[PLUG] Concatenating two square icons to get single rectangular image

[Richard Owlett]

Consider two 48x48 icons. I wish a single 48x96 icon.
I've already looked at Gimp and ImageMagick.
They are OVERkill.
Like using LaTex to concatenate two 10 character strings.
Would prefer png abut either bmp or jpeg would also work.
TIA