Canon SX130 IS has a
12.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor and features Digic 4 processor. On the other hand, Canon SX160 IS has a
16.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor and features Digic 4 processor.
Below you can see the SX130 IS and SX160 IS sensor size comparison.
Canon SX130 IS and Canon SX160 IS 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. On the other hand, since Canon SX130 IS has 32% larger pixel area compared to Canon SX160 IS, it has potential to collect more light on pixel level hence have less noise in low light / High ISO images.