Commit Graph

2368 Commits

Author SHA1 Message Date
Vadim Pisarevsky
1d45726f47 Merge pull request #7588 from terfendail:ovx_medianblur 2016-12-01 17:54:34 +00:00
Vadim Pisarevsky
e623e710be Merge pull request #7597 from terfendail:ovx_threshold 2016-12-01 17:53:38 +00:00
Vadim Pisarevsky
32f48a8d9c Merge pull request #7631 from savuor:openvx_accumulate 2016-12-01 17:49:18 +00:00
Vadim Pisarevsky
8968318dfc Merge pull request #7668 from savuor:openvx_equalize_hist 2016-12-01 17:43:44 +00:00
Vitaly Tuzov
6d55e99291 Added OpenVX based processing to boxFilter 2016-11-30 11:27:25 +03:00
Li Peng
2ca5a7e862 more optimization for warpAffine and warpPerspective
Add new OpenCL kernels for bicubic interploation, it is 20% faster
than current warp image kernel with bicubic interploation.

Signed-off-by: Li Peng <peng.li@intel.com>
2016-11-30 15:43:41 +08:00
Vadim Pisarevsky
c47267ef7f Merge pull request #7538 from Tetragramm:CLAHEfix 2016-11-29 16:42:05 +00:00
Vadim Pisarevsky
57aaec1ee8 Merge pull request #7610 from terfendail:ovx_sobel 2016-11-29 16:40:10 +00:00
Rostislav Vasilikhin
0ac934d09a added OpenVX call to equalizeHist() function 2016-11-29 17:53:47 +03:00
Rostislav Vasilikhin
7c2734ff14 added OpenVX calls to accumulate(), accumulateSquare(), accumulateWeighted() 2016-11-29 17:53:35 +03:00
Vitaly Tuzov
0cd3788624 Added OpenVX based processing to threshold 2016-11-29 15:35:52 +03:00
Vitaly Tuzov
9200db778c Added OpenVX based processing to medianBlur 2016-11-29 15:32:07 +03:00
Vitaly Tuzov
e8f3469096 Added OpenVX based processing to Sobel 2016-11-29 15:29:00 +03:00
Alexander Alekhin
90b52cd9b8 Merge pull request #7726 from pengli:warp_image 2016-11-29 12:19:18 +00:00
Li Peng
b72d196753 optimization for warpAffine and warpPerspective
Add new ocl kernels for warpAffine and warpPerspective,
The average performance improvemnt is about 30%. The new
ocl kernels require CV_8UC1 format and support nearest
neighbor and bilinear interpolation.

Signed-off-by: Li Peng <peng.li@intel.com>
2016-11-29 14:55:58 +08:00
Alexander Alekhin
7dc673fd56 imgproc: fix findContours (submatrix input) 2016-11-25 18:25:26 +03:00
Alexander Alekhin
88ef8c996e Merge pull request #7709 from alalek:fix_java_tests 2016-11-24 16:15:56 +00:00
Alexander Alekhin
4fd00c1ae1 Merge pull request #7714 from onixie:master
Fix docs explaining the returnPoints argument of convexHull.
2016-11-23 17:44:05 +03:00
Rostislav Vasilikhin
7db43f9fff fixed wrong equivalence in YUV conversion (#7481)
* fixed wrong equivalence in YUV conversion

* fixed channel order from YVU to YUV
2016-11-23 17:39:18 +03:00
Vadim Pisarevsky
b8c875d4a1 Merge pull request #7707 from K-Shinotsuka:issue37 2016-11-23 14:15:02 +00:00
monoid911
b879126584 Fix docs explaining the returnPoints argument of convexHull. 2016-11-23 20:43:52 +09:00
Alexander Alekhin
8019498c6e java tests fixes 2016-11-23 13:53:00 +03:00
k-shinotsuka
284006e336 add NEON code for RGB2Luv_f. 2016-11-23 19:18:41 +09:00
Vadim Pisarevsky
c1ee798213 Merge pull request #7662 from K-Shinotsuka:issue34 2016-11-22 13:57:13 +00:00
Vadim Pisarevsky
af22b6c4a9 Merge pull request #7664 from K-Shinotsuka:issue35 2016-11-22 13:49:14 +00:00
Vadim Pisarevsky
b54bc2db1e Merge pull request #7665 from K-Shinotsuka:issue36 2016-11-22 13:44:42 +00:00
Pavel Vlasov
dfb9c574a4 IPP 2017 filter2D fix;
filter2D IPP runtime check;
2016-11-21 17:18:03 +03:00
Li Peng
6cb73356b1 laplacian ocl kernel optimization
This ocl kernel is 46%~171% faster than current laplacian 3x3
ocl kernel in the perf test, with image format "CV_8UC1".

