JP2511068B

PURPOSE:To obtain a device strong for a noise by providing a means for obtaining two binary pictures from a character part according to a floating threshold and a statistical processing and a means for detecting a horizontal line coordinate having high possibility in the appearance of a character string according to the correlation processing of the two binary pictures. CONSTITUTION:The moving average of the x direction (horizontal direction) of an original picture f(x, y) is obtained, subtracted from the origin 1 picture, thereby, a high frequency signal component DELTAf(x, y) is obtained. Then, the mean mu, a distribution sigma are obtained to the histogram of the DELTAf(x, y) taken in a proper area to obtain the binary pictures of a high brightness part and a low brightness part to the DELTAf(x, y) according to the equation I. The correlation calculation of the equation II is executed by H(x, y) and L(x, y). According to this calculation, G(y) is a maximum in the character string. A noise component generated at the time of a binarization is not correlated, so that a contribution to G(y) can be substantially neglected.