Version:           1.7.0 (using KDE 4.6.3) 
OS:                Linux

The user may want to increase of decrease image resolution for multiple purpouses. For example, for print I may want to convert a large image (30 x 40 cm) with low resolution (96 ppi) into a higher resolution image (300 ppi), either maintaining original image dimensions (through interpolation) or resizing it accordingly. You can do it easily and intuitively in apps like Photoshop or The Gimp via the "image size" dialog. By contrast, in showfoto there's an option to resize, but the user can't change image resolution there. In digikam proper, there's a batch resize tool, which lets the user prepare images for print. But it has some problems: 1) the option it's too hidden; 2) the user doesn't see any data about image size and resolution before applying the batch action: you don't even know if you're applying the right aspect ratio! It is a very basic operation in most people's workflow and one should not need to leave digikam and open the Gimp to do such a simple action. I love showfoto, and this is the only thing I am really missing!

Reproducible: Always

Steps to Reproduce:
Just open the resize image option in showfoto.

Actual Results:  
 You don't see any clear way to change image resolution.

Expected Results:  
It should show you image size in pixels, image dimensions (in inches/cm, etc.) and image resolution (in ppi), together with a "interpolation" option disabled by default. It should behave in a way that modifications in image resolution proportionally affect image dimensions, and viceversa, unless the interpolation option is checked. Just look at the Gimp and Photoshop, please.