Signed-off-by: Li Peng <peng.li@intel.com>
2016-11-17 12:01:02 +08:00
k-shinotsuka
cf5c400ecb add SSE code for RGB2HLS_f. 2016-11-16 00:46:13 +09:00
Alexander Alekhin
c93fb14dd2 Merge pull request #7653 from pengli:deriv 2016-11-14 13:40:04 +00:00
Juha Reunanen
5bb08bae28 Merge pull request #7464 from reunanen:test-7409-7458
Change contour test images to be very wide (#7464)

* Change contour test images to be very wide (#7409, #7458)

Unfortunately, slows down the tests.

* Decrease the number of contour test cases, in order to (at least partially) offset the test run duration increase caused by making the test images wider

* Don't test with very wide images on 32-bit architectures
2016-11-14 16:31:29 +03:00
Li Peng
8d4a7d3dcc sobel and scharr ocl kernel optimization
It improves 108%~230% performance in the perf test
with image format "CV_8UC1" and kernel size 3.

Signed-off-by: Li Peng <peng.li@intel.com>
2016-11-14 15:34:59 +08:00
k-shinotsuka
a909527a39 add SSE code for HLS2RGB_f. 2016-11-14 01:44:33 +09:00
k-shinotsuka
614ce7743e add SSE code for HSV2RGB_f. 2016-11-13 23:46:21 +09:00
Vadim Pisarevsky
4ebdf4938a Merge pull request #7634 from paroj:undistpt 2016-11-11 14:13:18 +00:00
Alexander Alekhin
b2e0873af1 Merge pull request #7629 from alalek:issue_7626 2016-11-10 16:35:08 +00:00
Vadim Pisarevsky
a2d6d96ef1 Merge pull request #7161 from terfendail:shortline_fix 2016-11-10 16:02:20 +00:00
Pavel Rojtberg
3609343acf undistortPoints: only consider distCoeffs if present
iters should be 0 if we have no distortion. Also skip tilt distortion in
that case.
Furthermore move variable declarations to usage sites.
2016-11-09 16:11:26 +01:00
Alexander Alekhin
17ffb28807 Merge pull request #7602 from mshabunin:fix-opencl-warnings 2016-11-09 12:35:00 +00:00
Alexander Alekhin
f1d93cb23b Merge pull request #7624 from pengli:gaussian_blur 2016-11-09 09:25:25 +00:00
Alexander Alekhin
183c75358b imgproc: fix trailingZeros for MSVS 2010 2016-11-08 16:48:41 +03:00
Pavel Vlasov
349d5ba012 --perf_instrument parameter now has int type and 0, 1, 2 modes (1 - simple trees, 2 - expanded trees for functions with same name but different calling address);
Maximum depth limit var was added to the instrumentation structure;

Trace names output console output fix: improper tree formatting could happen;
Output in case of error was added;

Custom regions improvements;

Improved timing and weight calculation for parallel regions; New TC (threads counter) value to indicate how many different threads accessed particular node;

parallel_for, warnings fixes and ReturnAddress code from Alexander Alekhin;
2016-11-08 10:18:05 +03:00
Li Peng
8f63f51e81 gaussian blur ocl kernel optimization
This ocl kernel is for 3x3 kernel size and CV_8UC1 format
It is 115% ~ 300% faster than current ocl path in perf test

python ./modules/ts/misc/run.py -t imgproc --gtest_filter=OCL_GaussianBlurFixture*

Signed-off-by: Li Peng <peng.li@intel.com>
2016-11-08 11:22:26 +08:00
Alexander Alekhin
442380bfac Merge pull request #7585 from pengli:morph_filter 2016-11-07 17:11:32 +00:00
mshabunin
3e28d51779 Fixed several OpenCL compiler warnings 2016-11-07 16:49:12 +03:00
Li Peng
35198b84a4 morph ocl kernel for erode and dilate filter
This kernel is for CV_8UC1 format and 3x3 kernel size,
It is about 33% ~ 55% faster than current ocl kernel with below perf test

python ./modules/ts/misc/run.py -t imgproc --gtest_filter=OCL_ErodeFixture*
python ./modules/ts/misc/run.py -t imgproc --gtest_filter=OCL_DilateFixture*

