Panasonic FX48 has a 12.0MP 1/2.3-inch (6.08 x 4.56 mm ) sized CCD sensor . On the other hand, Panasonic FP7 has a 16.0MP 1/2.3-inch (6.08 x 4.56 mm ) sized CCD sensor and features Venus Engine IV processor.
Below you can see the FX48 and FP7 sensor size comparison.
Panasonic FX48 and Panasonic FP7 have sensor sizes so they will provide same level of control over the depth of field when used with same focal length and aperture. On the other hand, since Panasonic FX48 has 32% larger pixel area compared to Panasonic FP7, it has potential to collect more light on pixel level hence have less noise in low light / High ISO images.