Method and apparatus for short range motion adaptive noise reduction

• US 20080273119A1
• Filed: 05/01/2007
• Published: 11/06/2008
• Est. Priority Date: 05/01/2007
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Lu, Tiehan, Yang, Shengqi
• Granted Patent: US 7,961,972 B2
• Time in Patent Office: Days
• US Class Current: 348/575
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/20012 Locally adaptive
• CPC Class Codes: G06T 5/70 Denoising; Smoothing
• CPC Class Codes: G06T 7/20 Analysis of motion motion estimation for coding, decoding, compressing or decompressing digital video signals H04N19/43, H04N19/51
• CPC Class Codes: H04N 5/142 Edging; Contouring
• CPC Class Codes: H04N 5/144 Movement detection for video coding H04N19/503; analysis of motion in general G06T7/20
• CPC Class Codes: H04N 5/21 Circuitry for suppressing or minimising disturbance, e.g. moiré or halo

Abstract

In one embodiment, the present invention includes a method for generating and storing in a lookup table a first array of next field values for use in generation of weighted pixel values and generating and storing a second array in the lookup table of previous field values for use in generation of the weighted pixel values, determining if motion is present in a pixel of a field under analysis, if the motion is present, performing spatial de-noising using a weighted pixel average of a window of a predetermined size, otherwise performing temporal de-noising using a weighted pixel value between the pixel and a previous pixel using information in the lookup table. Other embodiments are described and claimed.

Claims

1. A method comprising:

generating and storing in a lookup table a first array of next field values for use in generation of weighted pixel values and generating and storing a second array in the lookup table of previous field values for use in generation of the weighted pixel values;

determining if motion is present in a pixel of a field under analysis;

if the motion is present, performing spatial de-noising using a weighted pixel average of a window of a predetermined size, wherein the predetermined size is based on whether a texture or edge is detected for the pixel under analysis;

performing temporal de-noising if the motion is not detected using a weighted pixel value between the pixel and a previous pixel using information in the lookup table; and

outputting updated pixel information from the spatial de-noising or the temporal de-noising and storing the updated pixel information in a storage.

2. The method of claim 1, further comprising calculating a variance value and an average value for a first component of the pixel under analysis.

3. The method of claim 2, further comprising calculating an average value for a second and third component of the pixel.

4. The method of claim 1, further comprising performing the weighted pixel average in a single dimension if an edge is detected, wherein the predetermined size corresponds to a first size.

5. The method of claim 4, further comprising performing the weighted pixel average in a two-dimensional window of a second size if a texture is detected, wherein the second size is greater than the first size.

6. The method of claim 5, further comprising performing the weighted pixel average in a two-dimensional window of a third size, wherein the third size is greater than the second size if no texture is detected.

7. The method of claim 1, further comprising obtaining the weighted pixel value by performing a multiplication of the pixel by a weighted value from the first array and multiplying the previous pixel by a weighted value from the second array and adding a residual value and then performing a right shift operation.

8. The method of claim 7, further comprising obtaining the weighted pixel average of the window of the predetermined size of a plurality of pixels, wherein each pixel is calculated according to:

9. An apparatus comprising:

a processor to generate and store a first array of next field values for use in generation of weighted pixel values and generate and store a second array of previous field values for use in generation of the weighted pixel values, determine if motion is present in a pixel of a field under analysis, if the motion is present, perform spatial de-noising using a weighted pixel average of a window of a predetermined size, wherein the predetermined size is based on whether a texture or edge is detected for the pixel under analysis, perform temporal de-noising if the motion is not detected using a weighted pixel value between the pixel and a previous pixel using information in the first and second arrays, and output updated pixel information from the spatial de-noising or the temporal de-noising and store the updated pixel information in a storage.

10. The apparatus of claim 9, wherein the processor comprises a filter including:

a temporal denoiser;

a lookup table coupled to the temporal denoiser; and

a spatial denoiser.

11. The apparatus of claim 10, further comprising a selector coupled to the temporal denoiser and the spatial denoiser to cause the temporal denoiser or the spatial denoiser to operate on pixel data based on whether motion is detected with regard to the pixel data.

12. The apparatus of claim 11, wherein the spatial denoiser includes:

a variance calculator and an averager;

a texture and edge detector coupled to an output of the variance calculator and the averager; and

a pixel averager to perform a pixel average on a predetermined window size based on an output of the texture and edge detector.

13. The apparatus of claim 12, further comprising a multiplexer to receive outputs of the temporal denoiser and the spatial denoiser, the multiplexer controlled by a signal from the selector.

14. The apparatus of claim 13, wherein the apparatus comprises a video processor.

15. An article comprising a machine readable storage medium including instructions that when executed enable a system to:

generate and store in a lookup table a first array of next field values for use in generation of weighted pixel values and generate and store a second array in the lookup table of previous field values for use in generation of the weighted pixel values;

determine if motion is present in a pixel of a field under analysis;

if the motion is present, perform spatial de-noising using a weighted pixel average of a window of a predetermined size, wherein the predetermined size is based on whether a texture or edge is detected for the pixel under analysis;

perform temporal de-noising if the motion is not detected using a weighted pixel value between the pixel and a previous pixel using information in the lookup table; and

output updated pixel information from the spatial de-noising or the temporal de-noising and store the updated pixel information in a storage.

16. The article of claim 15, wherein the instructions enable the system to calculate a variance value and an average value for a first component of the pixel under analysis.

17. The article of claim 16, wherein the instructions enable the system to calculate an average value for a second and third component of the pixel.