Also add accuracy test cases for this kernel, the test command is

./bin/opencv_test_imgproc --gtest_filter=OCL_Filter/MorphFilter3x3*

Signed-off-by: Li Peng <peng.li@intel.com>
2016-11-04 12:24:24 +08:00
Tetragramm
17df65e666 Fix the OpenCL portion to match the c++ code.
Fix an undiscovered bug in the c++ code.
2016-11-03 20:41:16 -05:00
Vadim Pisarevsky
3dc022ae84 Merge pull request #7423 from grahamfyffe:leading_edges 2016-11-03 11:20:43 +00:00
Vadim Pisarevsky
6fceb1dd59 Merge pull request #7601 from sovrasov:remap_big_img_assert 2016-11-02 14:17:04 +00:00
Vadim Pisarevsky
bebd49d91b Merge pull request #7467 from tomoaki0705:featureCheckSimdUniversal 2016-11-02 12:30:55 +00:00
Vladislav Sovrasov
af01267f23 Add assertion to prevent processing of large images in remap 2016-11-02 14:17:56 +03:00
Vadim Pisarevsky
8944875258 Merge pull request #7526 from alalek:fix_arm_builds 2016-11-02 10:49:43 +00:00
Vadim Pisarevsky
94d879737b Merge pull request #7582 from K-Shinotsuka:issue32 2016-11-02 10:48:29 +00:00
Vadim Pisarevsky
01f355dfaa Merge pull request #7583 from K-Shinotsuka:issue33 2016-11-02 10:47:33 +00:00
k-shinotsuka
a7db950b66 add SSE code for Lab2RGB_f. 2016-11-01 22:33:58 +09:00
abratchik
f978ee613e fix for #7510, #7511 and #7512 2016-10-31 11:07:56 +04:00
Alexander Alekhin
4c66772783 Merge pull request #7516 from sovrasov:find_contours_fix 2016-10-30 08:33:12 +00:00
k-shinotsuka
c1c7c7f83e add SSE code for Luv2RGB_f. 2016-10-30 14:50:18 +09:00
Vadim Pisarevsky
7b532cea89 Merge pull request #7540 from K-Shinotsuka:issue31 2016-10-29 21:28:25 +00:00
Vadim Pisarevsky
2b7866f21b Merge pull request #7503 from pengli:box_filter_v2 2016-10-29 21:20:06 +00:00
k-shinotsuka
992795d47d add SSE code for RGB2Luv_f. 2016-10-29 15:28:31 +09:00
Tomoaki Teshima
cba22349b7 add universal hardware support check function
* use hasSIMD128 rather than calling checkHardwareSupport
  * add SIMD check in spartialgradient.cpp
  * add SIMD check in stereosgbm.cpp
  * add SIMD check in canny.cpp
2016-10-29 13:24:31 +09:00
Vladislav Sovrasov
56c133d459 Disable redundant border initialization in findContours 2016-10-28 11:05:54 +03:00
Pavel Vlasov
f07525031b BORDER_ISOLATED support for Laplacian, boxFilter and morphology; 2016-10-27 09:53:19 +03:00
Li Peng
3607da9f6b ocl kernel performance optimization for box filter
The optimization is for CV_8UC1 format and 3x3 box filter,
it is 15%~87% faster than current ocl kernel with below perf test

./modules/ts/misc/run.py -t imgproc --gtest_filter=OCL_BlurFixture*

Also add test cases for this ocl kernel.

