US 2016/0366331 A1 · METHODS AND DEVICES FOR CORRECTION OF CAMERA MODULE SENSITIVITY AND FLASH COLOR VARIATION

Abstract

A device and a method for dynamically correcting camera module sensitivity variation using face data are disclosed. The method includes accessing a digital image frame of a scene where the digital image frame originates from a camera module. In response to detection of a face area in the digital image frame, a face chromaticity is calculated from the face area detected in the digital image frame by a processor. The method further includes determining a lighting condition at the scene associated with the digital image frame. Further, the method includes comparing the face chromaticity with a reference face chromaticity associated with the lighting condition to determine a chromaticity gain shift. Thereafter, the method includes correcting a gray point curve of the camera module based on the chromaticity gain shift to obtain a corrected gray point curve of the camera module.

Claims20

Dependent claims

A method, comprising:

accessing a digital image frame of a scene, the digital image frame originating from a camera module;
in response to detecting a face area in the digital image frame, performing by a processor:
calculating a face chromaticity from the face area detected in the digital image frame;
determining a lighting condition at the scene associated with the digital image frame;
and
comparing the face chromaticity with a reference face chromaticity for the lighting condition to determine a chromaticity gain shift;
and
calibrating a gray point curve of the camera module based on the chromaticity gain shift to obtain a calibrated gray point curve for the camera module.

5 more elements

A device, comprising:

a camera module for generating a digital image frame of a scene;
at least one memory comprising image processing instructions;
and
at least one processor communicably coupled with the camera module and the at least one memory, the at least one processor configured to execute the image processing instructions to at least perform:
accessing the digital image frame generated from the camera module for face detection in the digital image frame;
in response to a detection of a face area in the digital image frame:
calculating a face chromaticity from the face area detected in the digital image frame;
determining a lighting condition at the scene associated with the digital image frame;
and
comparing the face chromaticity with a reference face chromaticity for the lighting condition to determine a chromaticity gain shift;
and
calibrating a gray point curve of the camera module based on the chromaticity gain shift to obtain a calibrated gray point curve for the camera module.

9 more elements

A device, comprising:

a camera module for generating a first digital image frame of a scene without using a flash illumination and generating a second digital image frame of the scene by using the flash illumination, the flash illumination generated from a flash module;
at least one memory comprising image processing instructions;
and
at least one processor communicably coupled with the camera module and the at least one memory, the at least one processor configured to execute the image processing instructions to at least perform:
accessing the first digital image frame and the second digital image frame;
in response to a detection of a face area in the first digital image frame and a face area in the second digital image frame:
calculating a first face chromaticity of the face area detected in the first digital image frame and a second face chromaticity of the face area detected in the second digital image frame;
determining a reference flash face chromaticity for a reference flash module based on the first face chromaticity;
and
calculating a chromaticity gain shift between the reference flash face chromaticity and the second face chromaticity;
and
calibrating a flash gray point for the flash module based on a reference flash gray point and the chromaticity gain shift to obtain a calibrated flash gray point for the flash module in the camera module.

9 more elements

Dependencies are inferred from the claim text.

Methods and devices for correction of camera module sensitivity and flash color variation

Life of this patent

Methods and devices for correction of camera module sensitivity and flash color variation

Life of this patent

Abstract

Claims20