這篇論文提供一個根基於直方圖等化保持物件邊緣的對比增強方法，本方法除了可以增加對比增強的效果，也可以降低平滑區域在對比增強之後所產生的斑駁現象。有別於過去傳統的方法，可以更有效的分配動態範圍，並且增加影像的視覺品質。

首先，我們先利用Sobel運算子進行測邊，根據測邊的結果，對邊緣的部分進行加權，增加邊緣像素在全部像素的比例，加權過後的直方圖利用累加機率的計算找到分配函數，最後，再進行直方圖重新分配。在實驗結果上，跟過去的方法相比，可以達到更好的效果。

This thesis provides a new method that preserves edge with contrast enhancement for color images. It is based on edge-based histogram method with in different from traditional histogram-based equalizations. Our method not only has good contrast enhancement effect but also avoids artifact.
Fist, we use Sobel operator to detect edges and be use them to update the histogram. Base on updated histogram, the new transformation function is generated.
Experimental results show that the proposed method is better than past methods in image quality.

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