在影像處理中，直方圖等化扮演著重要的角色。為了保護影像邊緣，我們將梯度資訊植基於各種直方圖等化方法中達成具備影像邊緣保護的對比增強方法。我們提出的邊緣保護直方圖建立演算法用於增加邊緣灰階值權重，產生的一維向量被用來輔助原來的轉換函數，因此此演算法可以保存輸入影像的邊緣資訊。實驗結果顯示出再結合了此演算法與原來的轉換函數後，影像的區域對比度被顯著的增加達到96%，除次之外，我們更展現了此演算法植基於各種直方圖等化方法後，具備了更良好的影像的亮度保存結果效果。

Histogram equalization (HE) plays a significant role in image processing. For edge preserving image contrast enhancement, this paper presents a new concept that integrates the gradient information with HE-based methods. We propose an edge preserving histogram construction (EPHC) algorithm to increase the weight of the edge gray levels, after which the 1-D adaptive vector is generated to modify the transform function. Hence, the edge and sharp of the input image can be preserved by the EPHC algorithm. Experimental results show that the local contrast is significantly improved to attain 96% contrast enhancement ratio. Furthermore, we also demonstrate that the image brightness is well maintained by the proposed algorithm.

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