Casio EX-FC100 has a 9.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CMOS sensor . On the other hand, Canon SX510 HS has a 12.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CMOS sensor and features Digic 4 processor.
Below you can see the EX-FC100 and SX510 HS sensor size comparison.
Casio EX-FC100 and Canon SX510 HS have sensor sizes so they will provide same level of control over the depth of field when used with same focal length and aperture. On the other hand, since Casio EX-FC100 has 77% larger pixel area compared to Canon SX510 HS, it has potential to collect more light on pixel level hence have less noise in low light / High ISO images.