GB1126574A - Improvements in or relating to apparatus for use in the automatic recognition of characters - Google Patents

Abstract

1,126,574. Character recognition. SIEMENS A.G. 29 Sept., 1965 [29 Sept., 1964], No. 41325/65. Heading G4R. Character recognition apparatus comprises means to determine elementary areas delimiting a boundary of a window containing the characters, and means to infer from this determination the positions of other elementary areas delimiting the boundary. Referring to Fig. 2, signal elements obtained by columnwise scanning of the window and its borders are " one " if originating from a character or the window border and " zero " if from a non-character point within the window, and are passed from line (n + 1) via two onecolumn-delay registers vR, R in series to a gate Gk<SP>*</SP>. A unit FY fed by the outputs of these registers enables one input of a gate GYF<SP>*</SP> during the window portion of each column which crosses the window but not any character. The gate GYP<SP>*</SP> is blocked at a second input during the first and last elements of the window portion via an OR-gate OG fed from taps on delay registers R, nR through which the signal elements pass. The gate GYP<SP>*</SP> thus provides a truncated window signal which is stored in a recirculating register YF<SP>*</SP> (until the next column crossing the window but not a character) and used to enable one input to gate Gk*. A blocking input of gate Gk<SP>*</SP> is energized following detection of a column entirely in the trailing window border (by a unit YFE) and due to the two-column delay in registers vR, R this replaces the immediately preceding column by all " zeroes " at the output of gate Gk<SP>*</SP>, which leads to recognition circuitry. Fig. 3 shows an alternative arrangement for producing the truncated window signal using a recirculating delay register YF storing the untruncated window signal and feeding a gate Gyf<SP>*</SP> from one tap thereon. The gate Gyf<SP>*</SP> is blocked at another input to perform the truncation by blocking gates controlled from taps one element earlier and later. Fig. 3 also shows schematically a preceding arrangement comprising a delay register RR to hold signal elements for a complete character and means b to count the columns crossing the window, insert the count minus one into a (further) counter when the first column crossing the window but not a character is reached, and then increment the counter by one for each subsequent column until its capacity is reached when a gate in the output of the register RR is enabled. Thus the signal elements in the first column to cross the window are not passed. The truncation of the window signals and the deletion of the first and last columns in the window, avoid parts of the window border being taken as parts of characters even if the characters run into the borders and the boundaries between window and borders (as detected) are skew or uneven.