Casio EX-Z450 has a 12.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor . On the other hand, Samsung Galaxy Camera 2 has a 16.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized BSI-CMOS sensor and features 1.6GHz Quad-Core Exynos processor.
Below you can see the EX-Z450 and Galaxy Camera 2 sensor size comparison.
Casio EX-Z450 and Samsung Galaxy Camera 2 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-Z450 has 32% larger pixel area compared to Samsung Galaxy Camera 2, it has potential to collect more light on pixel level hence have less noise in low light / High ISO images.