Most voted "opencv" questions
Opencv is a multiplatform and *open source* library for developing applications linked to Computer Vision.
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13
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answer1704
viewsWhat are the terms "Cascade" and "Classifier" in relation to computer vision?
Always when I read something about Opencv and computer vision I come up with two terms that are Cascade and Classifier, these terms leave me very confused as to what they may be or mean. Therefore,…
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12
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answers955
viewsPutting a background color after recognizing and cropping people’s faces
I found a tutorial of an app that recognizes the face of people using the camera and creates a rectangle around the recognized face. - (void)processImage:(Mat&)image; { Mat grayscaleFrame;…
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11
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answer389
viewsHow to trace letters and cut them?
I have this image below. As you can see, they are together. In this case, it’s a "7", "h" and "a". It is possible to scan the image to find them and then cut them where exactly you found them? I’m…
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10
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answer5452
viewsBasic image editing using Opencv
Hello, I’m learning to use the features that Opencv offers for image processing and the following question has arisen: How do I edit only a predetermined area of an image? To facilitate the…
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9
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answers295
viewsOpencv haartraining - Out of memory
I have 30 positive images and 60 negative images. When I tried to run haartraining with 4GB of memory and Quadcore processor, I get this error message: OpenCV ERROR: Insufficient memory (Out of…
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answer211
viewsQT + Opencv on Mac Os 10.10.3 with error: Symbol(s) not found for Architecture x86_64
I recently installed Qt Creator and Opencv. I was able to easily compile QT and Opencv separately. But I can’t compile both together. My file .pro is like this:…
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8
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answer380
viewsHow to remove the background of an image using Watershed on android?
I’m developing an app that classifies images of wounds. For this, I need to highlight the region of interest of the background to facilitate the work of the classification algorithm. The user uses…
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answers1315
viewsPython and Opencv add points and Houghline
I’m doing my TCC in electrical engineering, where I have to automate a quadricoptero to take pictures of plantations, so far so good. The problem is that my teacher asked me to make a code in python…
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answer2289
viewsHow to remove image noises using opencv - python?
I am working with skin images, in the recognition of skin spots, and due to the presence of noises, mainly by the presence of hair, it is more complicated this work. I have an example image in which…
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7
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answer513
viewsHow to remove noises and hairy image lines?
I’m working on hair removal on skin images. Researching the literature, the means to achieve my goal, applying some techniques of segmentation and removal of noise in images. Which I’m applying to.…
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7
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answers602
viewsError splitting image in half using Python
I’m trying to split an image in half using the code below, but I’m having a feedback error. Code: import cv2 import numpy as np # Read the image img = cv2.imread("IMD015.png") width = img.shape #…
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answer126
viewsHow to change the color when drawing a line segment that belongs to a circle?
I’m trying to draw in an image 400 × 400. The first drawing is a line defined by the equation ax + by + c = 0. When to replace x and y and the result is 0 the point belongs to straight, then change…
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answer686
viewsHow to train two objects with different sizes for recognition in Opencv
Hello, I am using Opencv version 2.4.11 to train license plate recognition for a parking software. The problem is when training to identify the car plate, truck, truck where the plates used by them…
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answer1928
viewsHow to connect DVR camera in Java?
I’m having a question, I’ve searched the internet but I can’t find anything consistent: how to connect with a DVR camera (not IP camera) using Java? I already use Opencv and can connect on IP…
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answer620
viewsWhy does my image recognition training in Opencv generate transparent samples?
I’m using Opencv and trying to generate a file. vec to do image recognition training, but whenever I file and try to read it, I see images as if some parts of my positive are transparent! (I…
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answer992
viewsImage segmentation with Canny Edge Opencv
I’m trying to target the edge of both the iris and the pupil using Canny Edge from Opencv. However all the parameters I used do not meet the criterion of leaving well delimited the two edges. The…
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answer490
viewsStereo camera calibration via openCV chessboard
I am trying to calibrate a stereo camera using openCV, but the function findChessboardCorners is always returning False, I believe it is in function of high image distortion. Any hint of…
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answer247
viewsRemove eye shine on image
Well, I’m trying to apply Canny edge to the image but the brightness that is contained in the pupil hinders the result because to have an edge with cv2.Canny() or feature.canny() needs there to be a…
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answer1040
viewsImage recognition within a larger image
I would like to do a part of my application, where the user would upload an image full of drawings inside, he would then select an area of the image and I would search the entire image uppada,…
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4
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answer1617
viewsHow to show content captured by camera in full screen in Opencv?
Would you like to know how to show the content captured via webcam (by the Pture video) in a window that occupies the entire screen? Only appears in a small window. You have to change something in…
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4
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answer135
viewsDoubt: how to use python scripts for web?
I want to make a web application that will read colors in RGB logos and create suggestions of color scales for websites. The algorithm will be in python, using Opencv. The client moves the image…
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answer1728
viewsHow to save a video captured by webcam without showing it using Opencv in python?
I’m starting to learn Computer Vision. I’m using the Opencv module for Python 3. Reading tutorials, discover the following script: import cv2 cap = cv2.VideoCapture(0) fourcc =…
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answer421
viewsHow to copy integer matrix for Mat type in Opencv?
Would you like to know how to copy an integer array to an Opencv Mat type data ? The following is an example I created to illustrate my goal, which corresponds to a given user generated matrix (…
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4
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answer202
viewsImplement a blink counter in the face detection
As q do to display the amount of flashes of people detected at the time. The code below detects face with Haar Cascade, where it displays a face counter. from __future__ import print_function…
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4
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answer1206
viewsHow to remove area of interest from the background of an image?
