Image restoration device and image restoration method

• US 20110141322A1
• Filed: 12/14/2009
• Published: 06/16/2011
• Est. Priority Date: 12/14/2009
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Sang-hoon, Kim, Tae-chan, Paik, Joon-ki
• Granted Patent: US 8,339,481 B2
• Time in Patent Office: Days
• US Class Current: 348/241
• CPC Class Codes: G06T 5/003 Deblurring; Sharpening vibration or motion blur correction for cameras comprising an electronic image sensor H04N23/682
• CPC Class Codes: G06T 5/20 using local operators
• CPC Class Codes: G06T 5/73 Deblurring; Sharpening

Abstract

An image restoration method includes receiving an externally input image signal, generating a filtered image signal by filtering the input image signal, and generating a restored image signal by calculating a weighted average of the input image signal and the filtered image signal. Such a method may be implemented using an image restoration device including an image filtering unit adapted generated the filtered image signal, and an image mixing unit adapted to generate the restored image signal. More particularly, the restored image signal may be generated using weighting factors calculated based on the input image signal, by calculating a local variance of pixels in the input image signal, and calculating the weighting factor for each of the pixels based on the local variance of each of the pixels.

Claims

1. An image restoration device adapted to receive an image signal, the device comprising:

an image filtering unit adapted to filter the image signal and output the filtered image signal; and

an image mixing unit adapted to receive the image signal and the filtered image signal, to calculate a weighted average of the image signal and the filtered image signal, and to output the weighted average as a restored image signal.

2. The image restoration device as claimed in claim 1, wherein the image filtering unit includes a constrained least square (CLS) filter.

3. The image restoration device as claimed in claim 2, wherein the CLS filter is a finite impulse response (FIR) filter.

4. The image restoration device as claimed in claim 1, further comprising a weighting factor calculating unit adapted:

to receive the image signal,

to calculate a local variance of pixels in the image signal,

to calculate weighting factors for each of the pixels based on the local variance of each of the pixels, and

to output the weighting factors to the image mixing unit.

5. The image restoration device as claimed in claim 4, wherein the image mixing unit is adapted to calculate the weighted average of the image signal and the filtered image signal based on the weighting factors input by the weighting factor calculating unit.

6. The image restoration device as claimed in claim 4, wherein the weighting factor calculating unit is adapted to calculate the local variance of each of the pixels according to an equation

7. The image restoration device as claimed in claim 6, wherein the weighting factor calculating unit is adapted to calculate the local mean of the region S according to an equation

8. The image restoration device as claimed in claim 7, wherein the weighting factor calculating unit is adapted to calculate the weighting factors of each of the pixels according to an equation

9. The image restoration device as claimed in claim 4, wherein the weighting factor calculating unit includes a finite impulse response (FIR) filter.

10. An imaging system, comprising:

an imaging device adapted to capture an image of an object, to generate an image signal of the captured image, and to output the image signal; and

an image signal processing device adapted to receive the image signal from the imaging device,

wherein the image signal processing device includes;

an image filtering unit adapted to filter the image signal and output the filtered image signal; and

an image mixing unit adapted to receive the image signal and the filtered image signal, to calculate a weighted average of the image signal and the filtered image signal, and to output the weighted average as a restored image signal.

11. An image restoration method, comprising:

receiving an externally input image signal;

generating a filtered image signal by filtering the input image signal; and

generating a restored image signal by calculating a weighted average of the input image signal and the filtered image signal.

12. The method as claimed in claim 11, further comprising:

calculating weighting factors based on the input image signal, wherein calculating the weighting factors includes;

calculating a local variance of pixels in the input image signal; and

calculating the weighting factor for each of the pixels based on the local variance of each of the pixels,

wherein generating the restored image signal includes calculating the weighted average of the input image signal and the filtered image signal based on the weighting factors for the pixels.

13. The method as claimed in claim 12, wherein calculating the local variance of each of the pixels includes calculating a local mean of a region to which the respective pixel belongs.

14. The method as claimed in claim 13, wherein calculating the local mean of the respective region includes calculating the local mean according to an equation

15. The method as claimed in claim 12, wherein calculating the local variance of each of the pixels includes calculating the local variance of each of the pixels according to an equation