Seam-Based Reduction and Expansion of Images With Color-Weighted Priority

• US 20100027876A1
• Filed: 07/31/2008
• Published: 02/04/2010
• Est. Priority Date: 07/31/2008
• Status: Active Grant

• Current Assignee: Adobe Inc.
• Original Assignee: Adobe Systems Incorporated (Adobe Inc.)
• Inventors: Chien, Jen-Chan, Wang, Jue, Avidan, Shmuel, Intwala, Chintan
• Granted Patent: US 8,290,300 B2
• Time in Patent Office: Days
• US Class Current: 382/162
• CPC Class Codes: G06T 3/04 Context-preserving transformations, e.g. by using an importance map panospheric to cylindrical image transformations G06T3/12
• CPC Class Codes: H04N 1/3872 Repositioning or masking
• CPC Class Codes: H04N 1/393 Enlarging or reducing

Abstract

A system and method for expansion and reduction of images uses an absolute value associated with each pixel of an input image (e.g., a color and/or intensity value) to determine a respective energy value for each pixel. For example, a given color or range of colors (e.g., skin tones, or other high-priority colors) may be assigned higher energy values than other colors and/or color ranges, and may be protected during image reduction and/or expansion. These energy values may be used to determine a cost associated with various seams of the image, which may represent the priority of the seams in the image. One or more low-cost seams may be identified for removal or replication to produce a resized image. The methods may be used in conjunction with an automated skin tone detector or a user interface that allows selection of one or more high priority colors or color ranges.

Claims

1. A system, comprising:

one or more processors; and

a memory coupled to the one or more processors and storing program instructions executable by the one or more processors to implement;

accessing data representing an image;

applying a weighting to one or more pixel values of the image;

determining a respective energy value for each pixel of the image dependent, at least in part, on said weighting;

identifying a seam of the image having a lowest cost, wherein the cost of the seam is dependent on the respective energy values of pixels of the seam; and

performing a resizing operation on the image along the identified seam to produce a resized version of the image.

2. The system of claim 1, wherein the program instructions are further executable to implement repeating said identifying and said performing for a next lowest cost seam until the resized version of the image meets a specified target size or a specified target aspect ratio.

3. The system of claim 1,

wherein the resizing operation comprises a reduction operation;

and

wherein said performing comprises removing the pixels of the seam.

4. The system of claim 1,

wherein the resizing operation comprises an expansion operation;

and

wherein said performing comprises replicating the pixels of the seam and inserting the replicated pixels into the image.

5. The system of claim 1, wherein the cost of the seam is dependent on one or more of:

a sum of the respective energy values of all pixels of the seam, an average of the respective energy values of all pixels of the seam a weighted average of the respective energy values of all pixels of the seam, and a maximum value of the respective energy values of all pixels of the seam.

6. The system of claim 1, wherein said identifying a seam of the image having a lowest cost comprises identifying a shortest path across the image.

7. The system of claim 1, wherein said identifying a seam of the image having a lowest cost comprises applying a dynamic programming technique.

8. The system of claim 1, wherein said applying a weighting comprises applying a weighting factor greater than one to pixels having a value in a specified value range.

9. The system of claim 8, wherein the specified value range comprises pixel values representing one or more colors defined as skin tones.

10. The system of claim 8, wherein the specified value range comprises pixel values automatically determined to represent skin tones.

11. The system of claim 8, wherein the specified value range comprises pixel values in a range specified to be of higher priority than other pixel values by a user.

12. The system of claim 8, wherein the specified value range comprises pixel values within a given difference of a pixel value specified to be of higher priority than other pixel values by a user.

13. The system of claim 1, wherein each of the pixel values represents one or more of:

an absolute color value, and an absolute intensity value.

14. The system of claim 1, wherein the one or more processors comprise at least one of:

a general-purpose central processing unit (CPU) and a graphics processing unit (GPU).

