Image processing method and apparatus for face image
AssigneeFUJIFILM Corporation
InventorYusuke OMORI
Life of this patent
Estimating the term…
Abstract
An image processing method for a face image is provided. A skin area of a face is segmented from the face image. A brightness histogram of the skin area is generated. A skin shadow point and an eyeball point of the face are extracted from the skin area, the shadow point having a lowest brightness in the skin area. A modified histogram is generated by modifying the brightness histogram so as to correct a specific area having a lower brightness level than the eyeball point at a brightness level of the eyeball point, and to correct a specific portion in the skin area having a higher brightness level than the shadow point at a brightness level of the shadow point. The face image is thresholded in consideration of the modified histogram to produce a binary image or N-level encoded image.
Claims9
An image processing method of image processing of a face image, comprising steps of:
- processing said face image monochromatically by gray scale processing;
- segmenting a first image area inclusive of a skin area of a face from said face image after said gray scale processing;
- specifying a second image area inclusive of said first image area and also a hair area of said face in said face image;
- generating a brightness histogram of said first image area;
- extracting a shadow point and an eyeball point of said face from said first image area, said shadow point having a lowest brightness in said skin area;
- generating a modified histogram by modifying said brightness histogram so as to correct a specific area having a lower brightness level than said eyeball point at a brightness level of said eyeball point, and to correct a specific portion in said skin area having a higher brightness level than said shadow point at a brightness level of said shadow point;
- determining one to three thresholds from said modified histogram;
- thresholding said second image area by use of said one to three thresholds to produce an N-level encoded image, where N is an integer of 2 or more.
An image processing apparatus for image processing of a face image, comprising:
- a gray scale processing device for processing said face image monochromatically by gray scale processing;
- an image segmentation device for segmenting a first image area inclusive of a skin area of a face from said face image after said gray scale processing;
- an area specifying device for specifying a second image area inclusive of said first image area and also a hair area of said face in said face image;
- a histogram generator for generating a brightness histogram of said first image area;
- a feature point extracting device for extracting a shadow point and an eyeball point of said face from said first image area, said shadow point having a lowest brightness in said skin area;
- a modified histogram generator for generating a modified histogram by modifying said brightness histogram so as to correct a specific area having a lower brightness level than said eyeball point at a brightness level of said eyeball point, and to correct a specific portion in said skin area having a higher brightness level than said shadow point at a brightness level of said shadow point;
- a threshold generator for determining one to three thresholds from said modified histogram;
- an image thresholding device for thresholding said second image area by use of said one to three thresholds to produce an N-level encoded image, where N is an integer of 2 or more.
Dependencies are inferred from the claim text.