Output image adjustment of image data

Abstract

A CPU calculates modified brightness correction amount tCurve_Y with consideration of exposure correction amount (or exposure value) EV if photography information PI (or Exif IFD) is included in image data GF. Specifically, the modified brightness correction amount tCurve_Y is calculated by dividing original brightness correction amount tCurve_Yorg by 2 |EV| . Therefore, it decreases in geometrical progression as the exposure correction amount increases. The CPU applies the obtained modified brightness correction amount tCurve_Y to a tone curve to adjust image quality including brightness. More specifically, it uses the modified brightness correction amount tCurve_Y to modify the characteristics of the tone curve, and then uses the modified tone curve to adjust the image quality of the image data.

1 . An image processing apparatus for using image data and exposure correction amount for the image data to perform image processing on the image data, the image processing apparatus comprising:
 a correction amount determination module for determining brightness correction amount of the image data based on a brightness reference value that is used as a reference of image processing relating to brightness;   a correction amount modification module for decreasing the brightness correction amount as the exposure correction amount increases; and   an image quality adjustment module for applying the modified brightness correction amount to adjust brightness of the image data.   
     
     
         2 . An image processing apparatus according to  claim 1 , wherein the correction amount modification module applies different degrees of change in the brightness correction amount to the exposure correction amount smaller than a predetermined exposure correction amount and the exposure correction amount larger than or equal to the predetermined exposure correction amount. 
     
     
         3 . An image processing apparatus according to  claim 1 , wherein the correction amount modification module decreases the decreasing rate of the brightness correction amount as the exposure correction amount increases. 
     
     
         4 . An image processing apparatus according to  claim 2 , wherein the correction amount modification module decreases the brightness correction amount in geometrical progression as the exposure correction amount increases. 
     
     
         5 . An image processing apparatus according to  claim 4 , wherein the correction amount modification module divides the brightness correction amount by an exponential function that has the exposure correction amount as a parameter. 
     
     
         6 . An image processing apparatus according to  claim 5 , further comprising:
 a brightness characteristic value acquisition module for analyzing the image data to acquire a brightness characteristic value indicating characteristics of brightness of the image data,   wherein the correction amount determination module determines the brightness correction amount so as to reduce a difference between the brightness reference value and the acquired brightness characteristic value.   
     
     
         7 . An image processing apparatus according to  claim 5 , further comprising:
 an input module for inputting a tendency of brightness correction for the image data,   wherein the correction amount determination module determines brightness correction amount of the image data based on the input tendency of brightness correction.   
     
     
         8 . An image processing apparatus according to  claim 6 , further comprising:
 an image output module for using the brightness-adjusted image data to output an image.   
     
     
         9 . An image processing apparatus according to  claim 1  wherein the correction amount modification module modifies the brightness correction amount in consideration of a luminance difference between before and after contrast correction, and
 the image data and the exposure correction amount are stored in a same file.   
     
     
         10 . An image processing apparatus for using image data and information on exposure correction performed on the image data to perform image processing on the image data, the image processing apparatus comprising:
 a brightness characteristic value acquisition module for analyzing the image data to acquire a brightness characteristic value indicating characteristics of brightness of the image data;   an image quality adjustment module for reducing a difference between a brightness reference value that is used as a reference of image processing relating to brightness and the acquired brightness characteristic value; and   a reduced difference amount adjustment module for decreasing a degree of reduction in the difference based on the information on exposure correction increases as a degree of exposure correction performed on the image data.   
     
     
         11 . An image processing apparatus according to  claim 10 , wherein the correction amount modification module applies different degrees of change in the brightness correction amount to the exposure correction amount smaller than a predetermined exposure correction amount and the exposure correction amount larger than or equal to the predetermined exposure correction amount. 
     
     
         12 . An image processing apparatus according to  claim 10 , wherein the correction amount modification module decreases the decreasing rate of the brightness correction amount as the exposure correction amount increases. 
     
     
         13 . An image processing apparatus according to  claim 12 , wherein a degree of reduction in the difference is decreased by the reduced difference amount adjustment module in geometrical progression. 
     
     
         14 . An image processing apparatus according to  claim 10 , wherein the image data and the information on exposure correction are stored in a same file. 
     
