Patent ID: 7151859
Filing Date: 2006-12-19
Classification: G06K

Abstract:
1. A method of detecting the direction of a document image, comprising the steps of: inputting the document image in original multi-value data; determining whether the document image has been reversed in brightness, said determining step further comprises the following steps of: digitizing the multi-value data into digitized image data; extracting a first set of minimal circumscribing rectangles containing continuous black pixels from the digitized image data; counting a first number of black pixels in the first set of the extracted minimal circumscribing rectangles; reversing brightness of the original multi-value data into brightness reversed image data; digitizing the brightness reversed image data into digitized brightness reversed image data; extracting a second set of minimal circumscribing rectangles containing continuous black pixels from the digitized brightness reversed image data; counting a second number of black pixels in the second set of the extracted minimal circumscribing rectangles; and determining the brightness reversal based upon the first number and the second number; and in case that the document image has not been reversed in brightness, digitizing the multi-value data into digitized image data; and detecting the direction of the document image based upon the digitized image data; or in case that the document image has been reversed in brightness, reversing brightness of the original multi-value data into brightness reversed image data; digitizing the brightness reversed image data into digitized brightness reversed image data; and detecting the direction of the document image based upon the digitized brightness reversed image data.