rezaee's profile - activity

I tried to disable build_opencv_python in cmake gui and i think it worked.

I tried to disable python in cmake gui and i think it worked.

I checked them in CMake gui, all of them are like you wrote above by default!

Where should I do these changes?

C:\Users\m\AppData\Local\Temp\ccS5IfdC.s|20393|Error: invalid register for .seh_savexmm| I am trying to use OpenCV 3.4.1

@LBerger : Yes. What does radius = 5 mean for example? How long it will take on the screen?

@berak: I found this formula in Oreally's Opencv3 book. I edited my question and added more information.

Question about the sigma indexes inside FNLMD formula I am interested to know, how a summation(Sigma) works if there are

@berak: I found this formula in Oreally's Opencv3 book.

@LBerger I put more information.

What does "sig[i] = cv::Mat(sigv).clone().reshape(1);" do? i KNOW reshape() get a vector and make a matrix from it. But

What does "sig[i] = cv::Mat(sigv).clone().reshape(1);" do? i KNOW reshape() get a vector and make a matrix from it. But

iterator belongs to what in "cv::Mat_<cv::vec3b>::iterator" Maybe this is a C++ programming question, but I want t

Question about the sigma indexes inside FNLMD formula I am interested to know, how a summation(Sigma) works if there are

What is the "Radius" scale in OpenCV functions? I was reading a book about OpenCV that it didn't mention what is the sca

I am reading a book about OpenCV, it speaks about some derivative of images like sobel. I am confused about image derivative! What is derived from? How can we derived from an image? I know we consider an image(1-channel) as a n*m matrix with 0 to 255 intensity numbers. How can we derive from this matrix?

A piece of text of the book:

Derivatives and Gradients

One of the most basic and important convolutions is computing derivatives (or approximations to them). There are many ways to do this, but only a few are well suited to a given situation.

In general, the most common operator used to represent differentiation is the Sobel derivative operator. Sobel operators exist for any order of derivative as well as for mixed partial derivatives (e.g., ∂ 2 /∂x∂y).

Yes, but how does it work?

What does it mean “derivative of an image”? I am reading a book about OpenCV, it speaks about some derivative of images

D:\Opencv_Tools\opencv\sources\3rdparty\protobuf\src\google\protobuf\stubs\io_win32.cc|94|error: 'nullptr' was not decla

Where can I find descriptions of Java OpenCV? In this page(https://docs.opencv.org/trunk/javadoc/org/opencv/core/Mat.htm

Are there any clear and working installation guide to use OpenCV c++ in Android Studio? I have tried a some of installat

Are there C++ version of Python examples in Opencv? I found this example here: https://docs.opencv.org/3.1.0/db/d5b/tut

Is there a simple way to see the intensity of each point of an image? I am using threshold on a batch of images(more tha

Thank you!

I am trying to convert this piece of python code to c++:

import cv2
import numpy as np

##(1) read into  bgr-space
img = cv2.imread("test2.jpg")

##(2) convert to hsv-space, then split the channels
hsv = cv2.cvtColor(img, cv2.COLOR_BGR2HSV)
h,s,v = cv2.split(hsv)

##(3) threshold the S channel using adaptive method(`THRESH_OTSU`) or fixed thresh
th, threshed = cv2.threshold(s, 50, 255, cv2.THRESH_BINARY_INV)

##(4) find all the external contours on the threshed S
_, cnts, _ = cv2.findContours(threshed, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
canvas  = img.copy()
#cv2.drawContours(canvas, cnts, -1, (0,255,0), 1)

## sort and choose the largest contour
cnts = sorted(cnts, key = cv2.contourArea)
cnt = cnts[-1]

## approx the contour, so the get the corner points
arclen = cv2.arcLength(cnt, True)
approx = cv2.approxPolyDP(cnt, 0.02* arclen, True)
cv2.drawContours(canvas, [cnt], -1, (255,0,0), 1, cv2.LINE_AA)
cv2.drawContours(canvas, [approx], -1, (0, 0, 255), 1, cv2.LINE_AA)

## Ok, you can see the result as tag(6)
cv2.imwrite("detected.png", canvas)

But from threshold line, I don't know how to get the outputs? Actually I don't know what are the outputs? integer? Mat?

