Samsung ST600 has a
14.0MP 1/2.3-inch (6.08 x 4.56 mm ) sized CCD sensor . On the other hand, Canon ELPH 340 HS has a
16.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CMOS sensor and features DIGIC 4+ processor.
Below you can see the ST600 and ELPH 340 HS sensor size comparison.
Samsung ST600 and Canon ELPH 340 HS have almost the same sensor size, so neither of them has any significant advantage over the other in terms of providing control over depth of field when used with the same focal length and aperture.