Canon SX10 IS has a
10.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor . On the other hand, Sony HX80 has a
18.0MP (1/2. ) sized BSI-CMOS sensor and features Bionz X processor.
Sony HX80's sensor provides 8MP more than Canon SX10 IS'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 SX10 IS and HX80 sensor size comparison.
As seen above, Canon SX10 IS has a infx Larger sensor area than Sony HX80. 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.