Panasonic ZS100 has a 20.0MP 1" (13.2 x 8.8 mm ) sized MOS sensor and features Venus Engine processor. On the other hand, Canon G1 X III has a 24.0MP APS-C (22.3 x 14.9 mm ) sized CMOS sensor and features DIGIC 7 processor.
Below you can see the ZS100 and G1 X III sensor size comparison.
As seen above, Canon G1 X III has a 2.9x Larger sensor area than Panasonic ZS100. 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.