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. On the other hand, Samsung SL720 has a
12.0MP 1/2.3-inch (6.08 x 4.56 mm ) sized CCD sensor .
Below you can see the ELPH 340 HS and SL720 sensor size comparison.
Canon ELPH 340 HS and Samsung SL720 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.