Samsung ST600 has a
14.0MP 1/2.3-inch (6.08 x 4.56 mm ) sized CCD sensor . On the other hand, Canon S100 has a
12.0MP 1/1.7-inch (7.44 x 5.58 mm ) sized CMOS sensor and features Digic 5 processor.
Below you can see the ST600 and S100 sensor size comparison.
As seen above, Canon S100 has a 1.5x Larger sensor area than Samsung ST600. 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.