Correcting moving image wavering

• US 8,279,937 B2
• Filed: 04/22/2009
• Issued: 10/02/2012
• Est. Priority Date: 04/22/2008
• Status: Active Grant

• Current Assignee: Pixelplus Co., Ltd.
• Original Assignee: Synergy Innovation Co., Ltd.
• Inventors: Seo, Kang Hoon, Lee, Myung-Soo
• Primary Examiner(s): Ustaris, Joseph
• Assistant Examiner(s): MCINNISH, KEVIN K
• Application Number:
  US12/428,385
• Publication Number:
  US 20090296824A1
• Time in Patent Office: 1,259 Days
• Field of Search: None
• US Class Current: 375/240.24
• CPC Class Codes: H04N 19/51 Motion estimation or motion compensation
• CPC Class Codes: H04N 19/59 involving spatial sub-sampling or interpolation, e.g. alteration of picture size or resolution
• CPC Class Codes: H04N 23/68 for stable pick-up of the scene, e.g. compensating for camera body vibrations
• CPC Class Codes: H04N 23/681 Motion detection

Abstract

Techniques, apparatus and system for correcting moving image wavering are disclosed. An apparatus includes a selecting unit to select at least one reference macroblock from an input image of a first frame and to select at least one search area from an input image of a second frame. The selected at least one search area corresponds to the at least one reference macroblock. The apparatus includes an operating unit to communicate with the selecting unit and to perform a statistical operation by matching the at least one reference macroblock of the first frame to each of search blocks included in the at least one search area of the second frame. The apparatus comprises a vector calculating unit to communicate with the operating unit and to calculate a motion vector to correct an output image of the second frame based on a resultant value of the statistical operation.

Claims

1. An apparatus for correcting moving image wavering, comprising:

a selecting unit to select at least one reference macroblock from an input image of a first frame and to select at least one search area from an input image of a second frame, wherein the selected at least one search area corresponds to the at least one reference macroblock selected from the input image of the first frame;

an operating unit to communicate with the selecting unit and to perform a statistical operation by matching the at least one reference macroblock of the first frame to each of search blocks included in the at least one search area of the second frame;

a vector calculating unit to communicate with the operating unit and to calculate a motion vector to correct an output image of the second frame based on a resultant value of the statistical operation; and

an input processing unit to communicate with the selecting unit to receive images of a first and second frames from an external source, downsize the received images from 50% to 70%, and convert pixel values of the downsized images into gray level values to generate the input image of the first frame and the input image of the second frame,

wherein the operating unit comprises a statistical operation unit to communicate with the first input unit and the second input unit, wherein the statistical operation unit is configured to calculate an operation matrix by performing the statistical operation while shifting the reference macroblock of the first frame in a vertical or horizontal direction such that the reference macroblock corresponds to each search block included in the search area of the second frame, and stores the calculated operation matrix in a memory.

2. The apparatus of claim 1, wherein the at least one search area comprises multiple separated areas spaced apart by a distance from a center of the input image of the second frame.

3. The apparatus of claim 1, wherein the at least one reference macroblock of the first frame is included in at least one search area of the first frame, and the at least one search area of the first frame and the at least one search area of the second frame are positioned at the same coordinates in the input image.

4. The apparatus of claim 1, wherein the selecting unit is configured to store pixel data of the reference macroblock of the first frame and pixel data of the search area of the second frame in a memory.

5. The apparatus of claim 4, wherein the operating unit comprises:

a first input unit to load the pixel data of the reference macroblock of the first frame stored in the memory; and

a second input unit to load the pixel data of the search area of the second frame stored in the memory.

6. The apparatus of claim 5, wherein the vector calculating unit is configured to detect a point having a minimum value from the operation matrix calculated through the statistical operation to calculate position information of a matching block among the search blocks included in the at least one search area of the second frame, and calculate the motion vector based on the position information of the calculated matching block.

7. The apparatus of claim 6, wherein the vector calculating unit uses a spiral searching method to search the value of the point in a spiral direction from a central point of the operation matrix in order to detect the point having the minimum value from the operation matrix.

8. The apparatus of claim 1, further comprising:

a controller to communicate with the selecting unit and the operating unit, wherein the controller is configured to calculate pixel data of a particular macroblock of the first frame and pixel data of a macroblock of the second frame positioned at the same coordinates as the particular macroblock of the first frame, and control the statistical operation performed by the operating unit based on the calculated information.