Signed-off-by: Li Peng <peng.li@intel.com>
2016-10-26 11:56:11 +08:00
Vladislav Sovrasov
34df4ae02a Add a regression test, fix documentation 2016-10-25 11:38:07 +03:00
Vladislav Sovrasov
1f4f50b9dc findContours: integrate workaroung to allow contours detection on image border 2016-10-25 11:38:07 +03:00
Vladislav Sovrasov
f5592fd21b Fix wrong default mask value in floodFill 2016-10-25 11:16:59 +03:00
Tetragramm
c6772a8f5d Fix CLAHE distribution.
Fix CLAHE for 16-bit images.
2016-10-21 19:54:42 -05:00
Alexander Alekhin
7a9ed39655 test: update HoughLines perf test 2016-10-20 16:54:35 +03:00
LukeZhu
ef47bcc88b Fix the problem: filterSmall.cl report error with double 2016-10-17 15:12:42 +08:00
Vitaly Tuzov
26c9889c6b Fix for incorrect line drawing beyond 32768 row or column 2016-10-14 18:37:59 +03:00
Vadim Pisarevsky
4acda3f609 Merge pull request #7428 from alalek:cmake_fix_compiler_flags_detection 2016-10-12 19:38:25 +00:00
Alexander Alekhin
994815fbd4 Merge pull request #7413 from tomoaki0705:featureUniversalThreshold 2016-10-12 10:01:37 +00:00
Juha Reunanen
0f387cda8f Merge pull request #7451 from reunanen:issue-7409
Fix findContours crash for very large images (#7451)

* Cast step to size_t in order to avoid integer overflow when processing very large images

