Digital image processing using face detection and skin tone information

Abstract

A technique for processing a digital image uses face detection to achieve one or more desired image processing parameters. A group of pixels is identified that corresponds to a face image within the digital image. A skin tone is detected for the face image by determining one or more default color or tonal values, or combinations thereof, for the group of pixels. Values of one or more parameters are adjusted for the group of pixels that correspond to the face image based on the detected skin tone.

What is claimed is: 
     
         1 . A method of processing a digital image using face detection to achieve one or more desired image processing parameters, comprising:
 identifying a group of pixels that correspond to a face image within the digital image;   detecting a skin tone for the face image by determining one or more default color or tonal values, or combinations thereof, for the group of pixels; and   adjusting values of one or more parameters for the group of pixels that correspond to the face image based on the detected skin tone.   
     
     
         2 . The method of  claim 1 , wherein the adjusting comprises applying fill-flash to the face image in an amount depending on the skin tone. 
     
     
         3 . The method of  claim 1 , further comprising repeating the identifying, detecting and adjusting for a second face image having a different skin tone than the first face image, and the adjusting comprises applying fill-flash to the two face images in different relative amounts depending on the different skin tones. 
     
     
         4 . The method of  claim 1 , wherein the adjusting comprises adjusting a luminance of the face image depending on the skin tone. 
     
     
         5 . The method of  claim 1 , further comprising repeating the identifying, detecting and adjusting for a second face image having a different skin tone than the first face image, and the adjusting comprises adjusting luminance values of pixels of the two face images in different relative amounts depending on the different skin tones. 
     
     
         6 . The method of  claim 1 , wherein the color or tonal values for the group of pixels comprise one or more average color or tonal values. 
     
     
         7 . The method of  claim 6 , wherein the color or tonal values comprise multiple colors or tones, or combinations thereof, determined for each of multiple regions of the face image. 
     
     
         8 . An image acquisition apparatus including an imaging optical system and digital image detector and storage medium, and having stored therein program instructions for programming one or more processors to perform a method of processing a digital image using face detection to achieve one or more desired image processing parameters, the method comprising:
 identifying a group of pixels that correspond to a face image within the digital image;   detecting a skin tone for the face image by determining one or more default color or tonal values, or combinations thereof, for the group of pixels; and   adjusting values of one or more parameters for the group of pixels that correspond to the face image based on the detected skin tone.   
     
     
         9 . The apparatus of  claim 8 , wherein the adjusting comprises applying fill-flash to the face image in an amount depending on the skin tone. 
     
     
         10 . The apparatus of  claim 8 , wherein the method further comprises repeating the identifying, detecting and adjusting for a second face image having a different skin tone than the first face image, and the adjusting comprises applying fill-flash to the two face images in different relative amounts depending on the different skin tones. 
     
     
         11 . The apparatus of  claim 8 , wherein the adjusting comprises adjusting a luminance of the face image depending on the skin tone. 
     
     
         12 . The apparatus of  claim 8 , wherein the method further comprises repeating the identifying, detecting and adjusting for a second face image having a different skin tone than the first face image, and the adjusting comprises adjusting luminance values of pixels of the two face images in different relative amounts depending on the different skin tones. 
     
     
         13 . The apparatus of  claim 8 , wherein the color or tonal values for the group of pixels comprise one or more average color or tonal values. 
     
     
         14 . The apparatus of  claim 13 , wherein the color or tonal values comprise multiple colors or tones, or combinations thereof, determined for each of multiple regions of the face image. 
     
     
         15 . One or more digital storage devices having embodied therein program instructions for programming one or more processors to perform a method of processing a digital image using face detection to achieve one or more desired image processing parameters, the method comprising:
 identifying a group of pixels that correspond to a face image within the digital image;   detecting a skin tone for the face image by determining one or more default color or tonal values, or combinations thereof, for the group of pixels; and   adjusting values of one or more parameters for the group of pixels that correspond to the face image based on the detected skin tone.   
     
     
         16 . The one or more storage devices of  claim 15 , wherein the adjusting comprises applying fill-flash to the face image in an amount depending on the skin tone. 
     
     
         17 . The one or more storage devices of  claim 15 , wherein the method further comprises repeating the identifying, detecting and adjusting for a second face image having a different skin tone than the first face image, and the adjusting comprises applying fill-flash to the two face images in different relative amounts depending on the different skin tones. 
     
     
         18 . The one or more storage devices of  claim 15 , wherein the adjusting comprises adjusting a luminance of the face image depending on the skin tone. 
     
     
         19 . The one or more storage devices of  claim 15 , wherein the method further comprises repeating the identifying, detecting and adjusting for a second face image having a different skin tone than the first face image, and the adjusting comprises adjusting luminance values of pixels of the two face images in different relative amounts depending on the different skin tones. 
     
     
         20 . The one or more storage devices of  claim 15 , wherein the color or tonal values for the group of pixels comprise one or more average color or tonal values.