detect closed shapes formed by several arrays of points

Question

Ilya 2014-1-26

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/113788-detect-closed-shapes-formed-by-several-arrays-of-points

编辑： Ilya 2014-2-23

I plot several arrays containing xy-coordinates of points (using plot(x,y)) and obtain a plot with some curves. The curves form some very distinctive closed shapes (that is, the points describing the curves lie close to each other).

It's needed to "recognize" the closed shapes and to fill them. The coordinates of points forming the shapes and their order are given.

Is it possible without shape recognition tools of the Image Processing Toolbox? If not, then how it can be possibly done with the Image Processing Toolbox?

Any suggestions are welcome!

P.S.: A possible example with 3 closed shapes to detect is given below. The points' coordinates are too lengthy to publish.

2 个评论
显示无隐藏无

Image Analyst 2014-1-26

Probably. Here's a suggestion. Attach screenshots or images so we can visualize what you're talking about.

Ilya 2014-1-27

Yes, that's a valuable comment, thanks!

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Image Analyst 2014-1-27

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/113788-detect-closed-shapes-formed-by-several-arrays-of-points#answer_122349

在 MATLAB Online 中打开

You can do this with the Image Processing Toolbox. There is a function called poly2mask that will give you a binary image that you can then pass in to regionprops to get the centroid.

binaryImage = poly2mask(xVertices, yVertices, rows, columns);
[labeledImage, numberOfRegions] = bwlabel(binaryImage);
measurements = regionprops(labeledImage, 'Centroid');
allCentroids = [measurements.Centroid];
xCentroids = allCentroids(:,1);
yCentroids = allCentroids(:,2);

But I think poly2mask may combine the 3 regions into one. You'd have to try. You can attach your data via a script or .mat file if you want.

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

Ilya 2014-1-28

Still it is more desirable to work with numerical coordinates (due to precision and speed considerations). Additional toolboxes are also undesirable, since I don't use the Image Processing Toolbox somewhere else in my project.

However, very much thanks for the suggestion. May be I'll use it in the end.

请先登录，再进行评论。