Method and apparatus for acquiring a set of images illuminated by a flash

Abstract

An electronic imaging device having a plurality of photosensitive cells arranged in an array to form a frame region, the frame region being composed of a plurality of frame sub-regions each frame sub-region corresponding to a sub-set of photosensitive cells, the device comprising an array controller configured to expose each of said frame sub-regions during an exposure duration wherein the exposure of at least some of said frame sub-regions occurs at different times during a total time of exposure of the frame region, a flash unit for illuminating a scene to be imaged during a flash time duration an activator for activating the flash unit to illuminate the scene to be imaged at a flash time delay determined in dependence upon said exposure duration of a frame sub region and the flash time duration; an image data acquisition unit for acquiring a set of frames of the scene wherein the time of occurrence of a flash event within a frame shifts temporally from frame to frame; and an image reconstruction unit for constructing a sequence of images from the frame sub-regions of the acquired frames.

Description

technical field [0001] The invention relates to a method and a device for obtaining a sequence of images illuminated by a flash. In particular, but not exclusively, the present invention relates to methods and apparatus for controlling flashes in cameras equipped with rolling shutters. Background technique [0002] Imaging devices based on digital image sensors operate by capturing optical images and converting them into electronic signals. Such devices are capable of capturing still images and / or video consisting of sequences of images (often referred to as frames). Digital image sensors typically include photosensitive cells (often referred to as photosites) arranged in an array including rows and columns. Photosensitive cells used in imaging devices are usually based on semiconductor technologies capable of converting photons into electrons, such as charge-coupled devices (CCD) or complementary metal-oxide technology (CMOS). Such imaging sensor devices are used in ever...

AI Technical Summary

Problems solved by technology

This difference in exposure leads to effects such as partial lighting (which impairs the quality of the resulting image) and image distortions (such as warping effects)

In the case of frame capture of fast-moving objects, the impairment of image quality is further exacerbated, resulting in image artifacts such as distorted effects

Images