Hi
I was so pleased to discover Digikam running under windows - not my preferred platform but I do have to use Windows.
I'm using the Windows 7 64bit platform.
I first downloaded vers 3.4.0 and it installed fine but the Tools/Resize Images failed on everything I tried (single images and batch). I then discovered that there was a vers 4.2.0 which I now have running and the resize still does not work.
I normally run Digikam on my home Suse 13.1 Linux platform and love the editor.
I have tried both proportional and non-proportional settings and it fails every image.
This is a result using Proportional (1 dim) with 640 size set.

convert -resize 640x640 -filter Bessel -quality 75 -verbose C:/Users/GarthDesktop/Desktop/MyPictures/Geelong 8Aug2014 night/Half Size/DSC_0259.png[0] C:/Users/GarthDesktop/Desktop/MyPictures/Geelong 8Aug2014 night/Half Size//DSC_0259_1.png

Invalid Parameter - 640x640

It seems to me that it hasn't figued out the sizing of the other dimension (eg 480 or whatever).

If I choose the Proportional (2dim) it fails with this error:

convert -verbose C:/Users/GarthDesktop/Desktop/MyPictures/Geelong 8Aug2014 night/DSC_0259.JPG[0] -resize 800x600 -quality 75 -profile C:/Users/GarthDesktop/Desktop/MyPictures/Geelong 8Aug2014 night/DSC_0259.JPG C:/Users/GarthDesktop/Desktop/MyPictures/Geelong 8Aug2014 night/Half Size//DSC_0259.JPG

Invalid Parameter - "C:

I have looked through the Configuration setup for the Edit functions and can't see anything I need to set. In Linux there is nothing to do - the resize just works :-)
I have also tried the Batch Queue manager and that does work - just a long winded way of resizing.