Samsung HZ25W has a
12.0MP 1/2.3-inch (6.08 x 4.56 mm ) sized CCD sensor . On the other hand, Leica V-Lux 2 has a
14.0MP 1/2.3-inch (6.08 x 4.56 mm ) sized CMOS sensor .
Below you can see the HZ25W and V-Lux 2 sensor size comparison.
Samsung HZ25W and Leica V-Lux 2 have the same 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 Samsung HZ25W has 16% larger pixel area compared to Leica V-Lux 2, it has potential to collect more light on pixel level hence have less noise in low light / High ISO images.