Most voted "opencv" questions
Opencv is a multiplatform and *open source* library for developing applications linked to Computer Vision.
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answers334
viewsReturn the index of a row with the min function in Python
I am trying to find the index of a numpy matrix (cut of a face detected in opencv) and draw a line where the sum of the pixels is the minimum value. I can’t return the index. Follow the code below…
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answer562
viewsError in subprocess.run( ) in Python 3.7.2
I’m using: Windows 10 Python 3.7.2 Shell (default IDLE) x64 I’m trying to follow the tutorial Learnopencv tutorial, I already downloaded the file class-descriptions-boxable.csv and…
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answers616
viewsProblem showing image in imshow
I have a function that opens an image and sums with a random matrix but the function cv2.addWeighted generates the following error even though the types of the two matrices are equal : Traceback…
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answer58
viewsIMPORT ERROR - No module named dlib
I installed dlib, opencv and Pillow through Anaconda, creating a enviroment, but when I will import dlib the following error happens: No module named dlib. I’ve already deleted the interpreters and…
python-3.x opencv dll artificial-intelligence pycharmasked 5 years, 6 months ago Marcos Paulo S. Rezende 351 -
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answers19
viewsImproving the efficiency of Camshift
I detect a previously trained object with the Haarcascade algorithm and pass the coordinates to Camshift at the beginning of the program to detect the region where the object in question is in the…
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answers95
viewsImage SVM classifier does not work
Hello, I’m with a program in Python that uses the library Dlib 19.10, the classifier uses an xml file to learn the images and then I run the following code that creates a file. svm for the…
python algorithm opencv image-processing artificial-intelligenceasked 5 years, 5 months ago Marcos Paulo S. Rezende 351 -
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answer1196
viewsCut part of an Image using a point list of a polygon
I have an image (see below) and a list of points that represent a given polygon of the image (e.g.. contours=[ [1430,2003], [1429,2003], [1428,2003], .... ]). I want to create a new image that has…
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answer500
viewsMultiple connections via rtsp using Opencv and Python
I recently made a basic Python script using the Opencv library for recognition using security cameras, but I realized that for some reason, I can’t open two or more connections on the same camera,…
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answer38
viewsOpencv build does not find include
I’m trying to compile a simple code just to test but when I compile with both g++ and Clang++ they say that the reference to the method was not found. I followed the steps of this official Opencv…
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answers75
viewsOpencv in kivy image detector ERROR camera hangs
Guys, I’m trying to run this code and it locks the camera and does nothing else. The idea of the code is to run the face detector inside the widgets + kivy using this library from kivy.uix.image…
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answer285
viewsHot color detection in Python image
I have a problem and I need your help. I have a series of thermographic images, which I need to detect the hot spot (shown in the bar to the right of the image) in the area where the analysis is…
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answers35
viewsProblems in transforming . py to . exe from my project to recognize images with opencv
I have a project of recognizing images using opencv, I separated it into 3 packages plus the code of the graphical interface in Tkinter that controls the activation. It works normally, but when I…
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answers41
viewsDoes Pyqt5 monitor events asynchronously on Windows and synchronously on Raspberry?
Context I’m developing a program that uses Opencv4 to identify some metal fasteners, the program is relatively simple and uses in short color search contour filters, in Windows so far everything…
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answer242
viewsHow to plot a graph when terminating a computer vision script on Raspberry pi?
I have a code using opencv Raspberry Pi and it is running a pattern recognition loop. In the end I close the script using "Ctrl + X" without any problem! I want to "stop" the graphical processing,…
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answer60
viewsCvrtrees function parameters::Train() - Opencv / C++
Hello! I need to use the function CvRTrees::train() Opencv, but I don’t quite understand the parameters used. To help, the site has no documentation on the parameters of this function. The…
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answer551
viewsCalculation of figures area
I may have something on the subject here, but I haven’t found it. I am new in the area and would like help to elaborate a C++ algorithm for detecting the area of a predetermined color in a figure.…
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answers297
viewsConnect D-link DCS-932L Camera with opencv
I’m trying to connect Opencv with a D-Link DCS-932L IP camera. IP, password, user and port are correct, but nothing works. I believe the error is in relation to the URL format. Below follows the…
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answer196
viewsProblems opening c++ software on another PC
I am developing a software in c++ using Visual Studio 2015, and I am using two external libraries, OPENCV and Flycapture2. I developed the software and it runs normally on my computer, but at the…
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answers107
viewsWhat is the best way to use projection histograms as characteristics in classifiers or Nns without using a resize on the image
I’m doing some work for digit recognition on digital displays and I’m looking to use projection histograms as characteristics for some classifier, however the images are all of different sizes…
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answer245
viewsHow to adjust focus using Opencv and Python?
