Design of Auto Exposure Unit Based On 2-Way Histogram Equalization

Authors: Junghwan Choi, Seongsoo Lee

Abstract:

Histogram equalization is often used in image enhancement, but it can be also used in auto exposure. However, conventional histogram equalization does not work well when many pixels are concentrated in a narrow luminance range.This paper proposes an auto exposure method based on 2-way histogram equalization. Two cumulative distribution functions are used, where one is from dark to bright and the other is from bright to dark. In this paper, the proposed auto exposure method is also designed and implemented for image signal processors with full-HD images.

Keywords: Histogram equalization, Auto exposure, Image signal processor, Low-cost, Full HD Video.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1086649

References:

[1] Y. Kim, “Contrast Enhancement Using Brightness Preserving Bi-Histogram Equalization,”IEEE Transactions on Consumer Electronics, vol. 43, no. 1, pp. 1-8, Feb. 1997
[2] Y. Wan, Q. Chen, and B.M. Zhang, area dualistic sub-image histogram equalization method Transactions on Consumer Electronics 1999.
[3] S. D. Chen and A. R.Ramli, Mean-Separate Histogram Equalization for Scalable Brightness Preservation,”IEEE Transactions on Consumer Electronics 4, pp. 1301-1309, Dec. 2003
[4] T. Arici, S. Dikbas, and Y. Altunbasak, Framework and Its Application for Image Contrast Enhan Transactions on Image Processing 2009.