Ricoh WG-6 has a 20.0MP 1/2.3" (6.17 x 4.55 mm ) sized BSI-CMOS sensor . On the other hand, Olympus E-620 has a 12.0MP Four Thirds (17.3 x 13 mm ) sized CMOS sensor and features TruePic III+ processor.
Ricoh WG-6's sensor provides 8MP more than Olympus E-620'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 WG-6 and E-620 sensor size comparison.
![Ricoh WG-6 vs Olympus E-620 Sensor Size Comparison]()
Sensor Size and Resolution Comparison image of Ricoh WG-6 and Olympus E-620 Cameras
As seen above, Olympus E-620 has a 8.0x Larger sensor area than Ricoh WG-6. Larger sensors give photographer more control on the depth of field and blurry background compared to smaller sensor when shot in same focal length and aperture.