16,624 questions with no answers
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Error throwing while building opencv with gstreamer support
I am trying to build opencv from source to enable GStreamer support. I have followed this instructions here, but an error occurred. More specifically, the error occurred in this step:
make -j$(nproc)
...
- 5,743
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58
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OpenCV - LOG_LEVEL_SILENT doesn't work when reading image from file using imread
I would like to silence OpenCV errors that occur while attempting to read an image that it does not support, example HEIC. I have tried setting the OPENCV_LOG_LEVEL environment variable as well as the ...
- 35.8k
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25
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opencv.js in node throws abort(ReferenceError: document is not defined)
I want to use opencv in node. Found @techstark/opencv-js and looks promising, but I cannot run even a simple example.
I've installed the examples from https://github.com/TechStark/opencv-js-examples. ...
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54
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Green video output when streaming to RTSPtoWeb using GStreamer
I’m trying to make a script in python that restream an RTSP feed that has been processed in OpenCV (where I overlay the current date and time on each frame).
After processing, I use GStreamer to ...
- 16.4k
-1
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63
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Python OpenCV LBPHFaceRecognizer "Unknown C++ exception from OpenCV code"
Trying to build a mini face recognition project from a set of pictures in a folder
When trying to use LBPH algorithm to do so using:
recognizer = cv.face.LBPHFaceRecognizer()
I get:
"Unknown C++...
- 35.8k
3
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573
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OpenCV 3 gives opposite class labels in Gaussian Mixture Model
I'm using OpenCV 3.1.0 to fit a Gaussian Mixture Model to two-class data using EM. The samples are labeled, so I provide the class means and covariances during training by using EM::trainE. When I ...
- 16.4k
3
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1k
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OpenCV stitcher fails to stitch undistorted images
I am trying to stitch a panorama using mobile phone camera with an attachable 170 degree wide angle lens. The resulting photo is distorted (fisheye). I understand that to stitch these photos using ...
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7
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225
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Why should images not be cylindrically warped before homography estimation in an image stitching pipeline?
I am working on an image stitching pipeline for video feeds but am still missing some key insights. I am for example using Szeliski's Image Alignment and Stitching: A Tutorial for a general ...
- 2,054
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53
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cuda commands from python in opencv fail
I've compiled opencv with cuda support and am trying to use some cuda functions - to that end I'm trying the following test:
import cv2
if cv2.cuda.getCudaEnabledDeviceCount() > 0:
print("...
- 72.7k
2
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answers
893
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Are there in OpenCV any Optical-Flow algorithms which rotate and/or scale-invariant?
In OpenCV we can use features to detection objects, and there are features which are all translation-invariant and also:
Which scale-invariant and rotate-invariant: SIFT, SURF, BRISK, FREAK, STAR
And ...
- 16.4k
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93
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OpenCV edge detection on PNG image with Canny
I am new to OpenCV with linux. I am currently working on tube rack's bounding detection. But as you can see, one of rack's bounding is blurred by shadow.
Despite having used histogram equalization to ...
- 35.8k
1
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69
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How can I have intellisense in VS Code for opencv.js
I want to have intellisense for opencv.js inside VS Code when I call it from a JavaScript file, but when I use import "path/opencv.js" or import cv from "path/opencv.js", I can't ...
- 19
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52
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compiling OpenCV on linux generate error related to LibCap
I am trying to compile a simple application that uses OpenCV in Linux:
The CMAkeFile.txt is as follow:
cmake_minimum_required(VERSION 3.29)
# Enable vcpkg manifest mode
if(DEFINED ENV{VCPKG_ROOT})
...
- 18.4k
1
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88
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How can I optimize a Python RTSP → YOLOv8 face-recognition → WebSocket pipeline to handle 6–8 cameras without lag/stutter?
What i am Trying to do?
I want to access the ip cameras and add a face recognition model to the live feed and display it to the web browser frontend for the ease of access this is the main concern, ...
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37
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Getting "ImportError: DLL load failed" after building an .exe in Python
I use Python 3.10 and OpenCV, building from sources with CUDA enabled and it worked. Then I try to build the .exe using Pyinstaller this also worked.
Problem:
When I try to run the EXE file, the ...
- 16.2k
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150
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LeRobot SO101 Camera getting ConnectionError when trying to connect
When I try to detect my camera using python -m lerobot.find_cameras opencv I get a ton of errors like global obsensor_uvc_stream_channel.cpp:158 cv::obsensor::getStreamChannelGroup Camera index out of ...
- 16.4k
0
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289
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Issue with imread. Strange float values
I'm trying to simple load an image (TIFF) and display a pixel value.
If I open the image using ImageJ the values are 32-bit float. But opening the same image using opencv I get really strange float ...
- 42.5k
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75
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Tensorflow speed of tf.nn.conv2D used instead of opencv GaussianBlur
I'm trying to move some computer vision tasks to tensorflow. The most intensive ops are convolutions, like GaussianBlur. The timings I get using timeit suggest that the GPU equivalent is >10 x ...
- 16.4k
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115
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Drawing out roof faces from satellite images with OpenCV
I am new to OpenCV and I am trying to make this output from that satellite image :
But I am running into a couple issues. I first thought about using a hough transform. But it started drawing lines ...
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3
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0
answers
2k
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Wave2Lip usage and performance
The actual Question:
Currently opencv is used to write video frames in a single file. Can you append the audio as well directly or is there some other way so you can create small video snippets which ...
- 1
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75
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How to implement the multiplicative extended kalman filter in opencv aruco application?
I've been looking to find a way of removing jitter from a project involving tracking two aruco marker boards. The camera is static and I have two marker boards moving with respect to one another. I ...
- 145
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307
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How to use hog detector to know if a preselected ROI is a person?
I want to use hog detector in order to know if a ROI is a person or not, I already coded a filtering technique allowing me to select ROIs that can contain a person.
for instance this is what I'm doing:...
- 16.4k
1
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1k
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OpenCV with Nvidia VPI (Vision Programming Interface), core dumped
I'm playing around with Vision Programming Interface (VPI) and trying to bend images. I came across this Lens Distortion Correction example (https://docs.nvidia.com/vpi/algo_ldc.html) and added some ...
- 16.4k
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How to install OpenCV for Visual Studio Code & Python?
My python version = 3.10.0.
My Visual Studio code version = 1.61.0
I also tried downloading OpenCV
(https://sourceforge.net/projects/opencvlibrary/files/4.5.4/opencv-4.5.4-vc14_vc15.exe/download)
and ...
CommunityBot
- 1
1
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0
answers
83
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OpenCV Java UnsatisfiedLinkError in IntelliJ with nonfree modules after compiling from source
I'm trying to use OpenCV's nonfree functionalities (like SIFT/SURF) in Java by compiling from source, but I'm encountering a DLL loading error in IntelliJ.
Here's my setup:
I'm using windows 11 24h2
...
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