     
         15 . An image processing method for using image data and exposure correction amount for the image data to perform image processing on the image data, the method comprising:
 determining brightness correction amount of the image data based on a brightness reference value that is used as a reference of image processing relating to brightness;   modifying the brightness correction amount smaller as the exposure correction amount increases; and   applying the modified brightness correction amount to adjust brightness of the image data.   
     
     
         16 . An image processing method according to  claim 15 , wherein in the modifying the brightness correction amount, different degrees of change in the brightness correction amount are applied to the exposure correction amount smaller than a predetermined exposure correction amount and the exposure correction amount larger than or equal to the predetermined exposure correction amount. 
     
     
         17 . An image processing method according to  claim 15 , wherein the decreasing rate of the brightness correction amount is decreased as the exposure correction amount increases. 
     
     
         18 . An image processing method according to  claim 17 , wherein the brightness correction amount is modified smaller in geometrical progression. 
     
     
         19 . An image processing method according to  claim 15 , further comprising:
 analyzing the image data to a brightness characteristic value indicating characteristics of brightness of the image data;   determining the brightness correction amount so as to reduce a difference between the brightness reference value and the acquired brightness characteristic value; and   dividing the determined brightness correction amount by an exponential function that has the exposure correction amount as a parameter.   
     
     
         20 . An image processing method according to  claim 15 , further comprising:
 receiving a tendency of brightness correction for the image data;   determining brightness correction amount of the image data based on the received tendency of brightness correction; and   dividing the determined brightness correction amount by an exponential function that has the exposure correction amount as a parameter.   
     
     
         21 . A computer readable medium storing an image processing program for using image data and exposure correction amount for the image data to perform image processing on the image data, the image processing program causing a computer to implement the functions of:
 determining brightness correction amount of the image data based on a brightness reference value that is used as a reference of image processing relating to brightness;   modifying the brightness correction amount smaller as the exposure correction amount increases; and   applying the modified brightness correction amount to adjust brightness of the image data.   
     
     
         22 . A computer readable medium according to  claim 21 , wherein the function of modifying the brightness correction amount applies different degrees of change in the brightness correction amount to the exposure correction amount smaller than a predetermined exposure correction amount and the exposure correction amount larger than or equal to the predetermined exposure correction amount. 
     
     
         23 . A computer readable medium according to  claim 21 , wherein the decreasing rate of the brightness correction amount is decreased as the exposure correction amount increases. 
     
     
         24 . A computer readable medium according to  claim 23 , wherein the brightness correction amount is decreased in geometrical progression. 
     
     
         25 . A computer readable medium according to  claim 21 , the image processing program further causing the computer to implement the function of:
 analyzing the image data to acquire a brightness characteristic value indicating characteristics of brightness of the image data,   wherein the function of determining the correction amount determines the brightness correction amount so as to reduce a difference between the brightness reference value and the acquired brightness characteristic value, and   the function of modifying the brightness correction amount divides the determined brightness correction amount by an exponential function that has the exposure correction amount as a parameter.   
     
     
         26 . A computer readable medium according to  claim 21 , the image processing program further causing the computer to implement the function of:
 inputting a tendency of brightness correction for the image data,   wherein the function of determining the correction amount determines brightness correction amount of the image data based on the input tendency of brightness correction, and   the function of modifying the brightness correction amount divides the determined brightness correction amount by an exponential function that has the exposure correction amount as a parameter.   
     
     
         27 . A computer readable medium according to  claim 21 , the image processing program further causing the computer to implement the function of:
 outputting the brightness-adjusted image data to an output device.   
     
     
         28 . An image processing apparatus for performing image processing on image data associated with photography information indicating photography conditions at the time of shooting, the image processing apparatus comprising:
 an image quality characteristic value acquisition module for analyzing acquired image data to acquire an image quality characteristic value indicating characteristics of image quality of the image data;   a search module for searching the photography information associated with the acquired image data for photography information indicating an intention of photography;   an image quality adjustment module for reducing a difference between a predetermined image quality adjustment reference value that is used as a reference of image quality adjustment and the acquired image quality characteristic value to adjust image quality of the image data; and   a reduced difference amount adjustment module for using the searched photography information indicating an intention of photography to adjust a degree of reduction in the difference if the photography information indicating an intention of photography is detected.   
     
     
         29 . An image processing apparatus according to  claim 28 , wherein if the photography information indicating an intention of photography is not detected, a degree of reduction in the difference is not adjusted by use of the photography information indicating an intention of photography.