Image sensing system

Abstract

According to an aspect, there is provided an image sensing system comprising: a rolling shutter image sensor comprising an array of pixels in a frame arranged into a plurality of image lines extending along a width direction, and distributed in a scanning direction which is perpendicular to the width direction, wherein the rolling shutter image sensor is configured to scan the frame by sequentially scanning each image line along the scanning direction, wherein scanning each image line includes making the pixels in each image line sensitive to light for a predetermined exposure time, and then determining an intensity readout for each pixel of the respective image line; a lens system configured to project at least two similar outgoing images of an object onto the image sensor, the outgoing images offset from one another in the scanning direction, wherein the outgoing images are projected onto the image sensor such that each pixel of an outgoing image corresponding to a position on the object matches a pixel or group of pixels of another outgoing image corresponding to the respective position on the object; a light generator configured to generate at least two different colours of light, defined by different wavelengths, to illuminate the object; a timing module configured to control the light generator to sequentially generate at least two different colours of light during scanning of a single frame; and a processor configured to identify matched pixels of different outgoing images corresponding to a respective position on the object, and to resolve the colour spectrum of the respective position of the object based on the intensity readout of each matched pixel and the colours of light that the respective matched pixels were exposed to while they were sensitive.