Both Casio EX-100 and Panasonic TS1 have 12.0 MP resolution sensors but Casio EX-100's sensor is 1/1.7-inch (7.44 x 5.58 mm ) and Panasonic TS1's sensor is 1/2.3-inch (6.08 x 4.56 mm ).
Since Casio EX-100's has a larger sensor area with the same resolution, this means that it also has a larger pixel area hence better light collecting capacity for a given aperture compared to Panasonic TS1.
Below you can see the EX-100 and TS1 sensor size comparison.
As seen above, Casio EX-100 has a 1.5x Larger sensor area than Panasonic TS1. 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.