1. A method for removing noise from an image, comprising: performing, by a computer: receiving the image; analyzing the image, comprising: identifying a text region within the image; identifying one or more key characters within the text region, wherein a key character is a character or a portion of a character; locating a plurality of blobs within the image, wherein a blob is a cluster of adjacent pixels which possibly represent a character or part of a character within the image; computing a noise threshold based on a size of the one or more key characters within the text region, wherein blobs of the plurality of blobs that are smaller than said noise threshold are likely to be noise; and removing from the image one or more of the plurality of blobs which are smaller than said noise threshold.