Image processing system
First Claim
1. An image processing apparatus comprising:
- first processor means for extracting a desired partial image area from each of a pair of first and second images to be subjected to position alignment;
second processor means for dividing each of said partial image areas into n x m image segments arranged in a matrix form, where n and m are positive integers;
third processor means for detecting, in a first mode, misalignment between each corresponding image segment pair of said first and second picture images by using a first evaluation parameter defined based upon correlation coefficient data, and for more accurately detecting, in a second mode, the misalignment between the same image segment pair of said first and second picture images by using a second evaluation parameter which is defined based upon pixel density difference data as well as the correlation coefficient data; and
fourth processor means for aligning said first and second picture images based on misalignment data obtained for all of said image segment pairs by said third processor means.
1 Assignment
0 Petitions
Accused Products
Abstract
According to the image self-alignment system of the present invention, desired partial image areas are extracted by a partial image area designator from a pair of to-be-aligned picture images used for, for example, medical purposes. Each partial image area is divided by an area divider into a plurality of image segments arranged in a matrix form. Each corresponding image segment pair is subjected to a first misalignment detection by using a first evaluation parameter called correlation coefficient data. Each image segment pair is then subjected to a second misalignment detection by using a second evaluation parameter including pixel density difference data for finer detection. The first and second picture images are automatically aligned based on highly reliable final misalignment data obtained by carrying out the first and second misalignment detections.
-
Citations
11 Claims
-
1. An image processing apparatus comprising:
-
first processor means for extracting a desired partial image area from each of a pair of first and second images to be subjected to position alignment; second processor means for dividing each of said partial image areas into n x m image segments arranged in a matrix form, where n and m are positive integers; third processor means for detecting, in a first mode, misalignment between each corresponding image segment pair of said first and second picture images by using a first evaluation parameter defined based upon correlation coefficient data, and for more accurately detecting, in a second mode, the misalignment between the same image segment pair of said first and second picture images by using a second evaluation parameter which is defined based upon pixel density difference data as well as the correlation coefficient data; and fourth processor means for aligning said first and second picture images based on misalignment data obtained for all of said image segment pairs by said third processor means. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. An image processing method comprising the steps of:
-
extracting a desired partial image area from a pair of first and second picture images to be aligned; dividing each of said partial image areas into n x m image segments arranged in a matrix form, where n and m are positive integers; sequentially calculating first evaluation function defined based on correlation data between a selected one of corresponding n x m image segment pairs while shifting one of the selected image segment pair on an image plane, thereby performing a first misalignment detection between said image segment pair; terminating said first misalignment detection when a variation in said first evaluation function falls below a predetermined first threshold level, detecting a maximum of said first evaluation function and calculating a misalignment between the image segment pair at the time said maximum first evaluation function is detected; sequentially calculating a second evaluation function including said correlation data and pixel density difference data between the selected image segment pair to thereby perform a second misalignment detection; and calculating, when a maximum of the calculated second evaluation function exceeds a predetermined second threshold level, a misalignment quantity between the selected image segment pair at the time said maximum second evaluation function is detected and terminating said second misalignment detection, whereby final misalignment vector data for the selected image segment pair is obtained. - View Dependent Claims (9, 10, 11)
-
Specification