Fujifilm X20 has a
12.0MP 2/3-inch (8.8 x 6.6 mm ) sized CMOS X-TRANS II sensor and features EXR Processor II processor. On the other hand, Canon A3000 IS has a
10.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor .
Below you can see the X20 and A3000 IS sensor size comparison.
As seen above, Fujifilm X20 has a 2.1x Larger sensor area than Canon A3000 IS. 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.