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Questions tagged [opencv3.0]

OpenCV (Open Source Computer Vision) is a library for real time computer vision. (This tag is for questions about OpenCV 3.0. Use [opencv] for general questions.)

OpenCV is an open source computer vision library

Version 3.0 released in June 2015. Its documentation can be found here.

For more information, see .

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python cv2 feature matching give different results

When I match SIFT feature using FLANN,I found same input descriptor give different match pairs in same process. python code: import cv2 def match(des_q, des_t): FLANN_INDEX_KDTREE = 1 ratio = 0.7 index_params =…
FancyXun
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Using GPU in OpenCV

If I want to use my computer's GPU with OpenCV, is it necessary that I build OpenCV from source with CUDA enabled? Or can I install OpenCV with CUDA support via apt-get? I noticed the following 2 packages in apt-get: libopencv-gpu-dev - development…
Guilty Spark
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plt.imshow works on inverse FFT image but cv2.imwrite dosen't. Any Ideas why?

Ok, so I have been scratching my head over this for some time now. I took a inverse FFT of an image and I can display it with cv2.imshow just fine. plt.subplot(131), plt.imshow(img_back) plt.title('Subtracted'), plt.xticks([]),…
Utopia
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opencv trackbar not showing

include #include #include using namespace std; using namespace cv; Mat srimg, deimg; int max_brightness = 100; int slider_b = (max_brightness / 2); void on_change_brightness(int, void*) { int brightness =…
Allaye
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How to print coordinate of objects with diiferent colors? Python3 OpenCV

I try to detect 3 objects of blue colore and 3 objects of pink colore in one program, after that print coordinate of object's center. But coordinates of different centers are identical or real strange(I subtracted from one value another, these…
Sandra Archipova
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Check if parking space is full with Python 2.7 and OpenCV 3

I am trying to make an autonomous car park into a parking lot where if there is a blue line a slot is considered full and if there isn't it is considered empty: I have tried many things from basic color detection to edge detection and even feature…
huvarda
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why is sorted(contour)[0] different from sorted(contour)[:1]

I am trying to find the biggest contour in an image which contains 2 contours and one of those are not close line. the contour line is cut from the edge of the image. the other one is close and consist an area. roi_cnts = sorted(roi_cnts, key =…
YJJ
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Check the neighbour pixels of a connected component

I'm using opencv to extract text from images like this. Right now my goal is in trying to delete the most of the walls/windows/doors I can while leaving the text intact. This is what I came up with: def process_image(path, out_path): image =…
Alessandro
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opencv-python: haveOpenCL return False

Should return True if the the prebuilt binaries are compiled with OpenCL support. I've seen many examples where it just works out of the box. So my assumption is that the binaries are built with OpenCL support. So why might it not be working for…
Veneet Reddy
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Where is the Aruco marker {0,0,0}?

When drawing the detected marker on screen , I see there is small rectangle on top left corner and the Axis are drawn in the center of the marker. When I get translation of the Aruco marker , are they related to the center of the marker or to the…
Alophind
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Structured Edge detection - OpenCV - IOS

I am trying to use piotr dollar's model to detect edges in IOS as suggested here. https://docs.opencv.org/3.1.0/d0/da5/tutorial_ximgproc_prediction.html String modelFilename = "./model.yml.gz"; Ptr pDollar =…
cypher
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Extracting text OpenCV Contours

I tried doing ocr of each individual contour using tesseract but not getting proper text out of it. Contour Identification is done properly by using Extracting text OpenCV. Please suggest.
user2789964
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Image rectifying after stereo calibration using openCv3

I'm new to stereo vision, i'm trying to get a good stereo calibration. I calibrate each camera and i got a good results: RMS1:0.22 ,RMS2: 0.26 For the stereo calibration i got: RMS: 0.75 Is this an acceptable value? After that i used…
Imen Jmal
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Issue with T-API(with OpenCL) python3

I'm experimenting with T-Api of opencv python. Currently I'm trying to convert a normal RGB image to gray scale and save it with T-Api enabled. Here's the snippet import cv2 import dlib im = cv2.UMat(cv2.imread('input.png',1)) print(im) imMat = …
Saikiran
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Why is OpenCV performing poorly on Raspberry Pi 3B+?

Running on a Raspberry Pi 3B+ (Arm processor) OpenCV C++ 3.4 static libs built libs from source with relevant flags -DENABLE_NEON=ON -DCMAKE_BUILD_TYPE=Release -DWITH_V4L=ON Using a basic ELP USB webcam (not using raspi camera because I eventually…
idle
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