# \#ximgproc **URL:** https://forum.opencv.org/tag/ximgproc/236.md [Latest](https://forum.opencv.org/latest.md) · [Categories](https://forum.opencv.org/categories.md) · [Tags](https://forum.opencv.org/tags.md) --- ## [How to understand distPointLine function in FastLineDetectorImpl](https://forum.opencv.org/t/how-to-understand-distpointline-function-in-fastlinedetectorimpl/19013)
**Author:** [@cvInterest](https://forum.opencv.org/u/cvInterest)\ **Replies:** 0\ **Last updated:** [October 19, 2024, 4:03am UTC](https://forum.opencv.org/t/how-to-understand-distpointline-function-in-fastlinedetectorimpl/19013 "2024-10-19T04:03:23Z")
this function get the distance from point to line , i can not understand the calculate method it use. double FastLineDetectorImpl::distPointLine(const Mat& p, Mat& l) { double x = l.at\(0,0); double y = l… --- ## [\`cv::ximgproc::thinning\` is too slow](https://forum.opencv.org/t/cv-thinning-is-too-slow/16696)
**Author:** [@Peiqi.Liu](https://forum.opencv.org/u/Peiqi.Liu)\ **Replies:** 0\ **Last updated:** [March 5, 2024, 9:21am UTC](https://forum.opencv.org/t/cv-thinning-is-too-slow/16696 "2024-03-05T09:21:41Z")
cv::ximgproc::thinning is too slow. Even though the thinningIteration function can use parallel processing, it is still much slower compared to Halcon, with 2000ms (OpenCV) vs 3ms (Halcon)! namespace cv { namespace ximg… --- ## [Opencv2.framework for iOS is missing +contrib](https://forum.opencv.org/t/opencv2-framework-for-ios-is-missing-contrib/16584)
**Author:** [@wolf359](https://forum.opencv.org/u/wolf359)\ **Replies:** 1\ **Last updated:** [February 24, 2024, 7:54pm UTC](https://forum.opencv.org/t/opencv2-framework-for-ios-is-missing-contrib/16584 "2024-02-24T19:54:17Z")
I’m developing an iPhone app that requires ximgproc, which is in the +contrib branch. Unfortunately, opencv2.framework for iOS seems to be built without +contrib. Is there a way to add it, or to request OpenCV to includ… --- ## [A fast ellipse detection method in OpenCV 4.7.0](https://forum.opencv.org/t/a-fast-ellipse-detection-method-in-opencv-4-7-0/11586)
**Author:** [@sirius](https://forum.opencv.org/u/sirius)\ **Replies:** 1\ **Last updated:** [January 12, 2023, 4:46am UTC](https://forum.opencv.org/t/a-fast-ellipse-detection-method-in-opencv-4-7-0/11586 "2023-01-12T04:46:29Z")
This function is able to detection ellipse or elliptic object in images, and directly return the parameters of ellipse. The method is based on Qi Jia, Xin Fan, Zhongxuan Luo, Lianbo Song, and Tie Qiu. A fast ellipse … --- ## [How do I find the contours of a letter](https://forum.opencv.org/t/how-do-i-find-the-contours-of-a-letter/11125)
**Author:** [@stonechen](https://forum.opencv.org/u/stonechen)\ **Replies:** 9\ **Last updated:** [November 27, 2022, 9:46pm UTC](https://forum.opencv.org/t/how-do-i-find-the-contours-of-a-letter/11125 "2022-11-27T21:46:07Z")
I used the findcontours method but it does not work as expected. What I want is the sketched version of the letter “v” from the original image. This is the original image of letter “v” After using findcontours, code… --- ## [Segmentation fault when using cv2.ximgproc.ContourFitting](https://forum.opencv.org/t/segmentation-fault-when-using-cv2-ximgproc-contourfitting/11001)
**Author:** [@tosabe](https://forum.opencv.org/u/tosabe)\ **Replies:** 7\ **Last updated:** [November 17, 2022, 9:45am UTC](https://forum.opencv.org/t/segmentation-fault-when-using-cv2-ximgproc-contourfitting/11001 "2022-11-17T09:45:40Z")
I’d like to use cv2.ximgproc.ContourFitting for contours which is found by cv2.findContours but I can’t use it because it generate segmentation fault. The error message is only zsh: segmentation fault (core dumped) pyth… --- ## [Same code running in Linux much slower than in Windows](https://forum.opencv.org/t/same-code-running-in-linux-much-slower-than-in-windows/8862)
**Author:** [@lzlu123](https://forum.opencv.org/u/lzlu123)\ **Replies:** 0\ **Last updated:** [May 20, 2022, 6:35pm UTC](https://forum.opencv.org/t/same-code-running-in-linux-much-slower-than-in-windows/8862 "2022-05-20T18:35:15Z")
Hi, I have a dual boot PC with Windows 10 and ubuntu 20.04 on same SSD. I build OpenCV 4.5.5 with contrib model in both platforms using same configuration. My aim is to compare the performance of c++ program using Op… --- ## [Train an EdgeBoxes Model](https://forum.opencv.org/t/train-an-edgeboxes-model/8743)
**Author:** [@Orjwan\_Zaafarani](https://forum.opencv.org/u/Orjwan_Zaafarani)\ **Replies:** 1\ **Last updated:** [May 12, 2022, 6:25am UTC](https://forum.opencv.org/t/train-an-edgeboxes-model/8743 "2022-05-12T06:25:33Z")
I recently viewed the EdgeBoxes demo at opencv\_contrib/edgeboxes\_demo.py at 96ea9a0d8a2dee4ec97ebdec8f79f3c8a24de3b0 · opencv/opencv\_contrib · GitHub . However, I can’t find an API to train an EdgeBoxes model in Python. … --- ## [How to calculate width of each worm in the image?](https://forum.opencv.org/t/how-to-calculate-width-of-each-worm-in-the-image/999)
