I have seen twain module for Python2, is there anything similar for Python3?
I need to control scanning process and, specifically, histogram settings (shadow, highlight, gamma), resolution and scanning window size. What would be the best way to automate it in Python3?
EDIT: If not in Python, are there any C/C++ libraries which could be integrated into Python and control scanning process? I know only one library, EZTwain, it supports multiple programming languages (excluding Python) but it didn't work for some histogram settings and there was no support even for commercial version, so I would avoid using it.
We use a third-party toolkit named leadtools that might help you. This toolkit supports the most common programming languages including C/C++, C#, VB.NET and so more. For more information, you can check these 2 help topics:
For .NET:
Acquiring an Image using .NET
For C++:
Acquiring an Image using C++
Related
I have been working on a project where I am interacting with a 3D camera(on a single machine) through its SDK written in C++. The extent of my knowledge in that language is just as good as what a basic crash course could teach. I need to provide an interface(web) which shows the camera preview from the SDK and when the capture image is clicked, I need to capture an Image using the SDK with a specified filename and path.
The approaches I thought of are:
Using NodeJS exec to capture images the compiled version(exe) of my program in C++. I am communicating the filepath and using json.
I could learn and use C++ CGI to simply control C++ SDK stuff.
Any help/suggestions would be greatly appreciated. Thanks in advance.
You can use one of the C++ CGI libraries out there but, as easy as they are to use, just calling an executable seems easier and cleaner. I think the scanner should come with a bundled tool to drive it, doesn’t it?
Can I use OpenCV with Ruby on Rails? If so, how can I do that? Or, what resources do you recommend for that?
Thanks.
There is also an open CV gem, fwiw -- https://github.com/ruby-opencv/ruby-opencv.
Sure you can!
It just depends on what do you need as there is no "one" silver bullet.
If you want to create an online home surveillance, for example, then you would probably have least effort by writing:
C++ image-processing command-line application on top of OpenCV that would write the surveillance events and/or images to SQLite database.
Read the database directly from Rails.
For anything more complex, you'd need a more complex architecture.
Whatever you do, pick the best tools for the purpose:
Let OpenCV do what it is best at (image processing)
Let Rails to it's magic (simple, less demanding online access to some resources)
In order to link OpenCV and Ruby together, you could create a dedicated Ruby-to-C++ bridge because none of the existing ones can match diverse needs and most frameworks will do for a few specialized (i.e. designed by you) function-calls through your bridge.
This link would be a good start to pick a framework for a bridge - just go for one and see what comes out.
You could write a program using OpenCV in C++, and then just process your data with it, by using CGI (Common Gateway Interface http://en.wikipedia.org/wiki/Common_Gateway_Interface). I don't think you can bind native code to Ruby like you can do in Java (JNI)
It seems like most image processing apps are done using matlab or OpenCV using C++.
Are there any other languages providing good image processing libraries?? How do they compare to matlab and opencv?
When I say languages I mean something like Java , python or even perl!
Image libraries exist for many languages
Lisp:
ch-image
http://cyrusharmon.org/static/projects/ch-image/doc/ch-image.xhtml
Java:
ImageJ
http://rsbweb.nih.gov/ij/
OpenCV Java
http://ubaa.net/shared/processing/opencv/
Python:
Python Imaging Library
http://www.pythonware.com/products/pil/
ImageMagick offers binding for a large variety of languages: Ada C, Ch, COM+, C++, Java, Lisp, Pascal, Php, Perl, Ruby ...
But the main point is that image processing requires very good performance. A typical image contains millions of points to process. The efficiency issue is even more critical for 3d images, which are very common in medical imaging.
In practice, the main image processing libraries are written in C++ or have binding to C++.
You can take a look at this one Milena (offering python bindings). And here is a non exhaustive list of image processing libraries in C++ (each offering various binding for different languages or web services)
http://www.lrde.epita.fr/cgi-bin/twiki/view/Olena/SimilarProjects
For python:
PIL - Image Library
PyOpenCV
VTK
You can use Boost GIL(generic image library) for C++.
http://www.boost.org/doc/libs/1_44_0/libs/gil/doc/index.html
The Python Imaging Library is a very useful low-level library. You won't get C++-like performance with an interpreted language, but if that's not important, you should look at it.
Just about any language does. Google can help you here. Type in (language) image processing to see what libraries are available for whichever languages you're looking at. ImageMagick is one of the older and more well-known libraries that is usable from several different languages.
I want to write a C++ application with Qt, but build a prototype first using Python and then gradually replace the Python code with C++.
Is this the right approach, and what tools (bindings, binding generators, IDE) should I use?
Ideally, everything should be available in the Ubuntu repositories so I wouldn't have to worry about incompatible or old versions and have everything set up with a simple aptitude install.
Is there any comprehensive documentation about this process or do I have to learn every single component, and if yes, which ones?
Right now I have multiple choices to make:
Qt Creator, because of the nice auto completion and Qt integration.
Eclipse, as it offers support for both C++ and Python.
Eric (haven't used it yet)
Vim
PySide as it's working with CMake and Boost.Python, so theoretically it will make replacing python code easier.
PyQt as it's more widely used (more support) and is available as a Debian package.
Edit: As I will have to deploy the program to various computers, the C++-solution would require 1-5 files (the program and some library files if I'm linking it statically), using Python I'd have to build PyQt/PySide/SIP/whatever on every platform and explain how to install Python and everything else.
I want to write a C++ application with Qt, but build a prototype first using Python and then gradually replace the Python code with C++. Is this the right approach?
