Image processor, image processing apparatus, and image processing method

• US 20010031086A1
• Filed: 03/12/2001
• Published: 10/18/2001
• Est. Priority Date: 12/25/1996
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Hotta, Takashi
• Granted Patent: US 6,898,318 B2
• Time in Patent Office: Days
• US Class Current: 382/209
• CPC Class Codes: G06T 7/20 Analysis of motion motion estimation for coding, decoding, compressing or decompressing digital video signals H04N19/43, H04N19/51
• CPC Class Codes: G06V 10/7515 Shifting the patterns to accommodate for positional errors

Abstract

An image processing apparatus obtains a sum A of image data values of pixels in a template image, a sum B of squares of image data values of pixels in a template image, a sum C of image data values of pixels in a sub-image to be processed, of a search image, a sum D of squares of image data values of pixels in the sub-image of the template image, further obtains a threshold value F in advance by using the obtained values A, B, C and D, the number P of pixels in the template image, and the preset value E. Moreover, the apparatus obtains a square of each difference between an image data value of each pixel in the sub-image and that of a corresponding pixel in the template image, and performs cumulative addition for each obtained squares. If the result of cumulative addition exceeds the above-mentioned threshold value, the apparatus closes processing evaluation of a similarity between the sub-image and the template image. Furthermore, the apparatus recursively obtains a moving-average value of image data values of pixels in a rectangular region to be presently processed, by using a moving-average value for a rectangular region which was previously processed and image data read from a first memory and a second memory, each memory stores image data by one line pixels of the image, which include image data of pertinent pixels in the rectangular regions.

Claims

1. A template matching method, comprising the steps of:

obtaining a threshold value used as a similarity evaluation measure by using image data values of pixels in a template image and image data values of pixels in a sub-image to be processed, of which the size is equal to the size of said template image, of a search image;

obtaining a square of a difference between an image data value of a pixel in said sub-image to be processed, and an image data value of a corresponding pixel in said template image;

performing cumulative addition for said obtained square; and

repeating the step of obtaining a square and the step of performing cumulative addition;

wherein if a result of said cumulative addition exceeds said threshold value, evaluation of a similarity for said sub-image is closed.