**Author:** [@amaze](https://forum.opencv.org/u/amaze)\ **Replies:** 6\ **Last updated:** [April 8, 2022, 11:15am UTC](https://forum.opencv.org/t/how-to-calculate-width-of-each-worm-in-the-image/999 "2022-04-08T11:15:54Z")
Code \_, binary = cv2.threshold(gray, 225, 255, cv2.THRESH\_BINARY\_INV) #find the contours from the thresholded image contours, hierarchy = cv2.findContours(binary, cv2.RETR\_EXTERNAL, cv2.CHAIN\_APPROX\_SIMPLE)\[-2:\] #Calc… --- ## [About using edge boxes](https://forum.opencv.org/t/about-using-edge-boxes/7890)
**Author:** [@MakeItGreatAgain](https://forum.opencv.org/u/MakeItGreatAgain)\ **Replies:** 1\ **Last updated:** [March 11, 2022, 7:39am UTC](https://forum.opencv.org/t/about-using-edge-boxes/7890 "2022-03-11T07:39:48Z")
Hello, The question is about using Edgeboxes. In the sample of Edgeboxes, a model is required as the input to create at the very beginning, see line below. cv::Ptrcv::ximgproc::StructuredEdgeDetection pDollar = cv::xi… --- ## [An error occurred using opencv SLIC c++](https://forum.opencv.org/t/an-error-occurred-using-opencv-slic-c/5926)
**Author:** [@ramge132](https://forum.opencv.org/u/ramge132)\ **Replies:** 1\ **Last updated:** [October 28, 2021, 2:09pm UTC](https://forum.opencv.org/t/an-error-occurred-using-opencv-slic-c/5926 "2021-10-28T14:09:42Z")
the original source: I’m using VisualStudio17, 19 the error message is: |error|LNK2019|struct cv::Ptr \_\_cdecl cv::ximgproc::createSuperpixelSLIC(class cv::debug\_build\_guard::\_InputArray const &,int,int,float) (?cr… --- ## [Set each pixel in the output image to the mean RGB color of the superpixel region](https://forum.opencv.org/t/set-each-pixel-in-the-output-image-to-the-mean-rgb-color-of-the-superpixel-region/4817)
**Author:** [@tetengious](https://forum.opencv.org/u/tetengious)\ **Replies:** 4\ **Last updated:** [August 17, 2021, 5:16pm UTC](https://forum.opencv.org/t/set-each-pixel-in-the-output-image-to-the-mean-rgb-color-of-the-superpixel-region/4817 "2021-08-17T17:16:28Z")
I’m working on image segmentations where need to calculate image superpixels. I have calculated, and displayed the image superpixel successfully but unable to color each pixel in the output image to the mean RGB color ju… --- ## [How to find the rotated angle of object?](https://forum.opencv.org/t/how-to-find-the-rotated-angle-of-object/3075)
**Author:** [@MohamedEmara](https://forum.opencv.org/u/MohamedEmara)\ **Replies:** 11\ **Last updated:** [May 5, 2021, 12:05pm UTC](https://forum.opencv.org/t/how-to-find-the-rotated-angle-of-object/3075 "2021-05-05T12:05:53Z")
@laurent.berger Thanks for the code! I am currently using it for one of my projects and was wondering in the equations you supplied at the end, why is the boundary for the second equation p=-N/2 to N/2-1. It is my unders… --- ## [How to apply feature matching method to enhance Stereo Disparity Map result](https://forum.opencv.org/t/how-to-apply-feature-matching-method-to-enhance-stereo-disparity-map-result/2812)
**Author:** [@laub1199](https://forum.opencv.org/u/laub1199)\ **Replies:** 4\ **Last updated:** [April 17, 2021, 5:45pm UTC](https://forum.opencv.org/t/how-to-apply-feature-matching-method-to-enhance-stereo-disparity-map-result/2812 "2021-04-17T17:45:13Z")
Recently I’m using the Middlebury Stereo Datasets 2005 for generating the disparity map. Only the dataset Art, Dolls and Reindeer will be used. The requirement is to generate the disparity map with only view1.png and vie… --- ## [OutofMemoryError when using large image in StructuredEdgeDetection](https://forum.opencv.org/t/outofmemoryerror-when-using-large-image-in-structurededgedetection/2530)
**Author:** [@satheesh\_kumar](https://forum.opencv.org/u/satheesh_kumar)\ **Replies:** 1\ **Last updated:** [April 1, 2021, 10:59am UTC](https://forum.opencv.org/t/outofmemoryerror-when-using-large-image-in-structurededgedetection/2530 "2021-04-01T10:59:09Z")
I’m trying to use the detectEdges function from org.opencv.ximgproc.StructuredEdgeDetection class . This is the sample code I’m using StructuredEdgeDetection pDollar = createStructuredEdgeDetection(file.toString()); p… --- ## [Getting clean lines from a smudged image](https://forum.opencv.org/t/getting-clean-lines-from-a-smudged-image/2424)
**Author:** [@c\_dottel](https://forum.opencv.org/u/c_dottel)\ **Replies:** 2\ **Last updated:** [March 28, 2021, 8:50pm UTC](https://forum.opencv.org/t/getting-clean-lines-from-a-smudged-image/2424 "2021-03-28T20:50:23Z")
I would like to turn the blurry lines into sharp thin lines if possible. Get rid of all gray pixels and make them all black or white. But I have been having trouble doing this. Threshold doesnt get rid of all of the g…