Tormod Landet

Sorting images

Once upon a time, back when I was using Windows at home, I had a useful small program that helped me sort through new pictures from my camera. I have forgotten the name of the program, but basically it allowed me to sort the good pictures from the bad in a fast and efficient manner so that the really bad ones could be deleted and the good ones could be separated, maybe for sharing with others.

I have just been on a trip where I took quite some pictures. I could have gone over the pictures and manually copied the good ones into a separate folder for sharing with friends. This would have been a bit boring, but it would only have taken about five minutes. As a programmer I of course selected to optimize this task and spent some hours recreating the program I had once used. After a thousand trips or so I will come out ahead in terms of time spent!

The program looks like this:

Picster GUI

I named it Picster, short for Picture Sorter. There is, of course, at least one other programs with that name already, but I cannot be bothered to find something better at the moment, It's just a script, after all. It is meant to be used from the keyboard, but there are also buttons for all possible actions (moving between images, categorizing images, and sorting images on disk based on category information).

All of the GUI coding I do at work is scientific visualization, mostly using Python 2 and the wx library in some way. To try something slightly different I went with Python 3 and Qt for this program. I cannot really call myself an expert in Qt after only a couple of hours and the Picster code is probably not how a Qt expert would have written it, but it seems to work OK.

From this brief encounter, Python Qt code seems to be a bit more verbose and tedious compared to wxPython. For example Qt/PySide is missing the nice init arguments, so all properties on an object must be set after creation through method calls. The API is not very pythonic with no use of Python properties as far as I understood. I am also missing docstring help on class and method name completion in Eclipse PyDev :-(

Also missing as far as I understood is the wxPython ability to bind to any event from anywhere. To listen for keystrokes or window size change for example you must override virtual methods. For now I am happy with using wx at work. The Qt documentation that was rumored to be fabulous seems quite on the same level of the wx documentation as well.

What I really liked about Qt was the Layouts which work almost exactly like Sizers in wx, except that they come with a sensible default spacing of widgets. This is a sore spot in laying out wx interfaces and always needs manual intervention to look good.

Enough mostly unqualified statements about Qt vs. wx, here's the code for anyone interested in a picture sorting program. The code requires Python (probably works in versions 2 and 3, tested in 3.2) and PySide for Python bindings to Qt.


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