Improving webarkit Trackers

[kalwalt]

Still improving WebARKitTRackers code before create a branch inside the official WebARKitLib repository.

List of added features:

• now OpenCV is a submodule (version 4.7.0) using webarkit/opencv webarkit-4.7.0-exp branch
• Emscripten emsdk 3.1.26
• new webarkit namespace for WebARKit classes/code inside WebARKitLib
• trying to solve issue Uncaught exception in processFrame #11 (but not solved yet)

[kalwalt]

Trying to solve issue #11 this is the error in the console:

webarkit_ES6_wasm.js:1418 Uncaught 341866552 - Exception catching is disabled, this exception cannot be caught. Compile with -sNO_DISABLE_EXCEPTION_CATCHING or -sEXCEPTION_CATCHING_ALLOWED=[..] to catch.
___cxa_throw @ webarkit_ES6_wasm.js:1418
$cv::error(cv::Exception const&) @ 00f16666:0x10d34b
$cv::error(int, std::__2::basic_string<char, std::__2::char_traits<char>, std::__2::allocator<char>> const&, char const*, char const*, int) @ 00f16666:0x10cf7d
$cv::(anonymous namespace)::SparsePyrLKOpticalFlowImpl::calc(cv::_InputArray const&, cv::_InputArray const&, cv::_InputArray const&, cv::_InputOutputArray const&, cv::_OutputArray const&, cv::_OutputArray const&) @ 00f16666:0x20db2c
$cv::calcOpticalFlowPyrLK(cv::_InputArray const&, cv::_InputArray const&, cv::_InputArray const&, cv::_InputOutputArray const&, cv::_OutputArray const&, cv::_OutputArray const&, cv::Size_<int>, int, cv::TermCriteria, int, double) @ 00f16666:0x20d2c0
$WebARKitAkazeTracker::track(cv::Mat&) @ 00f16666:0x10a5b
$WebARKitAkazeTracker::processFrame(cv::Mat&) @ 00f16666:0xc187
$WebARKitAkazeTracker::processFrameData(unsigned char*, unsigned long, unsigned long, ColorSpace) @ 00f16666:0xbab5
$WebARKit::processFrame(emscripten::val, ColorSpace) @ 00f16666:0x1ef92
$emscripten::internal::MethodInvoker<void (WebARKit::*)(emscripten::val, ColorSpace), void, WebARKit*, emscripten::val, ColorSpace>::invoke(void (WebARKit::* const&)(emscripten::val, ColorSpace), WebARKit*, emscripten::_EM_VAL*, ColorSpace) @ 00f16666:0x2062f
WebARKit$processFrame @ VM24:10
processFrame @ WebARKitController.js:105
process_raw @ WebARKitController.js:80
processFrame @ worker.js:53
self.onmessage @ worker.js:16

i need to understand what is wrong in the calcOpticalFlowPyrLK.

[kalwalt]

Note that this exeception occur only for the Akaze tracker, the Orb is not affected... at least doesn't happens to me.

p.s. No this happens also for the orb example.

[kalwalt]

this not happens with webarkit-OCVT with PlanarOrbTracker, but there i use emsdk 3.1.7 not 3.1.26 instead OpenCV is the same 4.5.0. Maybe a bug related to Emscripten?

[kalwalt]

Ok now i tested with emsdk 3.1.7 and the issue #11 still persist, so the Emscripten version is not causing the issue.

[kalwalt]

Maybe because i did a mismatch in the code, (before i make changes in the main branch and after i merged in this) now wihile rebuilding the whole project it seems that the unchaught exception is disappeared. There are a lot to be improved, i.e. in the akaze example it can track but if you remove the trackable image the image displayed stay in place blinking, maybe something not correct in processFrameData with the shared_ptr?

[kalwalt]

latest commit try to improve the code and to completely to solve issue #11. It a bit better but not full solved. AT least with the orb example is more difficult to catch the Uncaught exception.

[kalwalt]

Now OpenCV is a as a git submodule (webarkit/opencv) with branch webarkit-4.7.0-exp. It's a modified version with applied the patch as said in this opencv issue comment.
We are testing OpenCV 4.7.0 and emsdk 3.1.26.