Canon SX120 IS has a 10.0MP 1/2.5-inch (5.744 x 4.308 mm ) sized CCD sensor and features Digic 4 processor. On the other hand, Panasonic FP2 has a 14.0MP 1/2.3-inch (6.08 x 4.56 mm ) sized CCD sensor and features Venus Engine IV processor.
Below you can see the SX120 IS and FP2 sensor size comparison.
As seen above, Panasonic FP2 has a 1.1x Larger sensor area than Canon SX120 IS. Larger sensors give photographer more control on the depth of field and blurry background compared to smaller sensor when shot in same focal length and aperture.