1. A method for detecting a text region in an image, the method comprising: detecting a candidate text region from an input image; generating a set of oriented gradient images of the candidate text region; capturing one or more detection window images of the candidate text region; calculating a sum of oriented gradients for a region in one of the oriented gradient images; classifying whether each detection window image contains text by comparing the associated sum of oriented gradients and a threshold; and determining whether the candidate text region is a true text region based on the classifications of the detection window images.