Method and system for noise reduction in video systems

• US 9,165,345 B2
• Filed: 03/13/2014
• Issued: 10/20/2015
• Est. Priority Date: 03/14/2013
• Status: Active Grant

• Current Assignee: DRS Network & Imaging Systems, LLC (Leonardo S.p.A.)
• Original Assignee: DRS Network & Imaging Systems, LLC (Leonardo S.p.A.)
• Inventors: Hutchison, David C., Blettner, Douglas A., Neal, Henry W., Mendez, Alfredo Jr.
• Primary Examiner(s): Alavi, Amir
• Application Number:
  US14/208,938
• Publication Number:
  US 20140270568A1
• Time in Patent Office: 586 Days
• US Class Current: 1/1
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/20216 Image averaging
• CPC Class Codes: G06T 5/50 using two or more images, e.g. averaging or subtraction
• CPC Class Codes: G06T 5/70 Denoising; Smoothing
• CPC Class Codes: H04N 7/0117 involving conversion of the spatial resolution of the incoming video signal for graphics images G09G2340/0407

Abstract

A system and method of image processing is provided, including implementing adaptive pixel replacement techniques or reducing noise. The method includes obtaining a data map of an image frame, wherein the data map comprises good pixels and bad pixels at locations associated with the data map. The method also includes assigning different techniques to the bad pixels, wherein a first technique is assigned to a first bad pixel and a second technique is assigned to a second bad pixel. The method further includes adjusting information associated with the bad pixels for a chosen technique for each of the bad pixels.

Claims

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

receiving a plurality of input frames including a current frame;

providing the current frame to a first multiplier, to a frame averaging module, and to a first low pass filter;

after the current frame is provided to a first low pass filter, detecting at least a portion of the current frame that includes motion;

generating a mask frame associated with the portion of the current frame that includes the motion detection;

providing the mask frame to a second low pass filter;

after the current frame is provided to the frame averaging module, averaging the current frame and one or more stored frames to generate an averaged current frame;

providing the averaged current frame to a second multiplier; and

generating an output frame based at least in part on the averaged current frame and the current frame after the first multiplier.

2. The method of claim 1 wherein the plurality of current frames includes one or more image frames from an input video stream.

3. The method of claim 1 wherein the first low pass filter is a temporal low pass filter and the second low pass filter is a spatial low pass filter.

4. The method of claim 1, further comprising:

after the mask frame is provided to the second low pass filter, generating a matrix of pixel values associated with motion in one or more pixels in the current frame, and

providing the matrix of pixel values to the first multiplier.

5. The method of claim 4, further comprising:

providing the matrix of pixel values to an inverting module, wherein the inverting module inverts the polarity of the matrix of pixel values.

6. The method of claim 1 wherein averaging the current frame is implemented using an addition technique, an infinite impulse response (IIR) filter, or an alpha blend.

7. The method of claim 1 wherein the motion detection of the portion of the current frame is implemented by comparing the current frame with the one or more stored frames.

8. The method of claim 1, further comprising:

receiving the plurality of input frames from a user; and

providing the output frame to the user.

9. The method of claim 1 wherein the output frame is generated by combining the averaged current frame and the current frame after the first multiplier.

10. The method of claim 1 wherein the mask frame includes a rational number between 0 and 1 for a plurality of pixels in the current frame.

11. The method of claim 1 wherein at least three stored frames are averaged with the current frame to generate the averaged current frame.

12. A method of processing data for an image frame, the method comprising:

receiving a plurality of input frames including a current frame;

providing the current frame to a frame multiplexor, to a frame averaging module, and to a first low pass filter;

after the current frame is provided to a first low pass filter, detecting at least a portion of the current frame that includes motion;

generating a mask frame associated with the portion of the current frame that includes the motion detection;

providing the mask frame to a second low pass filter;

calculating a motion value associated with the mask frame;

comparing the motion value with a threshold;

averaging the current frame and one or more stored frames to generate an averaged current frame;

providing the averaged current frame to the frame multiplexor; and

generating an output frame based at least in part on the averaged current frame and the current frame after the first multiplexor.

13. The method of claim 12 wherein the plurality of current frames includes one or more image frames from an input video stream.

14. The method of claim 12 wherein the first low pass filter is a temporal low pass filter and the second low pass filter is a spatial low pass filter.

15. The method of claim 12 wherein averaging the current frame is implemented using an addition technique, an infinite impulse response (IIR) filter, or an alpha blend.

16. The method of claim 12 wherein the motion detection of the portion of the current frame is implemented by comparing the current frame with the one or more stored frames.

17. The method of claim 12, further comprising:

receiving the plurality of input frames from a user; and

providing the output frame to the user.

18. The method of claim 12 wherein the output frame is generated by combining the averaged current frame and the current frame after the first multiplier.

19. The method of claim 12 wherein the mask frame includes a rational number between 0 and 1 for a plurality of pixels in the current frame.

20. The method of claim 12 wherein at least three stored frames are averaged with the current frame to generate the averaged current frame.