I have downloaded openCV 2.4.4 in a windows executable form. It had all the libraries that are needed pre built.
Now i am creating an object detection program that requires creating a haar or lbp classifier. I have found that opencv_traoncascade is now the preferred utility and the others are deprecated. The problem is that i am not able to find that utility in opencv2.4.4.exe which i downloaded. There is a folder traincascade but all it has are some hpp files.
Is there a way i can get it, i dont want to checkout the trunk and build it using cmake.
Also some reference to good tutorials explaining thus new utility will be helpful.
You have (as my exp.) two ways to do you want: use CMake or create your project and copy code you're need from opencv (this is not good idea:)).
I dont understand what you mean:
i dont want to checkout the trunk and build it using cmake
if you already
downloaded openCV 2.4.4 in a windows executable form
you have all to use CMake: open cmake, set source code: "...\opencv" and binary path (may be the same). Next - press configure, next - enable option "build examples", press configure second time, press generate...
It's all. Now open project opencv, find traincascade subproject and build it:)
There are some files in the archive. E.g. cascadeclassifier.cpp (CPU and GPU in the samples folder and the source in opencv/modules) and traincascade.cpp.
There is also this guide. I've heard that training is a bit difficult. If you come with a complete answer, feel free to share it.
Related
Problem
I've been developing a game in C++ in my spare time and I've opted to use Bazel as my build tool since I have never had a ton of luck (or fun) working with make or cmake. I also have dependencies in other languages (python for some of the high level scripting). I'm using glfw for basic window handling and high level graphics support and that works well enough but now comes the problem. I'm uncertain on how I should handle dependencies like glfw in a Bazel world.
For some of my dependencies (like gtest and fruit) I can just reference them in my WORKSPACE file and Bazel handles them automagically but glfw hasn't adopted Bazel. So all of this leads me to ask, what should I do about dependencies that don't use Bazel inside a Bazel project?
Current approach
For many of the simpler dependencies I have, I simply created a new_git_repository entry in my WORKSPACE file and created a BUILD file for the library. This works great until you get to really complicated libraries like glfw that have a number of dependencies on their own.
When building glfw for a Linux machine running X11 you now have a dependency on X11 which would mean adding X11 to my Bazel setup. X11 Comes with its own set of dependencies (the X11 libraries like X11Cursor) and so on.
glfw also tries to provide basic joystick support which is provided by default in Linux which is great! Except that this is provided by the kernel which means that the kernel is also a dependency of my project. Now I shouldn't need anything more than the kernel headers this still seems like a lot to bring in.
Alternative Options
The reason I took the approach I've taken so far is to make the dependencies required to spin up a machine that can successfully build my game very minimal. In theory they just need a C/C++ compiler, Java 8, and Bazel and they're off to the races. This is great since it also means I can create a Docker container that has Bazel installed and do CI/CD really easily.
I could sacrifice this ease and just say that you need to have libraries like glfw installed before attempting to compile the game but that brings the whole which version is installed and how is it all configured problem back up that Bazel is supposed to help solve.
Surely there is a simpler solution and I'm overthinking this?
If the glfw project has no BUILD files, then you have the following options:
Build glfw inside a genrule.
If glfw supports some other build system like make, you could create a genrule that runs the tool. This approach has obvious drawbacks, like the not-to-be-underestimated impracticality of having to declare all inputs of that genrule, but it'd be the simplest way of Bazel'izing glfw.
Pre-build glfw.o and check it into your source tree.
You can create a cc_library rule for it, and put the .o file in the srcs. Even though this solution is the least flexible of all because you not only restrict the target platform to whatever the .o was built for, but also make it harder to reproduce the whole build, the benefits are sometimes worth the costs.
I view this approach as a last resort. Even in Bazel's own source code there's one cc_library.srcs that includes a raw object file, because it was worth it, as the commit message of 92caf38 explains.
Require that glfw be installed.
You already considered this option. Some people may prefer this to the other approaches.
I want to use just 4 from the OpenCV libraries, and I have build it all on my computer, but on the other one, I want to build just the 4 of them. Is there a way to do it with CMake? Shall I modify the OpenCVConfig.cmake file? If yes, how?
Or to be more precisely, the question is:
How to build the OpenCVs libraries one by one? using Linux
So I really cant understand how this work but late me explain. First, just in case you need it, I am running Ubuntu 12.04 64-bit on a laptop.
As a building tool am using CMake. I want to load in to my project OpenCV, MRPT (http://www.mrpt.org/) and libfreenect. All of them have a "source code". What I don't understand is when they say "build from source". How to I make a project with all of them?
Do I need to build each one individually and with some way but then in my project OR do I down load the source code and build them all together at ones? As you can see I'm really confused what I have to do... do I run the CMakeList.txt from each source code and the run one CMakeList.txt that has all the other CMakeList.txt?
In fewer world, if I want to build from source, two or more libraries, how do I do that?
I would like a general answer (how this "build from source" works) and an answer specifically on the the ones I mentioned (CMake, OpenCV, MRPT, libfreenect). I hope I made clear what I don't really understand.
