Ask Your Question

2ros0's profile - activity

2021-04-07 11:04:52 -0500 received badge  Famous Question (source)
2021-02-16 11:59:53 -0500 received badge  Notable Question (source)
2021-01-10 05:30:21 -0500 received badge  Famous Question (source)
2020-08-07 15:09:47 -0500 commented question python cv2 calls from c++

it's a c++ application with some embedded python using the python c api: https://docs.python.org/3/c-api/index.html

2020-08-06 13:07:52 -0500 commented question python cv2 calls from c++

haha yeah I see that, it's just there's a lot of python code in the other project that I would like embedded in this pro

2020-08-06 13:07:08 -0500 commented question python cv2 calls from c++

haha yeah I see that, it's just there's a lot of other python code in one project that I would like in my other project

2020-08-06 13:00:33 -0500 commented question python cv2 calls from c++

haha yeah I see that, it's just there's a lot of other python code

2020-08-05 19:15:24 -0500 commented question python cv2 calls from c++

Why embed python opencv in a c++ program? Because it's not just cv2, I'm using a lot of other code using python modules

2020-08-05 19:13:37 -0500 commented question python cv2 calls from c++

What do you mean?

2020-08-05 11:54:47 -0500 edited question python cv2 calls from c++

python cv2 calls from c++ Hi, I have embedded python in my c++ code. All other modules work fine, except for the cv2 m

2020-08-05 11:54:22 -0500 edited question python cv2 calls from c++

python cv2 calls from c++ Hi, I have embedded python in my c++ code. All other modules work fine, except for the cv2 m

2020-08-05 04:05:12 -0500 edited question python cv2 calls from c++

python cv2 calls from c++ Hi, I have embedded python in my c++ code. All other modules work fine, except for the cv2 m

2020-08-05 04:04:19 -0500 edited question python cv2 calls from c++

python cv2 calls from c++ Hi, I have embedded python in my c++ code. All other modules work fine, except for the cv2 m

2020-08-05 03:37:17 -0500 edited question python cv2 calls from c++

python cv2 calls from c++ Hi, I have embedded python in my c++ code. All other modules work fine, except for the cv2 m

2020-08-05 03:35:36 -0500 asked a question python cv2 calls from c++

python cv2 calls from c++ Hi, I have embedded python in my c++ code. All other modules work fine, except for the cv2 m

2020-08-05 03:35:23 -0500 asked a question python cv2 calls from c++

python cv2 calls from c++ Hi, I have embedded python in my c++ code. All other modules work fine, except for the cv2 m

2020-08-05 03:35:21 -0500 asked a question python cv2 calls from c++

python cv2 calls from c++ Hi, I have embedded python in my c++ code. All other modules work fine, except for the cv2 m

2020-06-13 15:30:55 -0500 received badge  Popular Question (source)
2020-01-25 16:00:39 -0500 received badge  Notable Question (source)
2020-01-18 14:57:37 -0500 received badge  Popular Question (source)
2019-07-13 04:39:52 -0500 received badge  Popular Question (source)
2019-07-05 04:58:53 -0500 received badge  Notable Question (source)
2019-01-15 04:46:45 -0500 received badge  Popular Question (source)
2018-09-07 15:12:24 -0500 marked best answer Encoding 32FC1 explained?

What does 32FC1 mean? Intuitively it should just be floating point matrix of one channel but the process that I am receiving images from has an array of uint8.

How do I convert this data such that each pixel value is stored as an int?

2018-09-07 15:11:45 -0500 marked best answer Compiling opencv with qt support (linux)

I followed the instructions page to download opencv3 source and installed with default settings. I assumed this would by default compile with qt support. But this doesn't seem to be the case as seen by the following error: OpenCV Error: The function/feature is not implemented (The library is compiled without QT support) in createButton

This question suggests the WITH_QT flag but I'm not sure where to set that. Moreover, when I run cv::getBuildInformation() as suggested in that question, this is some of the output I get. A couple of things I have noticed is:

QT 5.x:                      YES (ver 5.5.1)
QT OpenGL support:           NO
OpenGL support:              NO
VTK support:                 YES (ver 6.2.0)

Install path: /opt/ros/kinetic

but this is not the install path that I provided when I installed it. I can see it being installed in /usr/local, yet this is the output I get. I did have ROS installed separately, that also does come with opencv libraries so I'm not sure where the conflict is

2018-09-05 17:12:00 -0500 asked a question cv::Mat class member

cv::Mat class member Hi, I'm curious as to whether a cv::Mat class member is usually wrapped in a boost::shared_ptr is

2018-03-30 11:15:04 -0500 marked best answer derivation for perspective transformation matrix (Q)

Hi,

Opencv uses a perpective transformation matrix Q to convert pixels with disparity value into the corresponding [x, y, z] using the reprojectImageTo3D function. After searching on this site for a bit I found out that the matrix Q is as follows:

Q = |1 0 0 -Cx
    |0 1 0 -Cy
    |0 0 0 f
    |0 0 -1/Tx (Cx - Cx')/Tx

I looked for equations to derive this but couldn't find any. I know about these matrix equations: image description

Is there a way to work back/invert this to get the matrix form of Q or am I missing something?

edit: projection matrices are the follows:

Pright = |F skew Cx F*Tx
         |0 Fy Cy 0
         |0 0 1 0

and a similar one for Pleft without the Tx factor. I guess what I'm looking for is a derivation from the projection matrix Pright to the reprojection matrix Q. I would assume there's an inversion or something to get from one to the other.

