Tone mapping for low-light video frame enhancement

摘要

A technique is provided for generating sharp, well-exposed, color images from low-light images. A series of under-exposed images is acquired. A mean image is computed and a sum image is generated each based on the series of under-exposed images. Chrominance variables of pixels of the mean image are mapped to chrominance variables of pixels of the sum image. Chrominance values of pixels within the series of under-exposed images are replaced with chrominance values of the sum image. A set of sharp, well-exposed, color images is generated based on the series of under-exposed images with replaced chrominance values.

主权项

1. An image processing method comprising;
obtaining a first underexposed and sharp image of a scene; obtaining a second image relatively well exposed and blurred compared to said first image, nominally of the same scene, wherein said second image is acquired at a different exposure time than said first image; scanning across said first and second images to:
provide a portion of said first image as an input signal to an adaptive filter;provide a corresponding portion of said second image as a desired signal to said adaptive filter; andcalculate filter coefficients for said portion of said images at a given scanning location based on a combination of said input signal, said desired signal and existing filter coefficients for said scanning location; andadaptively filter said input signal based on said filter coefficients to produce an output signal and constructing a first filtered image from said output signal, less blurred than said second image.