I am starting to work with image processing in pattern recognition, and I need to do pre-processing of the images I will use. First, I need to highlight the region of interest from the background of…
python opencv image-processing artificial-intelligenceasked 5 years, 8 months ago Tecnologia da Net 374 -
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answer1677
viewsCalculate percentage of certain colors in an image
I have a program that reads an image and checks if there are certain colors in that image, if it does paint each pixel a certain color. I couldn’t find materials on the Internet that could help me,…
python-3.x opencv image-processing histogramasked 5 years, 5 months ago Marcos Paulo S. Rezende 351 -
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answer390
viewsCalculate percentage of a face in an image
How would the calculation of porcetangem of a face in an image? Suppose I had a 3x4 photo of a user, but he had a lot of his hair covering his face. Is there any way to detect that the image does…
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answers114
viewsAndroid + Opencv: Surfacetexture has been abandoned
I’m developing an Eclipse application with Opencv. The application consists of detecting and recognizing objects (predefined in the database) in real time. Initially has a menu where the user can…
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3
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answer3056
viewsImage editing using Opencv with no ready-made functions
I have the following picture shown below and I need to turn it into gray and then binarize it. I use the following code to show it on the screen cv::Mat img = cv::imread("lena.jpg");// Lê a imagem…
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3
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answer1631
viewsHow to delete components from an image using python?
I’m a beginner in python and would like to know how to eliminate components (red, blue or green) of an image using python, I downloaded some image processing libraries (like opencv). I wonder if…
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answer58
viewsUse Opencv in Ubuntu c++
I am using Ubuntu with Opencv to develop a computer vision method, previously used in windows Opencv and put the following configuration in qtCreator to recognize Openccv. INCLUDEPATH +=…
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answer4136
viewsHow to convert color image to black and white and highlight only the white of a video
I would like to highlight the white color using webcam and opencv python, however my image is colored, first I need to convert to black and white and then I would like to highlight only white, which…
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answer56
viewsGenerate new centered image at one point
I did a processing and found a point in the image that meets my criteria. I need to cut the original image into a smaller one (120x120) that has that center point. I tried to do the following: img =…
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3
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answer87
viewsDepth in some opencv methods
What is the parameter depth that appears in many opencv functions? For example from filter2D(), what I understood by what ta in the documentation would be the number of bits to represent the…
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answer594
viewsSave an image to a Mysql database using Python
I don’t know how to save the image in the database. foto =cv2.imread('imagem.jpg') hora = str(hora.day) + '/' + str(hora.month) + '/' + str(hora.year) + '-' + str(hora.hour) + ':' + str(hora.minute)…
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answer428
viewsError processing large images with openCV
I’m trying to process an orthomosaic, the problem is that the image is too big, with other smaller maps I can process normally, but when I go to process a bigger map it from the error in converting…
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3
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answers434
viewsHow to create a counter in face detection?
As you can see in the code below, it only detects the faces with Haar Cascade, I would like to know how to display on the webcam the amount of people detected at the time. from __future__ import…
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3
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answer85
viewsArray always getting the same value [Loop in two matrices simultaneously]
My program scans an image and assigns color values R,G, B the variables that were compared with matrices containing the colors R,G, B asphalt and earth called auxAsfalto and auxTerra. The point is,…
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answer48
viewsSetting an array element with a Sequence
I’m with a program in python and opencv that reads an image and then checks the colors of the image at each position of two for nestled. How I’m making a threshold in the image to facilitate the…
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answers153
viewsMatch of the contours
I created the program below, to make the correction of tests. https://gist.github.com/andreemidio/d2cdf3d301fd8df1677e9a315ff845f0 I was able to outline, identify the fillers, I need to match the…
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answer90
viewsImage transformation according to parameters of a photo
I have an aerial photo of a lake and I have a file . geojson with a polygon that represents the outline of that lake on a real map. I am converting latitude, longitude and altitude to X, Y, Z using…
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2
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answer866
viewsCan I call one program inside another?
I want to connect one program inside the other because I have a project (main, 7 Classes) in C++/Opencv that should call a program also in C++/integrated with Tesseract, pass and receive an Object…
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answers1776
viewsAccessviolationexception - Read or write attempt in protected memory
I’m working with the OPENCVSHARP (Opencv) to access a camera Ps3eye (Playstation 3) camera in C#. But I am having a serious problem with protected memory! I use visual studio 2010 on Windows7. Code:…
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answer245
viewsIs it possible to access the Hough transform accumulator using opencv?
I am with this small prolema, I searched a lot on the internet and in the documentation but I did not find anything related, I need to know what the accumulation value of each circle generated by…
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answer47
viewsHow to turn a cv::Mat into ipcMatrix<ipcRGB>?
Does anyone know if there’s an easy way to turn a cv::Mat in ipcMatrix<ipcRGB>?…
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answers560
viewsRecognize color patterns with Opencv
I am developing a computer vision algorithm for robot football. I started learning Opencv a short time ago. And I have a question in the following part: I wonder, how I can make the division of each…
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answer112
viewsHow to install OPENCV in PHP on a WAMP server?
I need the OPENCV image processing function in PHP, but I’m having trouble installing it in windows. how to proceed ?
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answer564
viewsGrayscale in Images - OPENCV
Good afternoon Personal, I have an image . bmp and want to turn it into grayscale (0-255), through Opencv with C++(I don’t want to save this image in grayscale). From there, I want to go through the…
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answers860
viewsImport in Opencv installation
Today I tried to reinstall the opencv library on my computer, I did it by script pip, which downloaded the file .whl by the website: http://www.lfd.uci.edu/~gohlke/pythonlibs/. After the library was…
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answers4641
viewsHow to install Opencv
i would like to know how to install the latest version of Opencv 3.2 on linux Ubuntu 14.04. I was able to install and put to compile in codeblocks using C++ following a tutorial. But my goal is to…