Commit Graph

14 Commits

Author SHA1 Message Date
Mironov Arseny
b964943517
Merge pull request #25607 from Fest1veNapkin:imgproc_approx_bounding_poly
Add a new function that approximates the polygon bounding a convex hull with a certain number of sides #25607

merge PR with <https://github.com/opencv/opencv_extra/pull/1179>

This PR is based on the paper [View Frustum Optimization To Maximize Object’s Image Area](https://citeseerx.ist.psu.edu/document?repid=rep1&type=pdf&doi=1fbd43f3827fffeb76641a9c5ab5b625eb5a75ba).

# Problem
I needed to reduce the number of vertices of the convex hull so that the additional area was minimal, andall vertices of the original contour enter the new contour.

![image](https://github.com/Fest1veNapkin/opencv/assets/98156294/efac35f6-b8f0-46ec-91e4-60800432620c)

![image](https://github.com/Fest1veNapkin/opencv/assets/98156294/2292d9d7-1c10-49c9-8489-23221b4b28f7)

# Description
Initially in the contour of n vertices, at each stage we consider the intersection points of the lines formed by each adjacent edges. Each of these intersection points will form a triangle with vertices through which lines pass. Let's choose a triangle with the minimum area and merge the two vertices at the intersection point. We continue until there are more vertices than the specified number of sides of the approximated polygon.
![image](https://github.com/Fest1veNapkin/opencv/assets/98156294/b87b21c4-112e-450d-a776-2a120048ca30)

# Complexity:
Using a std::priority_queue or std::set  time complexity is **(O(n\*ln(n))**, memory **O(n)**,
n - number of vertices in convex hull.

count of sides - the number of points by which we must reduce.
![image](https://github.com/Fest1veNapkin/opencv/assets/98156294/31ad5562-a67d-4e3c-bdc2-29f8b52caf88)

## Comment
If epsilon_percentage more 0, algorithm can return more values than _side_.
Algorithm returns OutputArray. If OutputArray.type() equals 0, algorithm returns values with InputArray.type().
New test uses image which are not in opencv_extra, needs to be added.

### Pull Request Readiness Checklist

See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request

- [ ] I agree to contribute to the project under Apache 2 License.
- [ ] To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV
- [ ] The PR is proposed to the proper branch
- [ ] There is a reference to the original bug report and related work
- [ ] There is accuracy test, performance test and test data in opencv_extra repository, if applicable
      Patch to opencv_extra has the same branch name.
- [ ] The feature is well documented and sample code can be built with the project CMake
2024-07-09 17:11:23 +03:00
Kumataro
602caa9cd6
Merge pull request #21937 from Kumataro:4.x-fix-21911
* Fix warnings for clang15

* Fix warnings: Remove unnecessary code

* Fix warnings: Remove unnecessary code
2022-05-13 17:32:05 +00:00
Alexander Alekhin
8b4fa2605e Merge remote-tracking branch 'upstream/3.4' into merge-3.4 2021-12-03 12:32:49 +00:00
yuki takehara
a6277370ca
Merge pull request #21107 from take1014:remove_assert_21038
resolves #21038

* remove C assert

* revert C header

* fix several points in review

* fix test_ds.cpp
2021-11-27 18:34:52 +00:00
Brian Wignall
f9c514b391 Fix spelling typos
backport commit 659ffaddb4
2019-12-27 12:46:53 +00:00
Brian Wignall
659ffaddb4 Fix spelling typos 2019-12-26 06:45:03 -05:00
Alexander Alekhin
92b9888837 Merge remote-tracking branch 'upstream/3.4' into merge-3.4 2019-12-12 13:02:19 +03:00
RAJKIRAN NATARAJAN
b9435b9e38 Merge pull request #16094 from saskatchewancatch:issue-16053
* Add eps error checking for approxPolyDP to allow sensible values only
for epsilon value of Douglas-Peucker algorithm.

* Review changes for PR
2019-12-09 22:24:35 +03:00
Vadim Pisarevsky
0f622206e4
completely new C++ persistence implementation (#13011)
* integrated the new C++ persistence; removed old persistence; most of OpenCV compiles fine! the tests have not been run yet

* fixed multiple bugs in the new C++ persistence

* fixed raw size of the parsed empty sequences

* [temporarily] excluded obsolete applications traincascade and createsamples from build

* fixed several compiler warnings and multiple test failures

* undo changes in cocoa window rendering (that was fixed in another PR)

* fixed more compile warnings and the remaining test failures (hopefully)

* trying to fix the last little warning
2018-11-02 00:27:06 +03:00
Alexander Alekhin
8a3c394d6a don't use constructors for C API structures 2018-09-06 14:34:16 +03:00
Alexander Alekhin
4a297a2443 ts: refactor OpenCV tests
- removed tr1 usage (dropped in C++17)
- moved includes of vector/map/iostream/limits into ts.hpp
- require opencv_test + anonymous namespace (added compile check)
- fixed norm() usage (must be from cvtest::norm for checks) and other conflict functions
- added missing license headers
2018-02-03 19:39:47 +00:00
Roman Donchenko
e9a28f66ee Normalized file endings. 2013-08-21 18:59:25 +04:00
OpenCV Buildbot
04384a71e4 Normalize line endings and whitespace 2012-10-17 15:32:23 +04:00
Vadim Pisarevsky
061b49e0b2 reworked nearly all of the OpenCV tests (except for opencv_gpu tests) - they now use the Google Test engine. 2011-02-09 20:55:11 +00:00