Canon A490 has a
10.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor . On the other hand, Olympus XZ-10 has a
12.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized BSI-CMOS sensor .
Below you can see the A490 and XZ-10 sensor size comparison.
Canon A490 and Olympus XZ-10 have the same sensor sizes so they will provide same level of control over the depth of field when used with same focal length and aperture.