Canon SX530 HS has a
16.0MP 1/2.3' (6.17 x 4.55 mm ) sized BSI-CMOS sensor and features DIGIC 4+ processor. On the other hand, Kodak Astro AZ651 has a
21.0MP (1/2. ) sized CMOS sensor .
Kodak Astro AZ651's sensor provides 5MP more than Canon SX530 HS'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 SX530 HS and Astro AZ651 sensor size comparison.
As seen above, Canon SX530 HS has a infx Larger sensor area than Kodak Astro AZ651. 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.