Image Processing and WxWidgets

Introduction

This project is my attempt to blend OpenCV and WxWidgets to re-learn Image Processing and at the same time, get more proficient on both libs.

There is another project I have here that shares the same code, but uses python, as a sort of make, to build C++ sources:

• https://github.com/zlogdanbr/images

When I was in college I had a, hmm, I have no idea if this exists in USA or UK or outside of Brazil. Basically, I was paid to do a research while being an undergraduate student.

So, my research was in Image Processing, especifically for x-ray scans of mamographies.

My major was Electrical Engineering - electronics- but I did and I still don't like it.

• Because of this research I learned Delphi and C.
• I had access to the internet ( around 1996-1998 )
• I used a lot of IRC.
• I was part of many mailing lists.

So, you can tell that besides all the math I learned, boolean logics, pascal and assembly, I own my career in great part to this.

Image Processing uses a lot of Math and discrete math. If I won the lottery, I would probably spend my time doing a master degree in Computer Vision.

Back to reality however, this is how I have fun. It is mostly a hobby project just like some people do carpentry or gardening.

Back in 1996 I had no idea if OpenCV existed or about libraries.

** WARNING ** The algorithms for face detection are not working. I have no idea why or how. I am running Windows 11, maybe that is it. I have removed them from the code.

Bulding for Linux

• Make sure you install OpenCV and wxWidgets

I suggest building wxWidgets from scratch, as explained here.

https://wiki.wxwidgets.org/Compiling_and_getting_started

This is a CMakeList.txt file that works:

cmake_minimum_required(VERSION 3.20)
project(diMage)
find_package(wxWidgets REQUIRED gl core base OPTIONAL_COMPONENTS net)
include(${wxWidgets_USE_FILE})
find_package( OpenCV REQUIRED )
include_directories( ${OpenCV_INCLUDE_DIRS} )
add_executable(diMage ../main.cpp ../childframes.cpp ../filesys.cpp ../image_algorithms.cpp ../image_gridialog.cpp ../image_helper.cpp ../image_io.cpp ../image_slide.cpp ../image_util.cpp ../mainframe.cpp ../opcvwrapper.cpp ../savekernel.cpp)
target_link_libraries(diMage PRIVATE ${wxWidgets_LIBRARIES} ${OpenCV_LIBS})

• Create a folder under the root folder of the project and create a CMakeList.txt file there.
• cmake .
• make

And that will do.

Tips

Adding new algorithms

The menu Algorithms->Basic Algorithms Selection allows you to choose between several algorithms.

So, edit the sources opcvwrapper.h and opcvwrapper.cpp adding a function with the signature cv::Mat foo( cv::Mat& m ).

Do all your processing inside this function then at childframe add the following:

void fillFSimple()
{
    fsimple["my foo"] = foo;
    comboBox1->Append("my foo");
}

Now the menu Algorithms->Basic Algorithms Selection contains foo.

Image format

I am working with jpg/tif input images and only jpg only for the output, but I plan to add options for more formats. Actually you can change that option only by changing these lines:

 void MyFrame::OnOpen(wxCommandEvent& event)
 
 wxFileDialog openFileDialog(this,
 	wxEmptyString,
 	wxEmptyString,
 	wxEmptyString,
 	"Image files (*.jpg)|*.jpg|All Files (*.*)|*.*",
 	wxFD_OPEN | wxFD_FILE_MUST_EXIST);
 
 and 

 void MyFrame::OnSave(wxCommandEvent& event)
 
    if (ImageHelper.getOriginalImageInitiated() == true)
    {
        auto name_final = ImageHelper.getOriginalImage().GetName();
        auto path = ImageHelper.getOriginalImage().GetPath();
        auto tosave = path + "\\" + name_final + "_proc_" + ".jpg";

Dependecies

wxWidgets:

https://wxwidgets.org

OpenCV:

https://opencv.org

The excellent graphics libs:

https://github.com/Profactor/cv-plot

https://alandefreitas.github.io/matplotplusplus/

Tools used

• I use Visual Studio 2022
• c++17
• OpenCV 4.8
• wxWdigets 3.2.1
• wxFormBuilder. Get it at https://github.com/wxFormBuilder/wxFormBuilder
• https://github.com/Profactor/cv-plot
• https://alandefreitas.github.io/matplotplusplus/

Python soon will be required.

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References:

• https://www.ogemarques.com/wp-content/uploads/2014/11/pdi99.pdf
• https://www.imageprocessingplace.com
• https://www.codtronic.com/blog/windows/building-wxwidgets-applications-using-microsoft-visual-studio/
• https://zetcode.com/gui/wxwidgets/
• https://wiki.wxwidgets.org/Avoiding_Memory_Leaks
• https://github.com/gammasoft71/Examples_wxWidgets
• https://github.com/gammasoft71/Examples_wxWidgets/blob/master/src/MenusAndToolbars/MainMenu/MainMenu.cpp
• https://www.developpez.net/forums/d1491398/c-cpp/bibliotheques/wxwidgets/opencv-transformer-cv-mat-wximage/
• https://stackoverflow.com/questions/8177747/converting-images-between-opencv-and-wxwidgets

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2022, 2023 Daniel Vasconcelos Gomes You can use this freely but I don't take responsibility for whatever problems this will likely cause.