Nikon S9100 has a
12.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized BSI-CMOS sensor and features Expeed C2 processor. On the other hand, Leica V-Lux 30 has a
14.0MP 1/2.3-inch (6.08 x 4.56 mm ) sized CMOS sensor and features Venus Engine FHD processor.
Below you can see the S9100 and V-Lux 30 sensor size comparison.
Nikon S9100 and Leica V-Lux 30 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.