Both Fujifilm Z900EXR and Canon ELPH 340 HS have 16.0 MP resolution sensors but Fujifilm Z900EXR's sensor is 1/2-inch (6.4 x 4.8 mm ) and Canon ELPH 340 HS's sensor is 1/2.3-inch (6.17 x 4.55 mm ).
Since Fujifilm Z900EXR'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 Canon ELPH 340 HS.
Below you can see the Z900EXR and ELPH 340 HS sensor size comparison.
Fujifilm Z900EXR 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.