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.
本文提出一種基于車(chē)牌圖像梯度直方圖和灰度直方圖確定車(chē)牌類(lèi)型的方法。