Hello. I’m building a robot that moves through acquired images. However, when it is in motion, it gets lost due to the image being out of focus. I ask if there is any configuration within Opencv…
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answer73
viewsProblems with Opencv(python3 and ROS)
i am using ROS for a project in college, but when I try to use python 3 to call opencv, this problem occurs "Import: /opt/Ros/Kinetic/lib/python2.7/dist-Packages/cv2.so: Undefined Symbol:…
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answer34
viewsFunction Circle, how to send the center parameter?
I am sending the center parameter given by (2953,1999) as shown below: circle(imgOr,(2953,1999),224,Scalar(255,0,0)); But make a mistake: could not Convert (0,1999) from 'int' to 'cv::Point'…
opencvasked 6 years, 9 months ago Daniel Santos 35 -
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answers47
viewsCall error of a Python application (+Opencv) in Visual Studio 17 (C#)
I’m trying to make a "control panel" that each button will call a Python application(+Opencv) but when I run it through the Pycharm IDE, or straight from the folder, it runs perfectly, but when I…
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answers46
viewsheap corruption compiling an opencv project
void trackFilteredObject(int &x, int &y, Mat threshold, Mat &cameraFeed) { Mat temp; threshold.copyTo(temp); //these two vectors needed for output of findContours vector<…
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answers298
viewsError Indefinite Symbol Reference
Good Morning I am studying the Opencv library for computer vision on Ubuntu 14.04 I am using Eclipse Mars.2 programming in c++. The following error appears: ./image. o: indefinite reference to…
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answer338
viewsPython Opencv - Error using drawing function
I’ve been able to run this code before, but now it doesn’t work. It needs to draw a square on the video screen. Error: Traceback (Most recent call last): File…
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answer187
viewshow do I detect on which side is the object if I trace a line the medium
My friends, I’m discovering computer vision. I’m programmed in python and wanted to know how I do to identify in which position the object is in relation to a line drawn in the middle of the screen.…
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answer548
viewsIndexerror: list index out of range Python
I’m getting the following error: IndexError: list index out of range My code: conts = conts[0] if imutils.is_cv2() else conts[1] How can I correct this mistake? Complete code…
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answers15
viewsIs it possible to run a Body Cascade inside a non-slagging sub-area?
after studying a little and the help of well-oriented people here understood that Opencv manipulates images (an array) that will always be rectangular. Therefore, an ROI will never be polygonal. I…
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answer207
viewsKanade Lucas Tomasi (KLT) optical flow algorithm in Python
Hello. I searched all over the Internet and couldn’t find. Someone has an alternative to perform feature extraction on images with the python Kanade Lucas Tomasi (KLT) algorithm?
python opencv image-processing artificial-intelligence computer-scienceasked 5 years, 11 months ago FabianoF 55 -
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answer112
viewsCommand that replaces Team.Leep?
I am making a program that detects colors and shapes of objects with a camera, when being recognized the format and the color configured, the program makes the control of the GPIOS in which I…
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answers77
viewsError while running Android application with Opencv
I am trying to open my application on my Smartphone (Motorola G4 Play), but I am not successful. The following error is shown to me: E/art: No implementation found for void…
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answer2905
viewsSegment image and highlight object border using python
I’m testing some algorithms to improve the image quality that my hardware is getting. I have in the image a pick and I would like to highlight the object contained in it. I used the code below to…
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answer994
viewsIntelbrass cameras with python
I wonder if it is possible to take images of an intelbrass camera through ip by python, I searched a lot and found nothing, the code that came closest was this one: import cv2 cap =…
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answer37
viewsopencv in python
I need to make an algorithm that reads the color code and opens a window with the color. I know I need to use the library cv, but I don’t know how you do it and I can’t find anything like it on the…
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answers79
viewsCommand imread() and iteration
I’d like to make a loop with that command: imagem = cv2.imread("imagens/0.jpg",0) imagem = cv2.imread("imagens/1.jpg",0) imagem = cv2.imread("imagens/2.jpg",0) imagem = cv2.imread("imagens/3.jpg",0)…
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answer641
viewsHow to show image in Opencv?