9. The apparatus of claim 8, wherein the particular macroblock comprises a reference macroblock, and

the controller comprises:

a subtraction operation unit to load the pixel data of the reference macroblock of the first frame and pixel data of a reference macroblock of the second frame and calculate each difference value between pixel values of the reference macroblock of the first frame and the reference macroblock of the second frame;

a position information calculation unit to communicate with the subtraction operation unit to calculate position information of pixels whose difference value is a pre-set reference value or larger; and

a target controller to communicate with the position information calculation unit to control the operating unit to perform the statistical operation only on the pixels corresponding to the calculated position information among pixels of the reference macroblock of the first frame.

10. The apparatus of claim 8, wherein the particular macroblock comprises a reference macroblock;

and

the controller comprises;

a subtraction operation unit to load the pixel data of the reference macroblock of the first frame and pixel data of a reference macroblock of the second frame and calculate each difference value between pixel values of the reference macroblock of the first frame and the reference macroblock of the second frame;

a position information calculation unit to communicate with the subtraction operation unit to calculate position information of a pixel whose different value is the same as or larger than a pre-set first reference value;

a rate calculation unit to communicate with the subtraction operation unit to calculate a rate of the pixel whose difference value is the same as or larger than the pre-set first reference value, in the reference macroblock; and

a target controller to communicate with the position information calculation unit and the rate calculation unit to control the operating unit to perform the statistical operation on only pixels corresponding to the position information among the pixels of the reference macroblock of the first frame when detecting that the calculated rate is smaller than a pre-set second reference value, and control the operating unit to perform the statistical operation on all the pixels of the reference macroblock of the first frame when detecting that the rate is the same as or larger than the pre-set second reference value.

11. The apparatus of claim 1, further comprising:

a controller to communicate with the selecting unit and the operating unit to calculate pixel data of a particular macroblock of the first frame and pixel data of a macroblock of a preceding frame of the first frame positioned at the same coordinates as the particular macroblock of the first frame, and control the statistical operation performed by the operating unit based on the calculated information.

12. The apparatus of claim 1, wherein the input processing unit comprises:

an image receiving unit to receive the images of the first and second frames from an image capturing unit;

an input scaler unit to communicate with the image receiving unit to lower resolution of the received images of the first and second frames; and

an information conversion unit to communicate with the input scaler unit to convert the pixel values of the images processed by the input scaler unit into the gray level values.

13. The apparatus of claim 1, further comprising:

an output scaler unit to receive the images of the first and second frames from an external source and downsize the received images into a size of output images.

14. The apparatus of claim 13, further comprising:

a correcting unit to communicate with the output scaler unit to correct the output image of the second frame downsized by the output scaler unit based on the calculated motion vector.

15. A method for correcting moving image wavering, comprising:

selecting at least one reference macroblock from an input image of a first frame;

selecting at least one search area from an input image of a second frame, wherein the at least one search area corresponds to the at least on reference macroblock;

performing a statistical operation by matching the at least one reference macroblock of the first frame to each of search blocks included in the at least one search area of the second frame; and

calculating a motion vector to correct an output image of the second frame based on a resultant value of the statistical operation;

receiving images of a first and second frames from an external source, downsizing the received images from 50% to 70%, and converting pixel values of the downsized images into gray level values to generate the input image of the first frame and the input image of the second frame,

wherein performing the statistical operation comprises calculating an operation matrix by performing the statistical operation while shifting the reference macroblock of the first frame in a vertical or horizontal direction such that the reference macroblock corresponds to each search block included in the search area of the second frame, and storing the calculated operation matrix in a memory.

16. The method of claim 15, further comprising:

loading pixel data of the at least one reference macroblock of the first frame;

loading at least one reference macroblock of the second frame positioned at the same coordinates as the at least one reference macroblock of the first frame;

calculating information including the loaded pixel data of the at least one reference macroblock of the first frame and the loaded at least one reference macroblock of the second frame; and

controlling the statistical operation based on the calculated information.

17. The method of claim 16, wherein calculating the pixel data comprises:

calculating each difference value between pixel values of the reference macroblocks of the first and second frames;

comparing the calculated difference values to a first reference value; and

calculating position information of pixels whose calculated difference value is the same as or larger than the first reference value.

18. The method of claim 17, wherein controlling the statistical operation comprises:

controlling the statistical operation only on the pixels corresponding to the position information among the pixels of the reference macroblock of the first frame.

19. The method of claim 17, wherein calculating the pixel data comprises:

calculating a rate of the pixels whose calculated difference value is the same as or larger than the first reference value in the reference macroblock; and

comparing the calculated rate to a second reference value, wherein controlling the statistical operation comprises;

controlling the statistical operation by using at least one of resultant information obtained by comparing the calculated rate to the second reference value and the calculated position information.