fine adjustment is performed on image data having undergone white balance adjustment using white balance fine adjustment coefficients.    
   
   
       16 . A carrier wave according to  claim 15 , wherein: 
 in said image area selection processing, information related to a focal point detection area from which a focal adjustment status used for a focus matching operation at a taking lens has been detected among a preset plurality of focal point detection areas is used as a basis for selecting an image area related to said focal point detection area.    
   
   
       17 . A carrier wave according to  claim 15 , wherein: 
 in said white balance fine adjustment coefficient calculation processing, average values of R, G and B signals in image data in an image area selected through said image area selection processing after the white balance adjustment are calculated and white balance fine adjustment coefficients are calculated based upon the average values.    
   
   
       18 . A carrier wave according to  claim 15 , wherein: 
 in said white balance fine adjustment coefficient calculation processing, histograms of brightness levels of R, G and B signals in image data in an image area selected through said image area selection processing after the white balance adjustment are calculated and white balance fine adjustment coefficients are calculated based upon the histograms.