The preference setting as shown in the screen capture will allow the file size shown in pixel dimensions.
The number of XY pixels is shown everywhere if desired or not. I know that.
However "Original Size" is a virtual/arbitrary size in imperial or metric units that Photoshop allows you to set in the Image Size menu and Qimage Ultimate can read that size from a PS exported Tiff or Jpeg when "Original Size" is used to set a print size for that image. So Qimage Ultimate already can read it but does not display it other than in the print page queue as I already mentioned.
It is way easier for me when customers send me images with that "Original Size" set. They do not have to resample the image in PS either to add that size, the available pixels are just scaling to the cms/inches when the size is set and the resample function is off.
I would not mind if if the "Original Size" is shown in the image editor too or more desirable; a crop made there displayed in mm calculated from that information.
Met vriendelijke groet, Ernst
http://www.pigment-print.com/spectralplots/spectrumviz_1.htmNovember 2014 update, 680+ inkjet media white spectral plots