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Questions tagged [opencv3.3]

Use this tag only for questions that are specific to version 3.3 of OpenCV, for general questions use the [opencv] tag.

OpenCV is an open source computer vision library

Version 3.3 released in August 2017. Its documentation can be found here. The main change was:

The main news is that we promoted DNN module from opencv_contrib to the main repository, improved and accelerated it a lot. An external BLAS implementation is not needed anymore. For GPU there is experimental DNN acceleration using Halide

Github: https://github.com/opencv/opencv/releases/tag/3.3.0

Changes: https://github.com/opencv/opencv/wiki/ChangeLog

For more information, see .

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OpenCV 3.4.0 video contours/arclength error(s)

OpenCV version: 3.4.0 (couldn't create tag for it) While trying to approximate found contours I'm getting following errors: cv2.error: /io/opencv/modules/imgproc/src/shapedescr.cpp:237: error: (-215) count >= 0 && (depth == 5 || depth == 4) in…
GodIsAnAstronaut
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How to set cv::Mat to zero where another matrix is nonzero?

I have a matrix D which I would like to set to zero where another matrix T is zero and keep intact otherwise. In numpy, I'd do this: D[T==0]=0; but with cv::Mat, not sure how to do it. I tried this: D&=(T!=0); with this result: OpenCV Error:…
eudoxos
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Does OpenCV initialize weights matrix with zeros, cv::ml::ANN_MLP

Its mentioned on OpenCV docs here Artificial Neural Networks - Multi-Layer Perceptrons. Unlike many other models in ML that are constructed and trained at once, in the MLP model these steps are separated. First, a network with the specified…
Ayush Pandey
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openCV3: Not getting the expected output on morphologically transforming an image in opencv

I am trying to do top hat morphological transformation to an image but not getting the expected output for some reason. # Top Hat: difference between input image and opening kernel = np.ones((5,5),np.float32)/25 tophat = cv2.morphologyEx(img,…
Coddy
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Join different sized images with ROI

At the first contact with Java OpenCV (3.3.1, windows 8 x64) I'm trying to join two different size images with ROI dynamically. Here a bit of my code: Mat _mat = Utils.imageFileToMat(new File("angelina_jolie.jpg")); //Angelina's face Mat grayMat =…
jotapdiez
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OpenCV3.3.0 findContours error

I reinstall opencv today, and run my code I've written before. I got the error: OpenCV Error: Assertion failed (_contours.empty() || (_contours.channels() == 2 && _contours.depth() == CV_32S)) in findContours, file…
tomfriwel
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Webcam launching issues with OPenCV 3.3.0

I noticed I started having this issue as soon as I built the opencv_contrib module, because before my code was working and now I cannot access my web-cam with opencv even with the simple face detection program. Instead I get this error: gray =…
Durodola Opemipo
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could not use "cv2.imshow('Lena', img)" in jupyter notebook

It gives this error: error Traceback (most recent call last) in () 1 img = cv2.imread(imgpath) 2 ----> 3 cv2.namedWindow('Lena', cv2.WINDOW_AUTOSIZE) 4 cv2.imshow('Lena', img) 5…
Krishna
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OpenCV 3: What's the issue with Perspective Transformation in openCV 3.3.1?

I am trying perspective transformation example from the documentation but I am getting different result than the example. import cv2 import matplotlib.pyplot as plt import numpy as np img = cv2.imread('sudoku.png') rows,cols,ch = img.shape pts1 =…
Coddy
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How to Use OpenCV Submodule In Python?

How to use createLBPHFaceRecognizer() in opencv3.3, and Python 2.7.13? I Used Windows 64 bit OS because i find an error in syntax : import os import cv2 import numpy as np from PIL import Image recognizer =…
Willy Andika Putra
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