Thanks alot! May you help to convert this line too: cnts = sorted(cnts, key = cv2.contourArea) Should I use for loop her

Thanks alot! May you help to convert this line too: _, cnts, _ = cv2.findContours(threshed, cv2.RETR_EXTERNAL, cv2.CHAIN

Thank you! It was really cool, but as you know it's interactive program, but I need my program to do it automatically.

Thank you! It was really cool, but as you know it's interactive program, but I need my program do it automatically.

Converting python opencv code to c++ problem! I am trying to convert this piece of python code to c++: import cv2 impor

What's the best idea to remove defferent backgrounds from images? I want to convert this photo: to this one: And t

What's the best idea to remove defferent backgrounds from images? I want to convert this photo: enter image description

Can I use this wireless video sunglasses to capture images and process in real-time? I have not seen these sunglasses be

Can I show some image in my program beside the executation at the same time? I had a problem with GTK+. I had a program

[ 20%] Built target opencv_cvv_automoc Makefile:160: recipe for target 'all' failed make: *** [all] Error 2 It's the sec

How to use some basic OpenCV functions upon MCUs? For example, building an empty matrix (Mat) and draw some shapes or co

I am newbie in OpenCV, so I don't know can I ask this kind of question here or not? I like to draw a sequence of points as a line on OpenCV3.3.0. I think I can collect this sequence by "vector<point>" although I don't know is this the best idea or not? Lets consider I have these points vector:

 vector<Point> vec = { Point(0,0),Point(10,10),Point(20,20), Point(30,30), Point(40,40), Point(50,50) };

And like to draw them in an empty Mat as an 50*50 pixel image. So it would be the images diameter. But I don't know how can I do this? I searched and found the "line" function, but it has only to "starting and end" points. should I use many line functions in sequence? there isn't better solution for this?

I tried to do it by this code but it thrown in an exception:

#include <opencv2/opencv.hpp>
#include <iostream>

using namespace std;
using namespace cv;

void MyLine(Mat img, Point start, Point end);
Mat im = Mat::zeros(100, 100, CV_8UC1);
Mat img = Mat::zeros(100, 100, CV_8UC1);
vector<Point> vec = { Point(0,0),Point(10,10),Point(20,20), Point(30,30), Point(40,40), Point(50,50) };

    int main()
    {

        Point start= Point(0, 0);
        Point end = Point(50, 50);

        MyLine(img, start, end);
        namedWindow("image", WINDOW_AUTOSIZE);
        imshow("image", im);
        waitKey(0);
        return 0;
    }

    void MyLine(Mat img, Point start, Point end)
    {
        int thickness = 2;
        int lineType = 8;
        for (int i = 0; i < 7; i++)
        {
            line(img,
                vec[i],
                vec[i+1],
                Scalar(255, 255, 255),
                thickness,
                lineType);
            im += img;

        }
    }

I want to draw a line of points I am newbie in OpenCV, so I don't know can I ask this kind of question here or not? I li

I want to plot my mouse location I am newbie in OpenCV, so I don't know can I ask this kind of question here or not? I l

I want to plot my mouse location I am newbie in OpenCV, so I don't know can I ask this kind of question here or not? I l

I had this exact error message on windows 10 with VS2017 and OpenCV3.3.0 and couldn't find a solution. so switched to Ubuntu 16.04 and tried OpenCV3.3.0 with codeblocks. but I got the same error again!!

My code:

#include <iostream>
#include <opencv2/opencv.hpp>



using namespace std;
using namespace cv;

int main()
{

    Mat img=imread("home/m/1.jpg");
    namedWindow("image", WINDOW_AUTOSIZE);
    imshow("image", img);
    waitKey(0);
    return 0;
}

The error message:

OpenCV Error: Assertion failed (size.width>0 && size.height>0) in imshow, file /home/m/opencv/modules/highgui/src/window.cpp, line 333
terminate called after throwing an instance of 'cv::Exception'
what(): /home/m/opencv/modules/highgui/src/window.cpp:333: error: (-215) size.width>0 && size.height>0 in function imshow

Aborted (core dumped)

Should I remove OpenCV3.3.0 and install 3.2.0 ?

Thank you, the problem solved by adding "/" before the home!