Automatically cropping an image

• US 20070076979A1
• Filed: 10/03/2005
• Published: 04/05/2007
• Est. Priority Date: 10/03/2005
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Ma, Wei-Ying, Zhang, Lei, Zhang, Mingju, Sun, Yan-Feng
• Granted Patent: US 7,529,390 B2
• Time in Patent Office: Days
• US Class Current: 382/282
• CPC Class Codes: G06T 2207/20132 Image cropping
• CPC Class Codes: G06T 2207/30201 Face
• CPC Class Codes: G06T 7/74 involving reference images or patches
• CPC Class Codes: G06V 10/32 Normalisation of the pattern dimensions
• CPC Class Codes: G06V 40/16 Human faces, e.g. facial parts, sketches or expressions
• CPC Class Codes: H04N 1/3873 defined only by a limited number of coordinate points or parameters, e.g. corners, centre; for trimming

Abstract

A method and system for cropping an image is provided. The cropping system automatically crops an image by selecting an image template whose condition is best satisfied by the image and then by selecting a cropping of the image that best attains the goal of the selected image template. The cropping system may use a metric or objective function to rate how well a cropping attains the goal of the selected image template. The cropping system may apply various optimization algorithms to identify a cropping that is the best as indicated by the metric. The cropping system can then automatically crop the image based on the identified cropping.

Claims

1. A method in a computing system for cropping an image, the method comprising:

providing image templates having conditions and goals;

providing an objective function that generates a rating of a candidate cropping of the image to meet the goal of an image template;

selecting an image template whose condition is satisfied by the image;

identifying a candidate cropping based on the rating of the objective function of the candidate cropping to the selected image template; and

cropping the image in accordance with the identified cropping.

2. The method of claim 1 wherein a condition of an image template indicates number of face areas and size of face areas.

3. The method of claim 2 wherein the condition is satisfied by the image when the image has a number of face areas and a size of the face areas that matches the condition.

4. The method of claim 2 wherein the size of a face area is selected from the group consisting of small, medium, and large.

5. The method of claim 2 wherein the number of face areas is selected from the group consisting of one, two, and three or more.

6. The method of claim 1 wherein the objective function factors in an artistic composition rating.

7. The method of claim 6 wherein the objective function factors in an original composition rating.

8. The method of claim 6 wherein the objective function factors in a face preserving composition rating.

9. The method of claim 1 wherein the objective function factors in an artistic composition rating, an original composition rating, and a face preserving composition rating.

10. The method of claim 1 wherein the identifying of a candidate cropping applies a particle swarm optimization algorithm based on the objective function.

11. A computer-readable medium containing instructions for controlling a computer system to identify a cropping for an image, by a method comprising:

selecting an image template with a condition that matches the image; and

identifying a cropping of the image based on a rating of the cropping to attain a goal of the selected image template.

12. The computer-readable medium of claim 11 wherein a condition of an image template indicates number of face areas and size of face areas of the image.

13. The computer-readable medium of claim 12 wherein a condition indicates number of attended areas of the image.

14. The computer-readable medium of claim 11 wherein the rating is determined by an objective function that factors in an artistic composition rating, an original composition rating, and a face preserving composition rating.

15. The computer-readable medium of claim 11 wherein the identifying of a cropping applies a particle swarm optimization algorithm.

16. The computer-readable medium of claim 11 wherein a goal of an image template identifies locations of face areas within a cropping.

17. The computer-readable medium of claim 16 wherein the rating of a cropping indicates closeness of face areas of the cropped image to locations of face areas of the goal of the selected template.

18. A computer system to identify a cropping for an image, comprising:

a image template store having image templates, the image templates having face areas and attended areas, the image templates having associated conditions and goals;

a component that selects an image template with a condition that matches the image; and

a component that identifies a cropping of the image based on a rating of the cropping to attain the goal of the selected image template.

19. The computer system of claim 18 wherein a condition of an image template indicates a number of face areas and number of attended areas.

20. The computer system of claim 18 wherein the rating is determined by an objective function that factors in an artistic composition rating, an original composition rating, and a face preserving composition rating.