That depends on your goals. Having done both, I'd recommend you stay with Python wherever possible and reasonable. Although it takes a bit of discipline, it's very possible to write extremely large applications in Python. But, as you find hotspots and things that can be better handled in C++, you can certainly port relevant parts to C++.
Is there any comprehensive documentation about this process or do I have to learn every single component, and if yes, which ones?
Here's what I'd recommend for the various pieces:
EDITOR/IDE: Use any editor/IDE you're comfortable with, but I'd highly recommend one that supports refactoring. If you're comfortable with Eclipse, use it. If you want to mainly go the C++ route and you're not too familiar with any editors, you might be better off with QtCreator. Eric is an extremely good Python IDE with support for refactoring, unless you're going to be doing lots of C++, take a look at it. Even better, its source code is an example of good PyQt usage and practices.
PROCESS:
The quick summary:
Write your application in Python using PyQt
When identified as hotspots, convert decoupled Python classes to C++
Create bindings for those classes using SIP
Import the newly defined libraries in Python in place of their Python counterparts
Enjoy the speed boost
General details:
Write the application in Python using PyQt. Be careful to keep a good separation of concerns so that when you need to port pieces to C++ they will be separate from their dependencies. When you finally need to port something to C++, write it in C++/Qt and then create bindings for it using SIP. SIP has a good reference manual on the process, and you have all of PyQt as an example.
DEPLOYMENT:
C++ - For many applications the dependencies are sufficiently simple that it's not too difficult to create an installer using a tool like NullSoft's Installer or InnoSetup.
Python/PyQt - PyQt applications are a bit more difficult to install because of the dependency on Python and its dependence on the presence of the Qt libraries. One person documented his efforts on this post at ARSTechnica. py2exe works pretty well on Windows and should work fine. IME, freeze.py, which comes with the Python source, sometimes has problems determining which shared libraries are truly necessary and will sometimes end up creating a binary whose dependencies aren't present. Py2app can be made to work on Mac OS X.
But worse, however, is the PyQt/Qt licensing. If you are developing a commercial application, you need to have a commercial PyQt (and Qt) license and make sure to prevent the users from easily modifying the source or otherwise writing code against the PyQt/Qt API because of licensing restrictions. Because of that, the PyQt author created a tool called VendorId (although it has a Python license). Within VendorId is a tool called SIB that can be used to create an executable which depends only on the Python interpreter. But, if you're going to go this far, you might want to install a custom Python along with your application.
DISCLAIMER: I haven't used PySide at all, so I'm not sure how it compares to PyQt. Also, note the following warning on their website:
PySide is a work in progress and is not yet suited for application development requiring production-level stability.
But, on a good note, they intend, at least for the initial release to "maintain API compatibility with PyQt." So, aside from the C++ bindings, you could easily switch between the two later.
If you are just learning Qt and want to leverage the speed of prototyping that Python gives you, then I would recommend you make a sample project using PyQt. As you said, there is a debian package, so you are just a simple apt-get away from making your first application.
I personally use gVim as my Python/Qt editor, but you can really use any Python-friendly editor without much trouble. I liked WingIDE and they have auto-complete for Qt but once you sip from the vim kool-aid it's hard to switch.
I would say that PySide is 95%+ compatible with PyQt and the LPGL license is nice, but if you are just trying to prototype your first Qt app, then I don't think there is a real reason to use PySide. Although, I do like the PySide docs better, you can also just use them and replace all the library references with PyQt.
Depending on the complexity of the application you are building, it might be better off to just start from scratch with a C++ version than to try to do a bunch SIP refactoring black magic. Once you have a solid grasp of the Qt framework, you should be able to switch between the C++ and Python bindings pretty effortlessly.
I would draw UI mockups before starting to code prototypes. Here are some benefits:
Quicker than coding prototypes as there is no programming involved
Quickly fill widgets, such as tables and trees, with data
Add descriptions and notes to your screens
Easily integrate mockups into specification documents without having to capture screens
Validate UI design concepts before implementing
There are a lot of tools that can help you do that, but if you are going to use Qt, MockupUI may be a good choice as it renders Qt widgets with native styles for Windows 7,8 or 10 which makes your mockup look more realistic.
We are developing a rather large project in C++, where many components require configuration parameters. We would like to use a central place to configure everything (like a registry), preferably with a nice and simple GUI (e.g. like Firefox's about:config) and a simple API.
I am pretty sure this that many applications have this kind of problem, but could not find any libraries available that can be readily used for this. Does anyone know of a good (preferably free) library to use for this?
This should work cross platform in Windows and Linux.
boost::program_options provides unified (and cross platform) support for configuration from command line, environment variables and configuration files. It seems like it ought to scale to multiple bits of a large software system registering an interest in various parameters (e.g option groups). Not much help with the GUI or persistence side of things though (but then what's wrong with editing a config file with a text editor ?).
I've used libconfig before, works well easy and LGPL.
http://www.hyperrealm.com/libconfig/
I've used a modified version of John Torjo code from TechRepublic/DDJ (source)
The multi platform ACE library has a configuration class that uses config files that have the Windows .ini format.
I've often used a simple wrapper around pugxml. I find that creating a configuration class with parameter validation for enumerated types and so on makes the rest of the code much cleaner. If you are just dealing with key/value pairs you will have to validate the data all throughout your code. By writing a custom class for each application you can put all that in one place.
Try Configurator. There is no GUI, but it's easy-to-use and flexible C++ library for configuration file parsing (from simplest INI to complex files with arbitrary nesting and semantic checking). Header-only and cross-platform. Uses Boost C++ libraries.
See: http://opensource.dshevchenko.biz/configurator