Something have been understood that
1.How to split channel, what the meaning of single channel.
2.Convert img from RGB to LAB form
3.Detect the edge
And there are also several points to be solved that correctly linking the external libaray & learning complie the code by CLion but not the command line orz.
ps: Also I need to understand the way of using callback function and how the createTrackbar works.
If you find any grammatical mistake, please comment to me....ahahah....