Invention Grant
- Patent Title: Directional bilateral filtering with improved noise reduction along edges
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Application No.: US17020626Application Date: 2020-09-14
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Publication No.: US10991083B2Publication Date: 2021-04-27
- Inventor: Sheng Lin , Maxim Smirnov , David R. Pope , Farhan Baqai
- Applicant: Apple Inc.
- Applicant Address: US CA Cupertino
- Assignee: Apple Inc.
- Current Assignee: Apple Inc.
- Current Assignee Address: US CA Cupertino
- Agency: Fenwick & West LLP
- Main IPC: G06T5/20
- IPC: G06T5/20 ; G06T7/13 ; G06T5/00 ; H04N9/04

Abstract:
Embodiments relate to a bilateral filter circuit for directional filtering of an image. The directional bilateral filter circuit determines an edge direction and a weight for the edge direction by processing differences between pixel values of pixels in a first block of pixels in the image. The bilateral filter circuit determines non-directional taps for pixels in a second block by processing pixel locations, and determines directional taps by processing differences between pixel values, gradient information for the second block and the edge direction. The bilateral filter circuit determines final filter taps for pixels in the second block by blending corresponding non-directional taps and directional taps using the weight. The bilateral filter circuit obtains a pixel value of a filtered image by multiplying the final filter taps to corresponding pixel values of the pixels in the second block and adding the multiplied values.
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