Thank you

2018-03-28 12:22:17 -0500 edited question derivation for perspective transformation matrix (Q)

derivation for perspective transformation matrix (Q) Hi, Opencv uses a perpective transformation matrix Q to convert p

2018-03-28 12:21:55 -0500 edited question derivation for perspective transformation matrix (Q)

derivation for perspective transformation matrix (Q) Hi, Opencv uses a perpective transformation matrix Q to convert p

2018-03-26 11:10:19 -0500 edited question derivation for perspective transformation matrix (Q)

derivation for perspective transformation matrix (Q) Hi, Opencv uses a perpective transformation matrix Q to convert p

2018-03-26 11:09:11 -0500 edited question derivation for perspective transformation matrix (Q)

derivation for perspective transformation matrix (Q) Hi, Opencv uses a perpective transformation matrix Q to convert p

2018-03-26 11:07:35 -0500 edited question derivation for perspective transformation matrix (Q)

derivation for perspective transformation matrix (Q) Hi, Opencv uses a perpective transformation matrix Q to convert p

2018-03-26 11:05:49 -0500 asked a question derivation for perspective transformation matrix (Q)

derivation for perspective transformation matrix (Q) Hi, Opencv uses a perpective transformation matrix Q to convert p

2018-02-16 22:44:53 -0500 edited question opencv rgb to gray conversion equation reasoning

opencv rgb to gray conversion Hi, The tutorial page on opencv docs mentions the following equation when converting rgb

2018-02-16 22:44:28 -0500 edited question opencv rgb to gray conversion equation reasoning

opencv rgb to gray conversion Hi, The tutorial page on opencv docs mentions the following equation when converting rgb

2018-02-16 22:43:29 -0500 edited question opencv rgb to gray conversion equation reasoning

opencv rgb to gray conversion Hi, The tutorial page on opencv docs mentions the following equation when converting rgb

2018-02-16 22:37:20 -0500 asked a question opencv rgb to gray conversion equation reasoning

opencv rgb to gray conversion Hi, The tutorial page on opencv docs mentions the following equation when converting rgb

2018-02-06 16:57:49 -0500 asked a question Compiling opencv with qt support (linux)

Compiling opencv with qt support (linux) I followed the instructions page to download opencv3 source and installed with

2018-02-05 20:55:56 -0500 commented question The library is compiled without QT support in function displayOverlay

where to use the WITH_QT=ON option? @Liimyd

2017-12-01 13:24:36 -0500 edited question Best calibration checkerboard config (size and square length) ?

Best calibration checkerboard config (size and square length) ? Hi, I would like to know how I should go about picking

2017-12-01 13:22:39 -0500 asked a question Best calibration checkerboard config (size and square length) ?

Best calibration checkerboard config (size and square length) ? Hi, I would like to know how I should go about picking

2017-09-27 15:18:18 -0500 edited question Multiple imshow windows without needing waitkey in same function

Multiple imshow windows without needing waitkey in same function Hi, I'm looking to have a GUI that has multiple areas

2017-09-27 10:23:40 -0500 commented question Multiple imshow windows without needing waitkey in same function

@berak @Tetragramm what if you made it general enough - it might take a few days to create but then you can use it for y

2017-09-26 22:06:37 -0500 received badge  Teacher (source)
2017-09-26 21:40:45 -0500 edited answer canny edge detection with two input arrays

This is a new overloaded member function since OpenCV 3.2. It means that you can provide an arbitrary gradient image suc

2017-09-26 21:39:52 -0500 marked best answer canny edge detection with two input arrays

Hi,

I saw a version of the canny function with two input arrays in the samples/cpp/edge.cpp. Here is a code excerpt:

/// Canny detector with scharr
Mat dx,dy;
Scharr(blurImage,dx,CV_16S,1,0);
Scharr(blurImage,dy,CV_16S,0,1);
Canny(dx, dy, edge2, edgeThreshScharr, edgeThreshScharr*3);
/// Using Canny's output as a mask, we display our result
cedge = Scalar::all(0);
image.copyTo(cedge, edge2);
imshow(window_name2, cedge);

All the documentation/API I can find just has the single input array into canny like so:

void Canny(InputArray image, OutputArray edges, double threshold1, double threshold2, int apertureSize=3, bool L2gradient=false )

And so what am I missing?

2017-09-26 21:39:32 -0500 commented question Multiple imshow windows without needing waitkey in same function

like what?

2017-09-26 20:33:07 -0500 received badge  Self-Learner (source)