IMAGE RECORDING METHOD, IMAGE RECORDING DEVICE, AND STORAGE MEDIUM

• US 20090237529A1
• Filed: 03/18/2009
• Published: 09/24/2009
• Est. Priority Date: 03/19/2008
• Status: Active Grant

• Current Assignee: Casio Computer Company Limited
• Original Assignee: Casio Computer Company Limited
• Inventors: NAKAGOMI, Kouichi, Onodera, Yutaka, Matsui, Shinichi
• Granted Patent: US 8,013,913 B2
• Time in Patent Office: Days
• US Class Current: 348/231.990
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/30196 Human being; Person
• CPC Class Codes: G06T 7/277 involving stochastic approaches, e.g. using Kalman filters
• CPC Class Codes: H04N 23/635 Region indicators; Field of view indicators
• CPC Class Codes: H04N 23/673 based on contrast or high frequency components of image signals, e.g. hill climbing method
• CPC Class Codes: H04N 23/675 comprising setting of focusing regions
• CPC Class Codes: H04N 5/144 Movement detection for video coding H04N19/503; analysis of motion in general G06T7/20
• CPC Class Codes: H04N 5/147 Scene change detection

Abstract

An image recording comprising: an initialization step of generating a predetermined number of search points in a specified region of an image, a filtering step of updating coordinates of a plurality of search points, comparing a characteristic value of the specified region with a characteristic value of each of the search points after updated in the image, assigning to the search points weights determined so as to he increased in proportion to a degree of similarity therebetween, screening the search points according to the weights, calculating a variance and a weighted average of the coordinates of the screened search points, and an image recording determination step of determining, based on the variance and weighted average of the coordinates of the screened search points, and the tracking range, whether or not to record the image, and recording the image if it is determined to record the image.

Claims

1. An image recording method for sequentially obtaining consecutive images, and recording one image from among the images, comprising:

an initialization step comprising;

a step of setting a specified region and a tracking range surrounding the specified region within the image,

a step of storing a characteristic value of the specified region within the image, and

a step of generating a predetermined number of search points in the specified region of the image,

a filtering step comprising;

a step of updating coordinates of a plurality of search points by using a random number,

a step of comparing the characteristic value of the specified region with a characteristic value of each of the search points after being updated in the image, assigning to the search points weights determined so as to be increased in proportion to a degree of similarity therebetween,

a step of screening the search points according to the weights thus assigned thereto,

a step of calculating a variance of the coordinates of the screened search points, and

a step of calculating a weighted average of the coordinates of the screened search points, and

an image recording determination step of determining, based on the variance of the coordinates of the screened search points, the weighted average of the coordinates of the screened search points, and the tracking range, whether or not to record the image, and recording the image in a case of determining to record the image.

2. An image recording method according to claim 1, wherein the step of screening the search points according to the weights includes calculating a summation of the weights of the search points, generating only a number of identifiers equal to this summation, associating the identifiers with the search points respectively according to the weights, selecting identifiers only the predetermined number of times randomly from among the identifiers, and storing the search points corresponding to the selected identifiers.

3. An image recording method according to claim 1, wherein the step of screening the search points according to the weights includes eliminating search points each for which the weight is less than or equal to a predetermined threshold.

4. An image recording method according to claim 1, further comprising a learning step of executing the initialization step and the filtering step on a first image, and subsequently, repeating the filtering step for each of the images from the 2nd to the kth (k being a natural number), and

an image recording step of, for images of the (k+1)st or later, repeating the filtering step and the image recording determination step.

5. An image recording method according to claim 4, wherein, after executing the learning step, until executing the image recording step, the the specified region and the tracking range are tracked and moved by repeating the filtering step.

6. An image recording method according to claim 4, wherein, in the step of calculating a weighted average of the coordinates of the screened search points in the learning step, in a case in which the weighted average of the coordinates of the screened search points are positioned exterior to the tracking range, an error is output.

7. An image recording method according to claim 4, wherein, in the step of calculating a variance of the coordinates of the screened search points in the learning step, in a case in which the variance is greater than or equal to a predetermined threshold, an error is output.

8. An image recording method according to claim 4, wherein, in the step of calculating a variance of the coordinates of the screened search points in the learning step, in a case in which the amount of variation of the variance from a previous variance is large, an error is output.

9. An image recording method according to claim 4, wherein, in the step of calculating a weighted average of the coordinates of the screened search points in the image recording step, in a case in which the weighted average of the coordinates of the screened search points is positioned exterior to the tracking range, the image is recorded.

10. An image recording method according to claim 4, wherein, in the step of calculating a variance of the coordinates of the screened search points in the image recording step, in a case in which the variance is greater than or equal to a predetermined threshold, the image is recorded.

11. An image recording method according to claim 4, wherein, in the step of calculating a variance of the coordinates of the screened search points in the image recording step, in a case in which the amount of a variation of the variance from a previous variance is large, the image is recorded.

12. A storage medium storing therein a program executable by a computer to carry out the image recording method according to claim 1.

14. A storage medium storing therein a program executable by a computer to carry out the image recording method according to claim 2.

15. A storage medium storing therein a program executable by a computer to carry out the image recording method according to claim 3.

16. A storage medium storing therein a program executable by a computer to carry out the image recording method according to claim 4.

17. A storage medium storing therein a program executable by a computer to carry out the image recording method according to claim 5.

18. A storage medium storing therein a program executable by a computer to carry out the image recording method according to claim 6.

19. A storage medium storing therein a program executable by a computer to carry out the image recording method according to claim 7.

20. A storage medium storing therein a program executable by a computer to carry out the image recording method according to claim 8.

13. An image recording device for sequentially obtaining consecutive images, and recording one image from among the images, comprising:

an initialization means for setting a specified region and a tracking range surrounding the specified region within the image, storing a characteristic value of the specified region within the image, and generating a predetermined number of search points in the specified region of the image,

a filtering means for updating coordinates of a plurality of search points by using a random number, comparing the characteristic value of the specified region with a characteristic value of each of the search points after being updated in the image, assigning to the search points weights determined so as to be increased in proportion to a degree of similarity therebetween, screening the search points according to the weights thus assigned thereto, calculating a variance of the coordinates of the screened search points, and calculating a weighted average of the coordinates of the screened search points, and

an image recording determination means for, based on the variance of the coordinates of the screened search points, the weighted average of the coordinates of the screened search points, and the tracking range, determining whether or not to record the image, and recording the image in a case of determining to record the image.