15. A computer-readable storage medium, storing program instructions computer-executable to implement:

accessing data representing an image;

applying a weighting to one or more pixel values of the image;

determining a respective energy value for each pixel of the image dependent, at least in part, on said weighting;

identifying a seam of the image having a lowest cost, wherein the cost of the seam is dependent on the respective energy values of pixels of the seam; and

performing a resizing operation on the image along the identified seam to produce a resized version of the image.

16. The storage medium of claim 15, wherein the program instructions are further executable to implement repeating said identifying and said performing for a next lowest cost seam until the resized version of the image meets a specified target size or a specified target aspect ratio.

17. The storage medium of claim 15,

wherein the resizing operation comprises a reduction operation;

and

wherein said performing comprises removing the pixels of the seam.

18. The storage medium of claim 15,

wherein the resizing operation comprises an expansion operation;

and

wherein said performing comprises replicating the pixels of the seam and inserting the replicated pixels into the image.

19. The storage medium of claim 15, wherein the cost of the seam is dependent on one or more of:

a sum of the respective energy values of all pixels of the seam, an average of the respective energy values of all pixels of the seam, a weighted average of the respective energy values of all pixels of the seam, and a maximum value of the respective energy values of all pixels of the seam.

20. The storage medium of claim 15, wherein said identifying a seam of the image having a lowest cost comprises one or more of:

identifying a shortest path across the image and applying a dynamic programming technique.

21. The storage medium of claim 15, wherein said applying a weighting comprises applying a weighting factor greater than one to pixels having a value in a specified value range.

22. The storage medium of claim 21, wherein the specified value range comprises pixel values representing one or more colors defined as skin tones.

23. The storage medium of claim 21, wherein the specified value range comprises pixel values automatically determined to represent skin tones.

24. The storage medium of claim 21, wherein the specified value range comprises pixel values in a range specified to be of higher priority than other pixel values by a user.

25. The storage medium of claim 21, wherein the specified value range comprises pixel values within a given difference of a pixel value specified to be of higher priority than other pixel values by a user.

26. The storage medium of claim 15, wherein each of the pixel values represents one or more of:

an absolute color value, and an absolute intensity value.

27. A computer-implemented method, comprising:

accessing data representing an image;

applying a weighting to one or more pixel values of the image;

determining a respective energy value for each pixel of the image dependent, at least in part, on said weighting;

identifying a seam of the image having a lowest cost, wherein the cost of the seam is dependent on the respective energy values of pixels of the seam; and

performing a resizing operation on the image along the identified seam to produce a resized version of the image.

28. The method of claim 27, further comprising repeating said identifying and said performing for a next lowest cost seam until the resized version of the image meets a specified target size or a specified target aspect ratio.

29. The method of claim 27,

wherein the resizing operation comprises a reduction operation;

and

wherein said performing comprises removing the pixels of the seam.

30. The method of claim 27,

wherein the resizing operation comprises an expansion operation;

and

wherein said performing comprises replicating the pixels of the seam and inserting the replicated pixels into the image.

31. The method of claim 27, wherein the cost of the seam is dependent on one or more of:

a sum of the respective energy values of all pixels of the seam, an average of the respective energy values of all pixels of the seam, a weighted average of the respective energy values of all pixels of the seam, and a maximum value of the respective energy values of all pixels of the seam.

32. The method of claim 27, wherein said identifying a seam of the image having a lowest cost comprises one or more of:

identifying a shortest path across the image and applying a dynamic programming technique.

33. The method of claim 27, wherein said applying a weighting comprises applying a weighting factor greater than one to pixels having a value in a specified value range.

34. The method of claim 33, wherein the specified value range comprises pixel values representing one or more colors defined as skin tones.

35. The method of claim 33, wherein the specified value range comprises pixel values automatically determined to represent skin tones.

36. The method of claim 33, wherein the specified value range comprises pixel values in a range specified to be of higher priority than other pixel values by a user.

37. The method of claim 33, wherein the specified value range comprises pixel values within a given difference of a pixel value specified to be of higher priority than other pixel values by a user.

38. The method of claim 27, wherein each of the pixel values represents one or more of:

an absolute color value, and an absolute intensity value.