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, Casio EX-ZR100 has a
12.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized BSI-CMOS sensor and features Exilim Engine HS processor.
Below you can see the SX120 IS and EX-ZR100 sensor size comparison.
As seen above, Casio EX-ZR100 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.