can one write a research paper which is based on his previous paper I presented a paper in one of the IEEE conferences last month. The paper is still not available in IEEE Xplore. The paper addresses the problem of detection and recovery of X in images. However, the recovery of X needs to be improved both computationally and quality-wise. Currently, I have figured out three different ways of improving the recovery of X. Each of these three recovery methods is better than the one presented in first paper. 

Is it OK to write three papers demonstrating results with each of the new recovery results, given that the detection part will mostly be the same. Am I doing some sort of self-plagiarism here? Please help me understand this.

Further, if I am borrowing detection method from my previous paper, is it required to explain it in detail again or I can just write about it briefly and put a reference?
Writing follow-up papers building on previous work is not at all self-plagiarism. So long as there is a material difference in the main emphasis of the paper, you should be fine. In your case, it sounds like the original article was the introduction of method X, and the follow-up article or articles will be incremental improvements of method X and descriptions of a practical implementation.