The copy operation for mat: cv::Mat::clone() or cv::Mat::copyTo(). Most of the copying interfaces are under the reference count mechanism. All image information is expressed by a single matrix in OpenCV. The tuple (r, g, b) is used by men to watch the colorful world. #include <iostream> #include <stdio.h> #include <opencv2/opencv.hpp> Read more…
Learn from website：https://sites.google.com/site/yonasstephenfyp2013/updates/tutorialinstallingopencvonmacosxmountainlionDownload opencv-4.0.1 compressed file and extract it, then go into it and build project. mkdir opencv_build cd opencv_build cmake -G “Unix Makefiles” ../ Generate Makefile successfully： — Found JNI: /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/Library/Frameworks/JavaVM.framework — Found VTK 8.1.1 (/usr/local/lib/cmake/vtk-8.1/UseVTK.cmake) — Looking for dlerror in dl — Looking for dlerror in dl – Read more…
After upgrade vtk from 7.1.0 to 8.2.0, the old project shows a warning window about VTKWidget. The newest vtk-qt program suggest me not to use old QVTKWidget anymore, so I rewrite my qt UI file I have qt UI file as the following code snippet, a few widgets are put Read more…
Draw The Plane Manually We can create a big plane if we know its origin and normal. The algorithm class vtkPlaneSource is a solution for it, but the generated plane is too small, it’s hard to create a big plane based on vtkPlaneSource, so I wrote a function for the Read more…
They are many different cells in VTK, they can be divided into two kinds, linear cells, and non-linear cells. The following images are from VTKUsersGuide. Linear Cells Non-Linear Cells Although vtkUnstructuredGrid and vtkPolyData are similar, there are substantial differences. vtkPolyData can only represent cells of topological dimension 2 or less Read more…
Here is relevant introduction about vtkImageData from VTKUsersGuide. A vtkImageData dataset is defined by data dimensions, interpoint spacing, and the origin (i.e., lower-left corner) of the dataset. If the dimension of the dataset is two, then we call the vtkImageData dataset an image, and it is composed of vtkPixel cell Read more…
Last night I read some pages in VTKUsersGuide to learn VTK factory mechanism. I got the basic steps of defining my own factory and use it. Implement virtual function which is declared in vtkObjectFactory. virtual const char* GetVTKSourceVersion(); virtual const char* GetDescription(); Create Object Use the protected function RegisterOverride which Read more…
Email is used in our working frequently, we have to send emails to different people, it is too boring to send similar content to different friends manually. Python can help us to handle the task successfully, we need to use the library smtplib and email.mime.text. I use my sina account Read more…
Almost every developer know how to implement the bubble sort for a simple array. We just need to travel over the array in two levels and swap the adjacent elements in the second level if their values’ order is not correct. The algorithm implement with Python is in the following Read more…