Focal-plane scale space generation with a 6T pixel architecture

Abstract

Aiming at designing a CMOS image sensor that combines high fill factor and focal-plane implementation of instrumental image processing steps, we propose a simple modification in a standard pixel architecture in order to allow for charge redistribution among neighboring pixels. As a result, averaging operations may be performed at the focal plane, and image smoothing based on Gaussian filtering may thus be implemented. By averaging neighboring pixel values, it is also possible to generate intermediate data structures that are required for the computation of Haar-like features. To show that the proposed hardware is suitable for computer vision applications, we present a system-level comparison in which the scale-invariant feature transform (SIFT) algorithm is executed twice: first, on data obtained with a classical Gaussian filtering approach, and then on data generated from the proposed approach. Preliminary schematic and extracted layout pixel simulations are also presented.