Canon G9 X II has a 20.0MP 1″ (13.2 x 8.8 mm ) sized BSI-CMOS sensor and features DIGIC 7 processor. On the other hand, Olympus E-M10 has a 16.0MP Four Thirds (17.3 x 13 mm ) sized CMOS sensor and features TruePic VII processor.
Below you can see the G9 X II and E-M10 sensor size comparison.
As seen above, Olympus E-M10 has a 1.9x Larger sensor area than Canon G9 X II. 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.