A New Investigation on Edge detection Filters Operation for Feature Extraction under Histogram Equalization Effect

A new investigation about one of the most important preprocessing steps so-called histogram equalization is proposed in this paper. We are about to probe effect of histogram equalization on operation of some useful edge detection filters. First for this reason, we applied specific edge detection filter on sample image, solely. For the next time before applying edge detector, we used histogram equalization to expand the gray level range of sample image and then applied edge detector. We have compared the consequences by means of standard deviation to mean ratio. It is demonstrated that minimum values for this ratio exhibit better gray level expansion and smoother edges. Finally, we have made a practical guide for researchers by our experimental results to choose proper edge detection filter for their special feature extraction work in presence of histogram equalization.