Sony WX70 has a
16.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized BSI-CMOS sensor and features BIONZ processor. On the other hand, Casio EX-H20G has a
14.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor and features Exilim Engine HS processor.
Below you can see the WX70 and EX-H20G sensor size comparison.
Sony WX70 and Casio EX-H20G have the same 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-H20G has 14% larger pixel area (2.01µm2 vs 1.76µm2) compared to Sony WX70, it has larger pixel area to collect light hence potential to have less noise in low light / High ISO images.