I would like to take a part of an image play it in an array pass some kind of filter on it manually( without using the Opencv functions) and show the result in a window for the user. For that I want…
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answer239
viewsPython2.7 with Opencv 3.3.0 - Videocapture problem
I’m running Opencv 3.3.0. with Python 2.7 on a Windows 7 Professional x64 machine, and when I run the code below, falls in the prints "Something went wrong" and "Finished ..." import cv2 capture =…
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answer397
viewscv2.error: Opencv(4.1.0)
Code below: import cv2 imagemCarregada = cv2.imread("exemplo.jpg", 0) cv2.imshow("imagem", imagemCarregada) cv2.waitKey(0) cv2.destroyAllWindows() Error presented:…
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answer51
viewsopenCV - Differentiate RGB and P&B photos into a directory
Hello, Good morning. It has a directory (linux) with thousands of photos, and I need to separate color from black and white. I created the algorithm to scan all the files and move them to a specific…
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answers246
viewsSmile detection using opencv on android
Hello, I’m having difficulties to detect smiles using opencv on android. I can make the detection of faces and eyes very well using Aar Cascade but only the detection of smiles is not working using…
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answer40
viewsOpen.CV Error Save File
Good morning guys, I have the following code: var faceImage = new Image<Gray, byte>(new Bitmap(bm)); imagensFace[i] = faceImage.Resize(100, 100, Inter.Cubic); faceLabels[i] = todasFaces[i].ID;…
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answers110
viewsHow to save and finish python code?
I’m using a camera to capture video, and save the video. I’m trying to save and finish the code with a command in the IDLE(python) but I’m not getting it. Actualement to finish and save the program…
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answer73
viewsHow to use open cv with nodejs in production environment
I have an application developed in nodejs in which I use the opencv4nodejs which allows you to use the opencv library in nodejs. The application is ready on local server, but I have no idea how to…
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answers233
viewsObject Tracking in Opencv (Right or Wrong)
Ola Personal I am in a project of visual computing here of the company and I wanted to know of the most experienced in the subject if I am doing the right to train an object. I read a lot and…
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answer122
viewsOpencv c ++ how to display a text (letter) on the webcam in c++?
I’m using, open source, sorry, I’m beginner, I want to change it on if and else: else if (!thumbIsOpen && !firstFingerIsOpen && !secondFingerIsOpen && !thirdFingerIsOpen…
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answer99
viewsI’m doing a test with opencv and python but the code below does not return anything.... Some poedria help me see if there is any error?
import numpy as np import cv2 cap = cv2.VideoCapture('peopleCounter.avi') #Open video file while(cap.isOpened()): ret, frame = cap.read() #read a frame try: cv2.imshow('Frame',frame) frame2 = frame…
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answer137
viewsSyntax error in if and Elif systems
while True: ret,img=cam.read(); gray=cv2.cvtColor(img,cv2.COLOR_BGR2GRAY) faces=faceDetect.detectMultiScale(gray,1.3,5); for (x,y,w,h) in faces: cv2.rectangle(img,(x,y),(x+w,y+h),(0,0,255),2) id,…
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answer54
viewsFunction to increment the file name - python(opencv)
i have this code that saves me a video every time I run the program with the name video0. out = cv2.VideoWriter(video0.avi', fourcc, fps, (int(width), int(height))) I wanted him now every time I ran…
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answers806
viewsHow to use cv2.imread() with an image type object instead of "image path"?
I wonder if there’s any way to do something like this: import cv2, pyautogui screenshot = pyautogui.screenshot() cv2.imread(screenshot, 0) Instead: import cv2, pyautogui screenshot =…