Method of fast image matching

• US 9,165,215 B2
• Filed: 04/24/2013
• Issued: 10/20/2015
• Est. Priority Date: 01/25/2013
• Status: Active Grant

• Current Assignee: Delta Electronics Incorporated
• Original Assignee: Delta Electronics Incorporated
• Inventors: Wei, Juang-Yu
• Primary Examiner(s): Park, Chan
• Assistant Examiner(s): Thomas, Mia M
• Application Number:
  US13/869,471
• Publication Number:
  US 20140212052A1
• Time in Patent Office: 909 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G06V 10/754 involving a deformation of the sample pattern or of the reference pattern; Elastic matching

Abstract

Disclosed herein is a method of fast image matching that includes the steps as follows. A template image with a predetermined angular orientation is compared with template images in the range from 0 to 360 degrees to create an angle prediction table. Next, a testing image is acquired and compared with the template image with the predetermined angular orientation to record the similarity at each position, and a plurality of angles corresponding to the similarity is found from the angle prediction table. Afterwards, the template images of the plurality of angles are respectively compared with the testing image to obtain the highest similarity as a comparison result of the position.

Claims

1. A method of fast image matching, comprising:

(a) using a computer for pre-comparing a template image having a predetermined angular orientation with the template images rotated in a range from 0 to 360 degrees respectively, so as to create an angle prediction table;

(b) using the computer for acquiring a testing image, comparing the testing image to the template image having the predetermined angular orientation so as to record at least one similarity between each portion of the testing image and the template image, wherein a size of the each portion of the testing image is equal to a size of the template image, and finding a plurality of angles from the angle prediction table, wherein the plurality of angles in the angle prediction table have respective scores that are greater than the at least one similarity; and

(c) using the computer for comparing each of the template images associated with the plurality of angles respectively to the testing image so as to obtain a highest similarity.

2. The method of fast image matching of claim 1, wherein the step (a) comprises:

comparing the template image with a predetermined angular orientation of 0 degree with the template images in the range from 0 to 360 degrees to record the comparison results;

determining if the comparison has been completed for each degree from 0 to 360; and

after the comparison has been completed, creating the angle prediction table according to the comparison results.

3. The method of fast image matching of claim 1, wherein the at least one similarity of each portion of the testing image at each position is a numerical value, and in the angle prediction table the scores of the template images with the plurality of angles is greater than the numerical value;

in addition, the step (c) comprises;

acquiring the template images with the plurality of angles, comparing the template images with the plurality of angles with the testing image at the each position, and outputting the highest similarity after an entire piece of the testing image is compared.

4. A method of fast image matching, comprising:

(a) using a computer for comparing a template image having a predetermined angular orientation with the template images rotated in a range from 0 to 360 degrees respectively, so as to create an angle prediction table;

(b) using the computer for acquiring a testing image, and utilizing a circular projection method to find an area of an object corresponding to the template image in the testing image;

(c) using the computer for comparing the area in the testing image to the template image having the predetermined angular orientation so as to record at least one similarity between each portion of the testing image and the template image, wherein a size of the each portion of the testing image is equal to a size of the template image, and finding a plurality of angles from the angle prediction table, wherein the plurality of angles in the angle prediction table have respective scores that are greater than the at least one similarity; and

(d) using the computer for comparing each of the template images associated with the plurality of angles respectively to the testing image so as to obtain a highest similarity.

5. The method of fast image matching of claim 4, wherein the step (a) comprises:

comparing the template image with a predetermined angular orientation of 0 degree with the template images in the range from 0 to 360 degrees to record the comparison results;

determining if the comparison has been completed for each degree from 0 to 360; and

after the comparison has been completed, creating the angle prediction table according to the comparison results.

6. The method of fast image matching of claim 4, wherein the at least one similarity of each portion of the testing image at each position is a numerical value, and the scores of the template images with the plurality of angles in the angle prediction table is greater than the value;

in addition, the step (d) comprises;

acquiring the template images with the plurality of angles, comparing the template images with the plurality of angles with the testing image a the each position, and outputting the highest similarity after the area within the testing image is compared.