* Change assert to CV_Assert
2016-10-12 10:34:51 +03:00
Tomoaki Teshima
ea6410d1e7 use universal intrinsic in threshold
* add performance test for 32F and 64F threshold
  * requires update of opencv_extra
2016-10-11 18:00:41 +09:00
Alexander Alekhin
218f7574f9 Merge pull request #7440 from mschoeneck:Prefer_OCL_befor_IPP_for_Sobel_and_Scharr 2016-10-10 10:45:27 +00:00
StevenPuttemans
947f32d2e0 add border replicate note 2016-10-10 09:55:13 +02:00
matze
d9f6a06773 Adding check for IPP if UMat and OpenCL is available in Sobel and Scharr. 2016-10-09 15:37:22 +02:00
Alexander Alekhin
5da8d65371 eliminate compiler warnings 2016-10-08 02:19:43 +03:00
Graham Fyffe
57be99ff18 Added getLeadingEdges function to subdivision2d 2016-10-06 18:01:34 -07:00
Vadim Pisarevsky
84699e0e18 Merge pull request #7399 from K-Shinotsuka:issue27 2016-10-06 13:31:06 +00:00
Vadim Pisarevsky
294bea11a5 Merge pull request #7401 from K-Shinotsuka:issue28 2016-10-06 13:30:31 +00:00
Vadim Pisarevsky
8ee459207e Merge pull request #7402 from K-Shinotsuka:issue29 2016-10-06 13:29:56 +00:00
Vadim Pisarevsky
285e6ad15b Merge pull request #7404 from K-Shinotsuka:issue30 2016-10-06 13:29:00 +00:00
k-shinotsuka
880ace2eb3 add simd code when dcn equals 4 at HSV2RGB_b(). 2016-10-06 00:06:02 +09:00
k-shinotsuka
db8b3252bf add simd code when scn equals 4 at RGB2HLS_b(). 2016-10-05 22:01:33 +09:00
k-shinotsuka
c1745539c4 add simd code when dcn equals 4 at HLS2RGB_b(). 2016-10-05 21:02:53 +09:00
Vadim Pisarevsky
42fbfb9be0 Merge pull request #7311 from fran6co:lsd 2016-10-05 11:27:43 +00:00
Vadim Pisarevsky
43b60f4617 Merge pull request #6961 from K-Shinotsuka:issue5 2016-10-05 11:23:35 +00:00
Vadim Pisarevsky
33ce36397c Merge pull request #7222 from mschoeneck:Improve_findContours_with_SSE2 2016-10-05 11:21:37 +00:00
Vadim Pisarevsky
2b01e316b3 Merge pull request #7392 from K-Shinotsuka:issue25 2016-10-05 11:19:43 +00:00
k-shinotsuka
a5f493a763 add simd code when scn equals 4 at Lab2RGB_b(). 2016-10-05 20:14:02 +09:00
k-shinotsuka
47c792ecc0 add simd code when scn equals 4 at RGB2Luv_b(). 2016-10-05 01:18:43 +09:00
Vadim Pisarevsky
eddd417d74 Merge pull request #7282 from alalek:fix_calculations 2016-10-04 15:05:42 +00:00
Vadim Pisarevsky
a3d44d523d Merge pull request #7214 from mshabunin:hal_integral 2016-10-04 12:26:58 +00:00
Vadim Pisarevsky
2e2ac54eca Merge pull request #7374 from catree:fix_hitmiss_doc_link 2016-10-04 12:15:58 +00:00
Vadim Pisarevsky
0ce3686a37 Merge pull request #7384 from K-Shinotsuka:issue24 2016-10-04 12:06:37 +00:00
Alexander Alekhin
cecc1857dd Merge pull request #7373 from tomoaki0705:featureCannyUniversalIntrinsic 2016-10-04 10:52:13 +00:00
Tomoaki Teshima
841ccccada use universal intrinsic in canny
* add v_abs for universal intrinsic
  * add test of v_abs in test_intrin
  * fix compile error on gcc
  * fix bool OR operation
2016-10-03 13:23:43 +09:00
k-shinotsuka
e310c3f9f4 add simd code when dcn equals 4 at Luv2RGB_b(). 2016-10-03 00:20:26 +09:00
Vadim Pisarevsky
39467d84bf Merge pull request #7353 from alalek:ocl_update_canny_test_threshold 2016-10-01 15:48:21 +00:00
Alexander Alekhin
1c18b1d245 Merge pull request #7370 from souch55:Fixxn 2016-10-01 10:44:56 +00:00
catree
2dd77f886a Fix dead link for hit or miss documentation. 2016-09-30 20:34:30 +02:00
sourin
a34fbf7bb1 Fixed identifiers warns 2016-09-30 15:16:29 +05:30
Maksim Shabunin
3d5c0f1faf HAL interface for cv::integral 2016-09-29 12:12:10 +03:00
Alexander Alekhin
696972bf8e ocl: update Canny test threshold
OpenCL Device:
- Intel(R) HD Graphics (OpenCL 2.0: r2.0.54425)
2016-09-28 13:38:02 +03:00
Alexander Alekhin
c66efd05fa imgproc: use target type for calculations
reduce scope of "i" variable
2016-09-22 15:14:59 +03:00
Alexander Alekhin
7366be696a imgproc: fix win32 build 2016-09-22 14:56:23 +03:00
Francisco Facioni
8283ddb52f LSD: Use a fixed size array instead of using std::vector 2016-09-22 12:39:49 +01:00
Francisco Facioni
de9c0d9926 LSD: Avoid re allocating the histogram for multiple calls of LineSegmentDetector::detect in ll_angle
This is useful when reusing the same instance of LineSegmentDetector for multiple images
2016-09-22 12:39:47 +01:00
Francisco Facioni
ef6b696446 LSD: Avoid pre allocating a big region, std::vector allocations is quite expensive 2016-09-22 12:39:45 +01:00
Francisco Facioni
a12207c3ad LSD: Avoid using pointers directly, image could be non continuous 2016-09-22 12:39:43 +01:00
Francisco Facioni
f5a0b226f2 LSD: Optimization, avoid converting the image to double 2016-09-22 12:39:37 +01:00
Alexander Alekhin
4ccde1330d Merge pull request #7323 from lupustr3:pvlasov/rgb_to_gray_array_fix 2016-09-22 09:52:16 +00:00
Alexander Alekhin
cde9d640fe Merge pull request #7309 from K-Shinotsuka:issue22 2016-09-21 14:46:53 +00:00
Pavel Vlasov
2073af2f05 RGB2Gray array size fix; 2016-09-21 17:46:51 +03:00
Alexander Alekhin
3f990accb0 Merge pull request #7306 from K-Shinotsuka:issue21 2016-09-21 12:47:33 +00:00
Alexander Alekhin
9b12bd915b Merge pull request #7305 from K-Shinotsuka:issue20 2016-09-21 12:47:15 +00:00
Alexander Alekhin
b2314c9ae5 Merge pull request #7304 from K-Shinotsuka:issue19 2016-09-21 12:46:30 +00:00
Alexander Alekhin
b43989bdaf Merge pull request #7303 from K-Shinotsuka:issue18 2016-09-21 12:45:16 +00:00
Alexander Alekhin
17f0c93b37 Merge pull request #7300 from K-Shinotsuka:issue17 2016-09-21 12:44:42 +00:00
Francisco Facioni
31bd84de12 LSD: Removes unused code 2016-09-19 15:29:30 +01:00
k-shinotsuka
0d85d2cc0a improve RGB2HLS_b() 2016-09-18 23:36:31 +09:00
k-shinotsuka
4f22f48e63 improve HSV2RGB_b() 2016-09-18 23:07:09 +09:00
k-shinotsuka
0fc187d7a3 improve HLS2RGB_b() 2016-09-18 15:46:00 +09:00
k-shinotsuka
1f8aa4f7d3 improve Lab2RGB_b() 2016-09-18 14:48:40 +09:00
k-shinotsuka
37be868679 improve RGB2Luv_b() 2016-09-18 11:08:57 +09:00
k-shinotsuka
4540260df9 improve Luv2RGB_b() 2016-09-17 19:42:48 +09:00
Vitaly Tuzov
48f132f35f Fix Sobel evaluation for image ROI without isolated border. 2016-09-16 16:08:37 +03:00
matze
975d2e4294 Enable built in counting trailing zeros function for Intel compiler and clang. 2016-09-14 18:20:47 +02:00
Vadim Pisarevsky
ab3814f9b9 Merge pull request #7191 from anirudt:docs_moments 2016-09-14 12:30:27 +00:00
matze
a865876c0f Added CV_UNUSED to not used variable when build without SSE2 support. 2016-09-13 19:32:37 +02:00
anirudt
2879eada25 docs: truncated commit msg 2016-09-13 16:14:05 +05:30
Vadim Pisarevsky
473dba1189 Merge pull request #7208 from terfendail:openvx_hal_impl 2016-09-13 10:15:12 +00:00
Vadim Pisarevsky
ca9183d567 Merge pull request #7034 from K-Shinotsuka:issue12 2016-09-13 10:05:46 +00:00
matze
aaa255465e Renamed haveSSE2 in haveSIMD. Conditional compilation for function header removed 2016-09-11 13:15:53 +02:00
Vadim Pisarevsky
a9ab869800 seriously improved performance of blur function, especially 3x3 and 5x5 cases (#7262)
* seriously improved performance of blur function, especially 3x3 and 5x5 cases

