苹果特征提取，按照灰度化，直方图均衡化，中值滤波，边缘检测，特征提取的顺序来 特征提取中，取得“比例系数”时，选择一张横径图片，序号与之前选择图像的相同-Apple feature extraction, according to grayscale, histogram equalization, median filtering, edge detection, feature extraction feature extraction in order to obtain "