Both Nikon L31 and Samsung WB30F have 16.0 MP resolution sensors but Nikon L31's sensor is 1/2.3' (6.17 x 4.55 mm ) and Samsung WB30F's sensor is 1/2.3-inch (6.17 x 4.55 mm ).
Since Samsung WB30F's has a larger sensor area with the same resolution, this means that it also has a larger pixel area hence better light collecting capacity for a given aperture compared to Nikon L31.
Below you can see the L31 and WB30F sensor size comparison.
Sensor Size and Resolution Comparison image of Nikon L31 and Samsung WB30F Cameras
Nikon L31 and Samsung WB30F 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.