US 9,287,316 B2Granted

Systems and methods for mitigating image sensor pixel value clipping

AssigneeSemiconductor Components Industries, LLC

InventorMarko Mlinar

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Abstract

An imaging system may include image sensor pixels, converter circuitry, denoising circuitry, dark current subtraction circuitry, and storage and processing circuitry. The image sensor pixels may generate analog image signals and the converter circuitry may convert the analog image signals into digital pixel values. The denoising circuitry may generate denoised pixel values based on the digital pixel values. The dark current subtraction circuitry may subtract a dark current value from the denoised pixel values. The image sensor pixels and converter circuitry may generate pixel values in multiple color channels. The image sensor pixels may include clear color filter elements for generating clear pixel values. The storage and processing circuitry may determine different black pedestal values for each color channel and may add the black pedestal values to the pixel values from the corresponding color channel to mitigate pixel value clipping in a final image generated by the imaging system.

Claims20

Dependent claims

A method for operating an imaging system comprising processing circuitry and an image sensor having an array of image pixels, the method comprising:

capturing, by the image sensor, first pixel values of a first color in response to image light;
capturing, by the image sensor, second pixel values of a second color that is different from the first color in response to the image light;
with the processing circuitry, determining a first black pedestal value based on the first pixel values;
with the processing circuitry, determining a second black pedestal value based on the second pixel values, wherein the second black pedestal value is different from the first black pedestal value;
with the processing circuitry, adding the first black pedestal value to the first pixel values to generate first corrected pixel values;
with the processing circuitry, adding the second black pedestal value to the second pixel values to generate second corrected pixel values, wherein the first and second corrected pixel values are substantially free from clipping;
and
generating, by the processing circuitry, an output image based on the generated first and second corrected pixel values.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/011,369Filed 27 Aug 2013 · us provisional application
Priority: 19 Apr 2013
Published: US 2014/0313375 A123 Oct 2014
Granted: 15 Mar 2016
Term ends: Not estimatedThe source records don’t support an estimate.

Classification11 codes

H10F 39/024
Manufacture or treatment of image sensors covered by group H10F39/12: of coatings or optical elements
H04N 23/843
For processing colour signals: demosaicing, e.g. interpolating colour pixel values
H04N 25/133
Characterised by the spectral characteristics of the filter elements: including elements passing panchromatic light, e.g. filters passing white light
H04N 25/134
Characterised by the spectral characteristics of the filter elements: based on three different wavelength filter elements