Patent ID: 6519362
Filing Date: 2003-02-11
Classification: G06K

Abstract:
A method of extracting text from a color image, comprising the steps of:a) receiving a color image, where the image includes pixels, where each pixel is represented by a color component system; b) converting the color image received to at least one grayscale image using a conversion method selected from the group of conversion methods consisting of the following: C1ij=avg(Rij, Gij), C2ij=avg(Rij, Gij, Bij)/avg(Rij, Gij, Bij), C3ij=min(Rij, Gij, Bij)/max(Rij, Gij, Bij), C4nij=one(Rij, Gij, Bij)/another(Rij, Gij, Bij), C5nij=sumcomb(Rij, Gij, Bij)/sum(Rij, Gij, Bij), and â€ƒany combination thereof, where Cmnij is the value of each color component of a pixel ij in the at least one grayscale image, where avg returns an average, where Rij is a value of a red color component of a corresponding pixel ij in the received image, where Gij is a value of a green color component of the corresponding pixel ij in the received image, where Bij is a value of a blue color component of the corresponding pixel ij in the received image, where min returns a minimum, where max returns a maximum, where one returns one value, where another returns a value other than the one returned by one, where sumcomb returns a sum of less than all values, where sum returns a sum, and where n=1, 2, 3, 4, 5, and 6,; and c) comparing, for each pixel in the at least one grayscale image resulting from step (b), the color component value of the pixel in the at least one grayscale image to a user-definable threshold T and setting the pixel in the at least one grayscale image to a first value if the color component value of the pixel in the at least one grayscale image is not greater than T, otherwise setting the pixel in the at least one grayscale image to a second value.