Image Processing Testbed project.
This is my first somewhat big Qt project.
The idea behind it is that it could probably be used by students to play with image processing in a somewhat engaging and easy way.
There are probably many things I could improve and I would appreciate any suggestions.
You can find the project here.
I just took a very quick look over your project. From a coding POV, there are indeed some things that can be cleaned e.g. there's usually no need to allocate QString on the heap, even if you pass it through signals and slots. QString is one of Qt's implicitly shared classes. Your usage of QSettings is also a bit unusual, you would usually allocate a QSettings object on the stack, get/store what you want and be done with it. You're not using QLatin1String (take also a look a QStringLiteral) in a consistent manner (e.g. listScriptsinDir)
One last thing is error handling, you should use an enum rather than a string. It makes it easier to react on e.g. using a switch statement. Since you have more complex error messages (as in constant message + dynamic information) then you could follow the QtSql module and have an error class which gives you both informations.
Hope it helps
As during development so and now your comments are very useful. I hope to fix the issues you pointed out as soon as I can.