gray histogram的用法和樣例：
例句
- The similarity is decided by the Euclidean distance of the gray histograms.
利用各區域灰度直方圖的歐氏距離判定相似區域。 - This paper presents a method of determining the type of vehicle-license-plate based on the gradient histogram and the gray histogram of the image of a vehicle-license-plate.
本文提出一種基於車牌圖像梯度直方圖和灰度直方圖確定車牌類型的方法。
