Adaptive lens shading correction
First Claim
Patent Images
1. A method comprising:
- providing a set of lens shading adaptation functions, wherein each of the lens shading adaptation functions corresponds to a respective reference illuminant;
providing a plurality of image frames captured by an image sensor under current illuminant conditions to a hardware image signal processing pipeline;
using an additional image processing pipeline to perform alternative image processing by analyzing a reference frame from a plurality of image frames to select the lens shading adaptation function corresponding to a reference illuminant that most closely matches characteristics of the current illuminant conditions;
adjusting a set of lens shading parameters based upon the selected lens shading adaptation function;
providing the adjusted lens shading parameters to a hardware image signal processing pipeline as feed-forward parameters; and
using the hardware image signal processing pipeline to process the plurality of image frames based on the adjusted lens shading parameters.
1 Assignment
0 Petitions
Accused Products
Abstract
Systems, methods, and devices for applying lens shading correction to image data captured by an image sensor are provided. In one embodiment, multiple lens shading adaptation functions, each modeled based on the response of a color channel to a reference illuminant, are provided. An image frame from the image data may be analyzed to select a lens shading adaptation function corresponding to a reference illuminant that most closely matches a current illuminant. The selected lens shading function may then be used to adjust a set of lens shading parameters.
-
Citations
26 Claims
-
1. A method comprising:
-
providing a set of lens shading adaptation functions, wherein each of the lens shading adaptation functions corresponds to a respective reference illuminant; providing a plurality of image frames captured by an image sensor under current illuminant conditions to a hardware image signal processing pipeline; using an additional image processing pipeline to perform alternative image processing by analyzing a reference frame from a plurality of image frames to select the lens shading adaptation function corresponding to a reference illuminant that most closely matches characteristics of the current illuminant conditions; adjusting a set of lens shading parameters based upon the selected lens shading adaptation function; providing the adjusted lens shading parameters to a hardware image signal processing pipeline as feed-forward parameters; and using the hardware image signal processing pipeline to process the plurality of image frames based on the adjusted lens shading parameters. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A system comprising:
-
a first image processing pipeline configured to receive frames of image data generated by an image sensor and to process the frames of image data to compensate for lens shading fall-off in the frames using a set of lens shading parameters; a feed-forward loop comprising a second image processing pipeline configured to receive, in parallel with the first image processing pipeline, at least one of the frames of image data generated by the image sensor and to select a lens shading adaptation function from a set of available lens shading adaptation functions to compensate for the sensitivity of a lens shading response due to certain wavelengths of light for at least one color channel of the image data; wherein the feed-forward loop is configured to adjust the set of lens shading parameters used by the first image processing pipeline based on the selected lens shading adaptation function. - View Dependent Claims (9, 10, 11, 12, 13)
-
-
14. A method comprising:
-
using a hardware image processing pipeline to receive a plurality of image frames generated by a digital image sensor and to apply lens shading correction to each of the plurality of image frames on a per-pixel basis based upon a set of lens shading gains. using a second image processing pipeline to store at least one image frame from the plurality of image frames and to analyze the at least one image frame, wherein the second image processing pipeline is configured to select a set of lens shading adaptation values based upon the analysis, to adjust the set of lens shading gains based upon the selected set of lens shading adaptation values, and to provide the adjusted set of lens shading gains to the hardware image processing pipeline as feed-forward control parameters. - View Dependent Claims (15, 16, 17, 18)
-
-
19. An electronic device comprising:
-
a processor; a memory containing image analysis software executable by the processor; an image capture device comprising an image sensor configured to capture raw image data; a first image processing pipeline configured to receive the raw image data and to apply lens shading correction to the raw image data using a set of lens shading parameters; and a feed-forward loop comprising a second image processing pipeline configured to receive at least one frame of the raw image data, to analyze the at least one frame using the image analysis software to select a lens shading adaptation function for the at least one frame, and to adjust the lens shading parameters using one or more intermediate transition steps based upon the selected lens shading adaptation function over a plurality of image frames to obtain a final set of adjusted lens shading parameters; wherein the first image processing pipeline is configured to receive the intermediate adjusted lens shading parameters and the final adjusted lens shading parameters as feed-forward outputs from the feed-forward loop and to apply the intermediate and adjusted lens shading parameters to the raw image data. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26)
-
Specification