I asked How to count self-intersections in contour on Stack Overflow but it was put on-hold. Could you help me with it, what's wrong?

Edit: I trying to conceive yours remarks:

Your question is also vague. How does a vector of 2d points become a contour? What do you mean by an intersection? – Teepeemm

Contour is a curve, that can be represent by ordered set of points placed in vector. It's standard OpenCV representation. Self-intersections... I can put image to illustrate it.

@RogerRowland - I beg to differ (at least in regards to "a very good one" - it isn't. It is a "how do I do this" and not a "I have tried X, getting these results, what's the problem", which we expect in pretty much all technical Stack Exchange sites. – Oded

It's like if your need to sort array and know only selection sort method. Of course your can take the time and try to invent new methods like quicksort or other.

But I don't see anything wrong with that, to ask in SO about fast and effective alghorithms and related articles and publications for a better understanding.

I don't often ask questions on SO and maybe something has changed recently, but I remember enough questions about search algorithms, and even a set of libraries.

  • It was already linked in the question comments, but everything is here: stackoverflow.com/help/how-to-ask Have you thoroughly searched for an answer before asking your question? Sharing your research helps everyone. Tell us what you found and why it didn’t meet your needs.
    – rlemon
    Sep 20, 2013 at 13:08
  • 1
    @rlemon the closing reason states "tool recommendation", though. I'm sure it's incorrect. Sep 20, 2013 at 13:09
  • 1
    @rlemon OP was sent here by a diamond moderator to ask for clarification.
    – Stijn
    Sep 20, 2013 at 13:09
  • @Stijn I read that comment as well, doesn't negate the fact that everything in the how-to-ask is relevant
    – rlemon
    Sep 20, 2013 at 13:10
  • @JanDvorak The close reason was changed based on the OP's first comment. Sep 20, 2013 at 13:11
  • @JanDvorak yes the close reason is a bit odd, but the comments there still are helpful. I realize he was pointed here, however I still feel that the original comments cover the reasons for closure.
    – rlemon
    Sep 20, 2013 at 13:11
  • 6
    I'd like to give a quick thank you. For, y'know, actually taking the time to improve your post. It helps more than you think.
    – user206222
    Sep 20, 2013 at 13:37
  • What do you mean by "most effectively?" Do you want the fastest performance? Best readability of code? Most likely to succeed in a beer-drinking contest?
    – user102937
    Sep 20, 2013 at 16:24
  • 1
    @RobertHarvey In this case "most effectively" means "fastest performance" primarily. What beer-drinking contest your talking about???
    – victor1234
    Sep 20, 2013 at 18:40
  • Have you thought about adding that detail, and some of the details that Oded asked for below, into your question? If you spent as much time improving your question as you have asking for help, your question might actually get reopened.
    – user102937
    Sep 20, 2013 at 20:06
  • I edited question
    – victor1234
    Sep 21, 2013 at 16:59
  • @RobertHarvey, did you saw may edited question, what wrong with it again?
    – victor1234
    Sep 25, 2013 at 9:56

1 Answer 1


The question shows no effort on your end - I am not saying you made no effort, but that the question doesn't show it.

What research did you do? Where are you stuck? What have you tried? What didn't work?

The question itself also lacks in detail - how is the contour defined? What is the actual problem definition? What data do you have an in what forms?

Now, as for the close reason:

Questions asking us to recommend or find a tool, library or favorite off-site resource are off-topic for Stack Overflow as they tend to attract opinionated answers and spam. Instead, describe the problem and what has been done so far to solve it.

That is due to your first comment:

I asking algorithm description, any links and start points, but not code.

Asking for off-site resources is a no-no. Our format is not suitable for recommendations.

The question still suffers from multiple issues, but the fact that you are looking for a pointer and not an answer is why it was closed with that reason.

  • 1
    Just to add to this: the way to improve the question is to find a library and try something. At that point, if it's still unclear, come back and edit the post to reflect the library you used and the attempt you made. If you (OP) do so, the question will enter the reopening queue, and may likely be reopened.
    – user206222
    Sep 20, 2013 at 13:39
  • OP's question is actually a very good one (for many computer vision applications), even if not a good fit for SO, and it's very difficult to find (i.e. "research") any useful starting points. Is there a SE site for computational geometry? Sep 20, 2013 at 14:35
  • 1
    @RogerRowland - I beg to differ (at least in regards to "a very good one" - it isn't. It is a "how do I do this" and not a "I have tried X, getting these results, what's the problem", which we expect in pretty much all technical Stack Exchange sites.
    – Oded
    Sep 20, 2013 at 14:43
  • 1
    What I was trying (perhaps badly) to say was that the question is one that many researchers in computer vision and image analysis would like to find an answer to. I understand that it's not good for SO but I also appreciate why it was/is difficult for the OP to do any significant research beforehand. I guess I'm looking for a better SE site for such a question. Sep 20, 2013 at 14:48

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .