The present application relates to an imaging element, comprising: a plurality of photosensitive devices, arranged as pixels and used for receiving light from an imaging object and converting the light into conversion current; a current scaling unit, used for scaling the conversion current to obtain a pixel processing current; a differential current acquisition unit, used for subtracting, from the pixel processing current of each pixel, N times the average value of the pixel processing current of the surrounding pixels of the pixel so as to obtain a differential current; and an analog to digital conversion unit, used for performing analog to digital conversion on the basis of the differential current to obtain edge information of the imaging object. Thus, the edge information of an object may be obtained directly, quickly and accurately.