In this paper, an effective method, named the brightness preserving weighted dynamic range histogram equalization\n(BPWDRHE), is proposed for contrast enhancement. Although histogram equalization (HE) is a universal method, it is\nnot suitable for consumer electronic products because this method cannot preserve the overall brightness. Therefore,\nthe output images have an unnatural looking and more visual artifacts. An extension of the approach based on the\nbrightness preserving bi-histogram equalization method, the BPWDRHE used the weighted within-class variance\nas the novel algorithm in separating an original histogram. Unlike others using the average or the median of gray\nlevels, the proposed method determined gray-scale values as break points based on the within-class variance to\nminimize the total squared error of each sub-histogram corresponding to the brightness shift when equalizing them\nindependently. As a result, the contrast of both overall image and local details was enhanced adequately. The\nexperimental results are presented and compared to other brightness preserving methods
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