Canon G9 X has a
20.0MP 1″ (13.2 x 8.8 mm ) sized BSI-CMOS sensor and features DIGIC 6 processor. On the other hand, Casio EX-ZR800 has a
16.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CMOS sensor and features EXILIM Engine HS 3 processor.
Below you can see the G9 X and EX-ZR800 sensor size comparison.
As seen above, Canon G9 X has a 4.1x Larger sensor area than Casio EX-ZR800. 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.