Casio EX-FH25 has a 10.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized BSI-CMOS sensor . On the other hand, Canon G3 X has a 20.0MP 1' (13.2 x 8.8 mm ) sized BSI-CMOS sensor and features DIGIC 6 processor.
Canon G3 X's sensor provides 10MP more than Casio EX-FH25's sensor, which gives a significant advantage in real life. You can print your images larger or crop more freely.
On the other hand, please keep in mind that Max sensor resolution is not the only determinant of resolving power. Factors such as the optical elements, low pass filter, pixel size and sensor technology also affects the final resolution of the captured image.
Below you can see the EX-FH25 and G3 X sensor size comparison.
![Casio EX-FH25 vs Canon G3 X Sensor Size Comparison]()
Sensor Size and Resolution Comparison image of Casio EX-FH25 and Canon G3 X Cameras
As seen above, Canon G3 X has a 4.1x Larger sensor area than Casio EX-FH25. 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.