2ros0's profile - activity

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

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

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

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

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

What do you mean?

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

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

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

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

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

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

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

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

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?

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

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

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:

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

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

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

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

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

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

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

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

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

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

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

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

where to use the WITH_QT=ON option? @Liimyd

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

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

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

@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

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

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?

like what?