Canon ELPH 150 IS has a 20.0MP 1/2.3" (6.17 x 4.55 mm ) sized CCD sensor and features Digic 4+ processor. On the other hand, FujiFilm Z800EXR has a 12.0MP 1/2" (6.4 x 4.8 mm ) sized CCD sensor and features EXR processor.
Canon ELPH 150 IS's sensor provides 8MP more than FujiFilm Z800EXR's sensor, which gives a significant advantage in real life. You can print your images larger or crop more freely.
On the other hand, please keep in mind that Max sensor resolution is not the only determinant of resolving power. Factors such as the optical elements, low pass filter, pixel size and sensor technology also affects the final resolution of the captured image.
Below you can see the ELPH 150 IS and Z800EXR sensor size comparison.
![Canon ELPH 150 IS vs FujiFilm Z800EXR Sensor Size Comparison]()
Sensor Size and Resolution Comparison image of Canon ELPH 150 IS and FujiFilm Z800EXR Cameras
Canon ELPH 150 IS and FujiFilm Z800EXR have almost the same sensor size so none of them has any significant advantage over other in providing control over depth of field when used with same focal length and aperture.