Systems and methods for high dynamic range imaging using crossed polarizers
AssigneeIntrinsic Innovation LLC
InventorsVage Taamazyan, Achuta Kadambi, Kartik Venkataraman
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Abstract
According to one embodiment of the present disclosure, an imaging system includes: an image sensor including a plurality of subpixels grouped into a plurality of pixels; a polarization system including: a rotatable linear polarizer; and a polarizer mask including a plurality of polarizer filters, the polarizer filters being aligned with corresponding ones of the subpixels, the subpixels of a pixel of the plurality of pixels being located behind polarizer filters at different angles of linear polarization; and imaging optics configured to focus light from a scene onto the image sensor.
Claims29
An imaging system comprising:
- an image sensor comprising a plurality of subpixels grouped into a plurality of pixels;
- a polarization system comprising:
- a rotatable linear polarizer;
- and
- a polarizer mask comprising a plurality of polarizer filters, the polarizer filters being aligned with corresponding ones of the subpixels, the subpixels of a pixel of the plurality of pixels being located behind polarizer filters at different angles of linear polarization;
- imaging optics configured to focus light from a scene onto the image sensor;
- and
- a processing circuit configured to perform operations to generate a high-dynamic range image by iteratively determining a polarization angle and exposure settings for a scene being imaged, the operations comprising:
- iteratively modifying a polarizer angle of the rotatable linear polarizer based on a number of overexposed or underexposed subpixels in image sensor data until there are no overexposed or underexposed subpixels in the image sensor data;
- iteratively modifying exposure settings of the image sensor until a dynamic range of the image sensor data matches a dynamic range of a radiance of the scene being imaged;
- and
- generating the high-dynamic range image from final values for the polarizer angle and the exposure settings.
A method for capturing images comprising:
- controlling, by a processing circuit, an image sensor of an imaging system to capture an image,
- the image sensor comprising a plurality of subpixels grouped into a plurality of pixels,
- the imaging system further comprising:
- a polarization system comprising:
- a rotatable linear polarizer;
- and
- a polarizer mask comprising a plurality of polarizer filters, the polarizer filters being aligned with corresponding ones of the subpixels, the subpixels of a pixel of the plurality of pixels being located behind polarizer filters at different angles of linear polarization;
- and
- imaging optics configured to focus light from a scene onto the image sensor;
- performing, by the processing circuit, operations to generate a high-dynamic range image by iteratively determining a polarization angle and exposure settings for a scene being imaged, the operations comprising:
- iteratively modifying a polarizer angle of the rotatable linear polarizer based on a number of overexposed or underexposed subpixels in image sensor data until there are no overexposed or underexposed subpixels in the image sensor data;
- iteratively modifying exposure settings of the image sensor until a dynamic range of the image sensor data matches a dynamic range of a radiance of the scene being imaged;
- and
- generating the high-dynamic range image from final values for the polarizer angle and the exposure settings.
Dependencies are inferred from the claim text.