1. An apparatus for feature detection of a test object, said apparatus comprising: at least one light source module for providing light to illuminate a test region of the test object, said light source module including a substrate, a set of light-emitting components mounted on said substrate for emitting light in parallel directions that are generally transverse to said substrate, and a light-focusing unit to be disposed between said light-emitting components and the test object, said light-focusing unit receiving the light emitted by said light-emitting components and focusing the light on the test region of the test object; and at least one image capturing unit for capturing an image of the test object at the test region.