Stack Overflow
Stack Overflow

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 .

2111 questions
14
votes
2 answers

How do I use SIFT in OpenCV 3.0 with c++?

I have OpenCV 3.0, and I have compiled & installed it with the opencv_contrib module so that's not a problem. Unfortunately the examples from previous versions do not work with the current one, and so although this question has already been asked…
leinaD_natipaC
  • 4,299
  • 5
  • 21
  • 40
12
votes
2 answers

HoughCircles Doesn't detect circles correctly in OpenCV

I am using Visual Studio 2015, OpenCV.3 and EmguCV.3. My code represented below and the result is shown in the picture. I know that the problem is the input values of HoughCircles function, but I don't know which inputs are suitable for this…
mjyazdani
  • 2,110
  • 6
  • 33
  • 64
12
votes
1 answer

OpenCV lines/ruler detection

I'm trying to detect ruler on the image, and I'm going to follow the next process: 1) prepare image (blur,Canny, ect.) 2) detect lines 3) prepare set of parallel lines so, I have an image: that app converts to this: next I've tried HoughLinesP…
Siarhei
  • 2,358
  • 3
  • 27
  • 63
12
votes
3 answers

Error importing cv2 in python3, Anaconda

I get the following error when importing opencv in python: > python >>> import cv2 Traceback (most recent call last): File "", line 1, in ImportError: /usr/lib/x86_64-linux-gnu/libpangoft2-1.0.so.0: undefined symbol:…
krasin
  • 123
  • 1
  • 6
12
votes
3 answers

OpenCV - specify format while writing image to file (cv2.imwrite)

I want to save an image using opencv's imwrite without any extension. I know image format in cv2.imwrite is chosen based on the filename extension. Is there a way to specify the compression format while calling the function, or would I have to…
kampta
  • 4,748
  • 5
  • 31
  • 51
12
votes
1 answer

Feature detection with patent-free descriptors

I need the feature detection algorithm. I'm fed up surfing on the web finding nothing but SURF example and hints how to do that, but I did not find an example with other than patented descriptors like SIFT or SURF. Can anybody write an example of…
denis631
  • 1,765
  • 3
  • 17
  • 38
12
votes
2 answers

How can I stitch images from video cameras in real time?

I use 4 stationary cameras. Cameras do not move relative to each other. And I want to stitch video images from them into the one video image in real time. I use for this OpenCV 2.4.10, and cv:stitcher class, like this: // use 4…
Alex
  • 12,578
  • 15
  • 99
  • 195
11
votes
1 answer

How to change the colour of an image using a mask?

I am writing a code to change the color of hair in the facial picture of a person. Doing this I made a model and was able to get a mask of the parts of the hair. But now I am stuck at a problem how to change the color of it. Below is the output mask…
Pratham Jindal
  • 123
  • 1
  • 1
  • 6
11
votes
1 answer

What is the difference between cv2.StereoSGBM_create() and cv2.StereoBM_create() functions for disparity mapping on opencv3?

I am trying to understand the disparity mapping functions of opencv I came across two methods cv2.StereoSGBM_create and cv2.StereoBM_create I don't quite understand the difference. Also, what are the properties of the functions such as…
BigZee
  • 456
  • 5
  • 22
11
votes
2 answers

opencv clahe parameters explanation

I would like to know proper explanation of the clahe parameters i.e clipLimit and tileGridSize. and how does clipLimit value effects the contrast of the image and what factors(like image resolution, object sizes) to be considered to select…
hariprasad
  • 838
  • 1
  • 8
  • 16
11
votes
1 answer

Convert a single color with cvtColor

I have a color that I want to convert to a different color space. Is it possible to use cvtColor on a cv::Vec3f directly without creating a 1x1 cv::Mat and populating it with that pixel, using cvtColor on the cv::Mat, then getting the only pixel out…
David Doria
  • 9,873
  • 17
  • 85
  • 147
11
votes
1 answer

Detect parking lot by opencv

This program identifies the objects if it is single row (smaller image). from __future__ import division from collections import defaultdict from collections import OrderedDict from cv2 import line import cv2 from matplotlib import pyplot as…
Vijay Innamuri
  • 4,242
  • 7
  • 42
  • 67
11
votes
1 answer

OpenCV findContours in python

I am working in python on openCV 3.0. In order to find the largest white pixel region, first of all thresholded gray image to binary image. import cv2 import numpy as np img = cv2.imread('graimage.png') img = cv2.resize(img,(400,500)) gray =…
Kaira
  • 141
  • 1
  • 2
  • 4
11
votes
3 answers

Opencv 3 SVM training

As you may know, many things changed in OpenCV 3 (in comparision to the openCV2 or the old first version). In the old days, to train SVM one would use: CvSVMParams params; params.svm_type = CvSVM::C_SVC; params.kernel_type =…
Jack L.
  • 1,257
  • 2
  • 17
  • 37
10
votes
3 answers

What does the TM_CCORR and TM_CCOEFF in opencv mean?

What does the TM_CCORR and TM_CCOEFF in opencv mean? I found that TM_CCORR stands for the correlation coefficient. However, the TM_CCOEFF seams also to be the correlation coefficient due to its naming. Do you know for what the abbrevations…
Rene B.
  • 6,557
  • 7
  • 46
  • 72
1 2
3
…
99 100