METHOD AND DEVICE FOR PROCESSING IMAGE DATA

• US 20150235353A1
• Filed: 02/19/2015
• Published: 08/20/2015
• Est. Priority Date: 02/19/2014
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: YI, Ji-Young, PARK, Hyun-Hee, CHO, Jae-Hun, KIM, Jong-Ho, PARK, Kee-hyon, LEE, Yong-man, HAN, Dong-kyoon
• Granted Patent: US 9,830,692 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06T 2207/20208 High dynamic range [HDR] image processing
• CPC Class Codes: G06T 2207/20216 Image averaging
• CPC Class Codes: G06T 5/40 using histogram techniques
• CPC Class Codes: G06T 5/50 using two or more images, e.g. averaging or subtraction
• CPC Class Codes: G06T 5/92 based on global image properties
• CPC Class Codes: G06V 10/60 relating to illumination properties, e.g. using a reflectance or lighting model

Abstract

Provided are a method and a device for processing image data. The method includes: determining first characteristic values respectively of a plurality of regions of a first image by sequentially calculating, for each of the plurality of regions, characteristic values corresponding to each of pixel values of pixels included in each of the plurality of regions while sequentially receiving the pixel values of the pixels; obtaining, based on the determined first characteristic values, an illumination image related to a second image that is a following image of the first image; and modifying, based on the obtained illumination image, the second image.

Claims

1. A method of processing image data, the method comprising:

determining first characteristic values respectively of a plurality of regions of a first image by sequentially calculating, for each of the plurality of regions, characteristic values corresponding to each of pixel values of pixels included in each of the plurality of regions while sequentially receiving the pixel values of the pixels;

obtaining, based on the determined first characteristic values, an illumination image related to a second image that is a following image of the first image; and

modifying, based on the obtained illumination image, the second image.

2. The method of claim 1, wherein the determining the first characteristic values comprises:

obtaining a first pixel value of a first pixel included in a first region from among the plurality of regions of the first image while sequentially receiving pixel values of pixels included in the first region;

obtaining a second pixel value of a second pixel included in the first region while sequentially receiving the pixel values of the pixels included in the first region;

determining a cumulative characteristic value based on a weighted sum of the first pixel value and the second pixel value;

obtaining a third pixel value of a third pixel included in the first region while sequentially receiving the pixel values of the pixels included in the first region; and

updating the cumulative characteristic value based on a weighed sum of the cumulative characteristic value and the third pixel value.

3. The method of claim 1, wherein the obtaining the illumination image comprises obtaining a pixel value of an illumination pixel included in the illumination image based on first characteristic values, among the determined first characteristic values, of a predetermined number of regions, which are most adjacent to the illumination pixel, from among the plurality of regions.

4. The method of claim 3, wherein the obtaining the illumination image further comprises performing linear interpolation on intervals between the illumination pixel and the predetermined number of regions.

5. The method of claim 1, further comprising:

determining second characteristic values respectively of a plurality of regions of a second image by sequentially calculating, for each of the plurality of regions, characteristic values of each of pixel values of pixels included in each of the plurality of regions while sequentially receiving the pixel values of the pixels; and

determining third characteristic values respectively of corresponding regions, from among the plurality of regions of the first image and the plurality of regions of the second image, based respectively on the first characteristic values and the second characteristic values of the corresponding regions,

wherein the obtaining the illumination image is performed based on the third characteristic values determined based on the first characteristic values.

6. The method of claim 5, wherein the modifying comprises:

determining reflectance pixel values based on the third characteristic values and the pixel values of the pixels included in each of the plurality of regions of the second image;

determining output pixel values based on a weighted sum of the third characteristic values and the reflectance pixel values; and

modifying the second image based on the determined output pixel values.

7. The method of claim 1, further comprising storing the determined first characteristic values in a register.

8. The method of claim 1, wherein the modifying comprises:

determining whether at least a predetermined proportion of the pixel values of the pixels included in each of the plurality of regions of the first image are within a predetermined range; and

determining whether to modify the second image based on a result of the determining whether the at least the predetermined proportion of the pixel values are within the predetermined range.

9. The method of claim 8, wherein the determining whether to modify the second image comprises skipping the modifying of the second image in response to determining that the at least the predetermined proportion of the pixel values are within the predetermined range.

10. The method of claim 1, wherein the first image is an image of a previous frame and the second image is an image of a current frame.

20. A non-transitory computer-readable recording medium having recorded thereon a program, which when executed by a computer, performs the method of claim 1.

11. A device for processing image data, the device comprising:

a characteristic value determiner configured to determine first characteristic values respectively of a plurality of regions of a first image by sequentially calculating, for each of the plurality of regions, characteristic values of each of pixel values of pixels included in each of the plurality of regions while sequentially receiving the pixel values of the pixels included;

an illumination image obtainer configured to obtain, based on the determined first characteristic values, an illumination image related to the first image; and

an image modifier that modifies, based on the obtained illumination image, a second image that is a following image of the first image.

12. The device of claim 11, wherein the characteristic value determiner is configured to:

obtain a first pixel value of a first pixel included in a first region from among the plurality of regions of the first image while sequentially receiving pixel values of pixels included in the first region;

obtain a second pixel value of a second pixel included in the first region while sequentially receiving the pixel values of the pixels included in the first region; and

determine a characteristic value of the first region based on the first pixel value and the second pixel value.

13. The device of claim 12, wherein the illumination image obtainer is configured to obtain a pixel value of an illumination pixel included in the illumination image based on first characteristic values, among the determined first characteristic values, of a predetermined number of regions, which are most adjacent to the illumination pixel, from among the plurality of regions.

14. The device claim 11, wherein:

the characteristic value determiner is configured to determine second characteristic values respectively of a plurality of regions of a second image by sequentially calculating, for each of the plurality of regions, characteristic values corresponding to each of pixel values of pixels included in each of the plurality of regions while sequentially receiving the pixel values of the pixels, and to determine third characteristic values respectively of corresponding regions, from among the plurality of regions of the first image and the plurality of regions of the second image, based respectively on the first characteristic values and the second characteristic values of the corresponding regions; and

the illumination image obtainer is configured to obtain the illumination image based on the third characteristic values determined based on the first characteristic values.

15. The device of claim 14, wherein the image modifier is configured to:

determine reflectance pixel values based on the third characteristic values and the pixel values of the pixels included in each of the plurality of regions of the second image;

determine output pixel values based on a weighted sum of the third characteristic values and the reflectance pixel values; and

modify the second image based on the determined output pixel values.

16. The device of claim 11, further comprising a register configured to store the determined first characteristic values.

17. The device of claim 11, wherein the image modifier is configured to:

determine whether at least a predetermined proportion of the pixel values of the pixels included in each of the plurality of regions of the first image are within a predetermined range; and

determine whether to modify the second image based on a result of the determining whether the at least the predetermined proportion of the pixel values are within the predetermined range.

18. A method of processing image data, the method comprising:

obtaining illumination values respectively corresponding to each of a plurality of regions of a previous frame image based on the previous frame image, and storing the obtained illumination values in a register;

obtaining an illumination image of the previous frame image based on the obtained illumination values; and

updating a current frame image by performing a retinex operation on the obtained illumination image and the current frame image.

19. The method of claim 18, further comprising:

determining whether a scene change occurs from the previous frame image to the current frame image, based on the previous frame image and the current frame image,

wherein the updating the current frame image is performed by reflecting the scene change in the current frame image in response to determining that the scene change occurs.