Fujifilm X-T1 IR has a 16.0MP APS-C (23.6 x 15.6 mm ) sized CMOS X-TRANS II sensor and features EXR Processor II processor. On the other hand, Samsung Galaxy NX has a 20.0MP APS-C (23.5 x 15.7 mm ) sized CMOS sensor and features DRIMe IV processor.
Another difference between these two cameras is that Fujifilm X-T1 IR's sensor lacks anti-alias (Low-Pass) filter. Removing anti-alias filter increases the sharpness and level of detail but at the same time, it increases the chance of moire occurring in certain scenes.
Below you can see the X-T1 IR and Galaxy NX sensor size comparison.
Fujifilm X-T1 IR and Samsung Galaxy NX have almost the same sensor size so none of them has any significant advantage over other in providing control over depth of field when used with same focal length and aperture.