Canon G16 has a 12.0MP 1/1.7" (7.44 x 5.58 mm ) sized BSI-CMOS sensor and features Digic 6 processor. On the other hand, Pentax WS80 has a 10.0MP 1/2.3" (6.17 x 4.55 mm ) sized CCD sensor and features Prime processor.
Below you can see the G16 and WS80 sensor size comparison.
As seen above, Canon G16 has a 1.5x Larger sensor area than Pentax WS80. 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.