* trying to fix warnings and test failures

* replaced #if 0 with #if IPP_DISABLE_BLOCK
2016-09-09 23:31:02 +04:00
anirudt
06e0fb25e9 docs: adds doxygen @note for python in docs related to contour moments 2016-09-09 13:23:43 +05:30
Vitaly Tuzov
5ec47299e2 Fixed warpings, added border mode support to warps and filter. Added morphology HAL API functions implemented as immediate mode OpenVX calls. 2016-09-08 18:55:26 +03:00
Maksim Shabunin
c16f96cb5b Merge pull request #7221 from terfendail:sepfilter_vec_kernel 2016-09-06 20:41:28 +00:00
Maksim Shabunin
e2de96289b Merge pull request #7220 from paroj:imgproc_doxy 2016-09-06 14:33:17 +00:00
mschoeneck
9e61a28b2e Improve canny (#7227)
* Improve Canny by using _mm_movemask_epi8 to find next pixel magnitude greater than lower threshold. Added parallelized finalPass to Canny with variable gradients. Little changes in finalPass.

* Some things fixed
2016-09-05 13:51:36 +03:00
matze
fd6f54c895 Bug fixed in findEndContours and icvFindContoursInInterval adjusted. 2016-09-03 20:09:39 +02:00
matze
f6451c7ae6 Varaible names renamed. Macro definitions fixed. findEndContourPoint function fixed. findContoursInInterval adjusted. 2016-09-03 14:35:09 +02:00
matze
25cf33d5c8 Warning fixed by adding a cast to char 2016-09-02 21:09:25 +02:00
matze
0acd818efc Removed #elif defined(__INTEL_COMPILER) because it is disabled at the moment 2016-09-02 20:35:08 +02:00
matze
8af8c4d0aa Improves findContours using SSE _mm_movemask_epi8 to find next contour point. Cleaned up code a little bit 2016-09-02 20:09:13 +02:00
Pavel Rojtberg
cfcf8abbb6 doxygen: imgproc - underscores should not be escaped in texttt 2016-09-02 16:41:45 +02:00
Pavel Rojtberg
62cabb58a9 doxygen: undistortPoints - replace matlab code by latex forumlae 2016-09-02 16:41:45 +02:00