Both Nikon S1000pj and Casio EX-10 have 12.0 MP resolution sensors but Nikon S1000pj's sensor is 1/2.3-inch (6.17 x 4.55 mm ) and Casio EX-10's sensor is 1/1.7-inch (7.44 x 5.58 mm ).
Since Casio EX-10'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 Nikon S1000pj.
Below you can see the S1000pj and EX-10 sensor size comparison.
As seen above, Casio EX-10 has a 1.5x Larger sensor area than Nikon S1000pj. 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.