Finds a polygon enclosing the user defined mask. Inverse of poly2mask :).
Updated 25 Jul 2011

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This functions goal is to find a polygon which enclosures a user supplied mask. It's a kind of a complementary of Matlab poly2mask function. The difference is that all contour points are returned- without missing points for linearly related points. In order to get a 100% complementary of poly2mask all points inside straight lines should be omitted. In my case I actually need all those points, as index of ROI.
Combining mask2poly with poly2mask the user can produce a mask from a contour (line with X and Y coordinates), and vise-versa.

Cite As

Nikolay S. (2024). mask2poly (, MATLAB Central File Exchange. Retrieved .

MATLAB Release Compatibility
Created with R2011a
Compatible with any release
Platform Compatibility
Windows macOS Linux
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Version Published Release Notes

Minor change

---------------2011-07-25----------- Ordering points according to rule of "nearest point" (accurate but slow) added.

Minor changes, according to Daniel's remarks.

An option to reorder the points so it will define a CW contour. Now you can plot the contours with line connecting the dots, without getting crazy lines all over the mask. Enable the "flagCW".

- "Inner" and "Outer" options replaced isIndex option
- Diff based edges calculation replaced contour based calculation for "Inner" and "Outer" options, which resulted in ~x3 shorter run time.