System and method for reducing noise in images

• US 7,319,494 B2
• Filed: 05/16/2005
• Issued: 01/15/2008
• Est. Priority Date: 09/10/2001
• Status: Expired due to Term

• Current Assignee: Jaldi Semiconductor Corporation (Pixelworks Incorporated)
• Original Assignee: Jaldi Semiconductor Corporation (Pixelworks Incorporated)
• Inventors: Elias, Andrew, Wredenhagen, G. Finn
• Primary Examiner(s): LEE, MICHAEL
• Application Number:
  US11/131,098
• Publication Number:
  US 20050243205A1
• Time in Patent Office: 974 Days
• Field of Search: 348/606, 348/607, 348/617, 348/618, 348/619, 348/622, 348/625, 382/190, 382/195, 382/203, 382/209, 382/199, 382/282, 382/197
• US Class Current: 348/606
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/20192 Edge enhancement; Edge preservation
• CPC Class Codes: G06T 5/20 using local operators
• CPC Class Codes: G06T 5/70 Denoising; Smoothing
• CPC Class Codes: G06T 7/40 Analysis of texture depth or shape recovery from texture G06T7/529
• CPC Class Codes: H04N 5/208 for compensating for attenuation of high frequency components, e.g. crispening, aperture distortion correction
• CPC Class Codes: H04N 5/21 Circuitry for suppressing or minimising disturbance, e.g. moiré or halo

Abstract

A method is provided for selecting a filter for interpolating a target pixel for reducing noise in an image. The method comprises the following steps. A plurality of pixels along a predetermined contour is compared with a plurality of predefined patterns. The patterns represent visually significant patterns possible along said contour. A filter is selected from a predefined set of filters in accordance with the results of the comparison.

Claims

1. An apparatus, comprising:

a noise estimation block to estimate noise in an image;

a contouring block to select a contour responsive to the noise; and

a texture classification block to classify the contour into at least one pattern.

2. The apparatus of claim 1 where the noise estimation block is adapted to maintain a histogram of the noise in the image.

3. The apparatus of claim 1 where the noise estimation block is adapted select one from among a plurality of filters responsive to the at least one pattern.

4. The apparatus of claim 1 where the contouring block is reconfigurable.

5. The apparatus of claim 1 where the contouring block is adapted to select a collection of pixels among a plurality of neighboring pixels.

6. The apparatus of claim 5 where the collection of pixels is a collection of pixels having like amplitudes.

7. The apparatus of claim 5

where the contouring block is adapted to compare each neighboring pixel with a threshold;

and

where the contouring block is adapted to select the collection of pixels responsive to the comparison.

8. The apparatus of claim 5 where the contouring block is adapted to classify the collection of pixels into one of a plurality of contours.

9. The apparatus of claim 1 where the texture classification block is includes:

a texture type block to detect the pattern responsive to the noise;

a texture degree block to determine a severity of the pattern in the contour; and

a texture correlation block to correlate deviations between a plurality of pixels in the contour.

10. An apparatus comprising:

means for estimating noise in an image;

means for selecting a contour responsive to the noise; and

means for classifying the contour into a pattern.

11. The apparatus of claim 10 where the means for estimating noise includes means for creating and maintaining a histogram of the noise in the image.

12. The apparatus of claim 10 where the means for estimating noise includes means for selecting one from among a plurality of filters responsive to the pattern.

13. The apparatus of claim 10 where the means for selecting reconfigurable.

14. The apparatus of claim 10 where the means for selecting includes means for selecting a collection of pixels among a plurality of neighboring pixels.

15. The apparatus of claim 14 where the means for selecting the collection of pixels is adapted to select a collection of pixels having like amplitudes.

16. The apparatus of claim 14 where the means for selecting includes:

means for comparing each neighboring pixel with a threshold; and

means for selecting the collection of pixels responsive to the means for comparing.

17. The apparatus of claim 14 where the means for selecting includes means for classifying the collection of pixels into one of a plurality of contours.

18. The apparatus of claim 10 where the means for classifying includes:

means for detecting the pattern responsive to the noise;

means for determining a severity of the pattern in the contour; and

means for correlating deviations between a plurality of pixels in the contour.