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Compiling c++ code give an error "‘nameWindow’ was not declared in this scope"

I have a cpp code like below. #include #include #include using namespace std; using namespace cv; int main(int argc, const char *argv[]) { Mat img(480,640,CV_8UC3,Scalar(255,0,0)); if(img.empty()) {...

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OpenCV4: what is the order for linking static libs on centos 6

1.Building opencv4: cmake .. -DCMAKE_INSTALL_PREFIX=/home/wwd/software/opencv_4.1.0_build/ -DOPENCV_EXTRA_MODULES_PATH=/home/wwd/software/opencv_contrib-4.1.0/modules/ -DBUILD_SHARED_LIBS=OFF...

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cv::ml::rtrees oob error

Hi I'm using cv::ml::rtrees and am looking to access the out-of-bag error. Is there a way to access this in code (i.e. access some variable or call a getter that provides this value)? I know that this...

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cv::ml::rtrees oob error bug???

The way cv::ml::rtrees seems to calculate the oob error is as follows: 1. For loop iterates through the all the trees 2. For each tree: i. oob error is set to 0.0 ii. oob error is properly calculate...

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Mat ctor produces heap error?!?

I have made a c++ wxWidgets minimal example, unfortunately it is not possible to post it here directly, the format gets distorted and one can only attach images, so here it is:...

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undefined reference linker error opencv 3.1.0

I am using opencv 3.1.0 with DevC++ 5.11. I am getting the error : **undefined reference to `cv::Mat::copyTo(cv::_OutputArray const&, cv::_InputArray const&) const**' similarly for a large...

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Opencv 3.4.8 + Opencv contrib 3.4.8 + mingw32-make + ERROR while...

I'm working on compiling opencv with contrib on Win10. I followed the steps in [README.md]((https://github.com/opencv/opencv_contrib/blob/master/README.md)) on github. Things went well before the...

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TypeError: 'NoneType' object is not iterable

Hello world, I am trying to activate a github code that uses OpenCV, and I got an error of a NoneType, Please I will appreciate any help !!!! github link:...

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I am getting Segmentation fault (core dumped)

I am running ubuntu, python and trying to use AKAZE features on my camera. here is my code #!/usr/bin/python from __future__ import print_function import roslib import sys import rospy import cv2 from...

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LNK 1104 Visual Studio 2019 Error

Hi, Good morning I have this error in Visual Studio 2019 and I dont know how to solve, I was following this step from this website https://medium.com/@subwaymatch/opencv-410-with-vs-2019-3d0bc0c81d96...

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error: (-215:Assertion failed) !_src.empty() in function 'cvtColor'

Tengo el siguiente problema [image description](/upfiles/1582943083243196.png) Como lo puedo solucionar?

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Residual error from fundamental matrix

Hi guys, as in the previous topics I made I'm still working on self calibration stuff. I'm generating the data for the evaluation but I end out with some strange error computing the residual error as...

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Get an error when trying to install openCV. I don't understand the fix.

I am trying to install openCV using the instructions here. https://medium.com/@sourabhjigjinni/install-opencv-4-0-0-for-c-windows-7-10-code-blocks-tdm-gcc-64-dff65addf162 I get the error .... "error:...

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Error 'module' object has no attribute 'TrackerMIL_create'

OpenCV 3.4 Python 2.7 My code: import cv2 import numpy as np from datetime import datetime import time now = datetime.now() i=0 cap= cv2.VideoCapture(0); fourcc = cv2.VideoWriter_fourcc(*'XVID') out=...

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Python openCV drawing functions does not work?!

Hi, today I tried to draw a line in a window, this is the code I used. import numpy as np import cv2 # Create a black image img = np.zeros((512,512,3), np.uint8) # Draw a diagonal blue line with...

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fatal error: opencv2/aruco.hpp: No such file or directory

Hello, I installed Opencv and it worked just fine when I was working on QR Codes but now that i'm trying to use Aruco Markers I get this error. Is there something I'm missing? My OpenCV version is the...

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error adding symbols: File format not recognized

Hello i tried to build opencv via cmake but at 100% i get an error i dont understand. Could somebody pls help me.## Heading Here is the cmd: [ 95%] Building CXX object...

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cv::dilate Is it wanted behavior?

I create a short example of(in my opinion) bad behavior of dilate cv::Mat input(cv::Size(14, 14), CV_8U, cv::Scalar(0)); input.colRange(10, 14) = cv::Scalar(255); cv::line(input, cv::Point(1, 3),...

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error in findHomography with RANSAC

hi i wrote this codes for estimating Transformation Function between an 2d Image vs 3d Image as: src_pts = np.float32([kp1[m.queryIdx].pt for m in matches]).reshape(-1, 1, 2) dst_pts =...

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Error 6586736 in opencv.js

I use opencv.js and sometimes get an error 6586736. What does it mean?

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unspecified error & Process finished with exit code 0

hi I have written these codes about Image Processing: homography, mask = cv2.findHomography(src_pts, dst_pts, cv2.RANSAC, 5.0) pts = np.float32([[0, 0], [0, h - 1], [w - 1, h - 1], [w - 1,...

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OpenCV for Android will not compile

I'm having trouble getting OpenCV to compile with the Android toolchain. I can compile opencv for Linux just fine with or without contribs, but when I attempt to compile using the android toolchain,...

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FileNotFoundError: [Errno 2] No such file or directory:...

hi i used Pywavefront Module for importing OBJ files as: import pywavefront fox = pywavefront.Wavefront('fox.obj', collect_faces=False) but pycharm gave this error: **FileNotFoundError: [Errno 2] No...

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Poor Rectification Results After Good(?) Intrinsic/Extrinsic Parameter...

**Problem**: I have been trying to calibrate 4 cameras to use for 3D reconstruction in our lab but my results so far aren't great. **Physical Setup Details**: The cameras are mounted to the ceiling of...

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peculiar docker problem

Hi there, I am seeing some strange issues when using opencv (opencv-python==4.3.0.36) in a docker container. First the base image is python:3-slim I have a very simple python file that does something...

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Error compiling project with CMAKE

Hello, I want to compile my opencv project using cmake. Here is my CMakeLists.txt file cmake_minimum_required(VERSION 2.8) project( opencv_test ) set(OpenCV_DIR "C:/opencv/build/") find_package(OpenCV...

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malloc: can't allocate region at import cv2

Hello, I am running python3.9.0 and after installing cv I get the following error: It looks like it's trying to allocate memory size = 18446744071760121856 ? Please help. Thank you. nick$ python...

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Compile error: fatal error: opencv2/dnn/dnn.hpp: No such file or directory

I get the error message when trying to build my application, I have installed the opencv_contrib, I can use it from python, e.g. cv2.dnn, but when I try to build a simple c++ application I get this...

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c++ heap error without using the library?!

Hi everyone, I get this long list of heap errors without even using any opencv function, appearantly only by linking to the dll?!> Detected memory leaks! Dumping objects -> {7014} normal block at...

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heap errors without using anything from the lib

Hi everyone, I get this long list of heap errors without even using any opencv function, appearantly only by linking to the dll?! I leave out the middle part so the list does not get too long here:...

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