It depends of the 'master' project. In general in the c/c++ universe your project must know how to invoke the build process of each subproject/library OR your project needs to know how to include&link the results after building each external project yourself.
You can also mix the two approaches if needed but I think it cleaner to try to use one if possible.
In the first case if all the subprojects offer cmake building files (CMakeLists.txt) you may try to add_subdirectory() each and see if there are any conflicts. For example google test can be easily included this way and it gives your project some global variables that easy linking later.
Alternatively or if the above approach gives problems or the sub project doesn't provide CMakeLists.txt you can use ExternalProject_add(). It takes more work and you have to handle includes/linking configurations with your project manually but it makes the subproject more independent. For example if there are conflicting targets with your project or the subproject doesn't provide CMakeLists.txt.
The last approach involves building and installing the sub projects separately, using configuration variables in your project to point the includes/libraries paths of the sub project. Check CMake:How To Find Libraries for details.
I want to open libraries, because currently I want to see the algorithms used for drawing, modify them and implement them in my program. For example: I have tried to create an algorithm on my own for lines. But I failed. And even if I had succeeded, I fear that it might not give the same result as the algorithm in the libraries. And I don't want this to happen. That's why I want to copy the algorithms used for the methods in libraries. And I really hope that this will help me create the application I'm currently working on and with other applications in the future.
I tried to open the libraries with a code editor. But I had troubles finding the libraries- I don't really know where are they placed nor in what files are their codes stored.
How to open a Java library? Or is there a place in the Internet where the code is uploaded?
It sounds like what you want is to get inside the standard Java libraries (so you can see the code for methods like Graphics.drawLine()).
You can download the source files from the same place you got the JDK, if you are on Windows or Linux. For the Mac, see this question. You can even set up Eclipse so that you can debug into that source as if it were your own code.
However, you will probably not find line-drawing code in Java in these libraries - the Graphics implementation will almost certainly use native methods, and may just call existing methods in the OS.
If you are specifically looking for line drawing algorithms, another option would be to look at the Wikipedia page for the Bresenham (aliased) or Wu (antialiased) algorithm.
Edit:
The part of a Graphics2D call that actually puts pixels on the screen is probably inside a system call and therefore the source would not be available.
A java vector graphics library like Batik might have source for some of these algorithms, but probably relies on the Graphics2D calls for most of them. So, you might look for a comprehensive vector graphics library written in a language other than Java, where those graphics calls do not already exist by default.
Alternately, checking the table of contents for a computer graphics book might point you at a variety of algorithms that you could look up on Wikipedia.
For any given library:
Make sure to obey all licenses when using another's code
If you are referring to the Java SDK source code, you can find it here: http://grepcode.com/
If the project is open source, you can usually just get the source from the project website. No problem, though make sure to obey their license.
If the project is NOT open source, well, then you're in a pickle licensing wise, so I do NOT endorse this, however, you would need to use a Java Decompiler such as JD-Gui
As far as what drawing algorithms to use, there are so many different ones (obviously, people have been trying to draw quickly for many many years), your best bet is to figure out exactly what you need to do and then search for that specific need separately. There isn't really a good repository of ALL of them, except maybe wikipedia.
If you are using the libraries they are on your classpath. Check out how to figure out your classpath in whichever IDE you are using and you can find the JARs you depend on. If they are packaged with sources all you need to do it unjar them and look at the sources.
If you don't have access to the sources you can get the code using a Java Decompiler.
If you are trying to look at a standard Java library, see the other answers about getting the source to the JDK.
If you are interested in an open source library (such as something maintained by the Apache project), look on the site of the project for a 'source jar' which you can open with a standard zip utility.
If the library you want is not open source or you cannot find the source for it, you can try to decompile it. If you are using Eclipse, try this decompiler.
I am working on a project where I have to detect the features of an object (in a Video Frame) and match it with other objects (inside some other frame) to recognize the same object for tracking. I have googled many Feature detector algorithms. I also did some comparisons between them (SIFT,SURF & ASIFT).
ASIFT is computationally a bit expensive but the results are more accurate when compared to SIFT & SURF.
I have googled a lot about ASIFT but did not get any success regarding my project.
Can someone please help me with using ASIFT in my project?
ASIFT reference:
http://www.ipol.im/pub/algo/my_affine_sift/
Which files should I include in my project? I'm working on OPENCV 2.1 , IDE VS 2010.
Its my first post on this platform. Hope some one will help me.
The important functions are in the files compute_asift_keypoints.{c,h} and compute_asift_matches.{c,h}. They will inform you about which functions are mandatory. From there you have the choice:
Quick-and-dirty way:
you need to include and compile everything, except the executable part (file demo_*.cpp). You can either compile the files as a library (by modifying the CMakeLists.txt) or add them to your project in your IDE. Note that you will not use the functions from io_png for example, but you need to compile them if you don't want to be annoyed by compiler errors about missing functions.
Clean (but longer) way:
you have to ignore / remove all the files that also contain the I/O part, since OpenCV can take care of them. Then you can also look for functions that are already implemented in OpenCV, such as applying an affine transform, SVD... and progressively replace them by their OpenCV counterpart.