| 摘要 |
1477876 Character recognition systems TOKYO SHIBAURA ELECTRIC CO Ltd and T IIJIMA 8 Aug 1974 [8 Aug 1973] 34946/74 Heading G4R The pattern to be recognized is compared with reference patterns in each of K categories to identify the unknown with one of the categories. Each category comprises M first and N second reference patterns. The inner product between the unknown and the reference patterns is determined optically or electrically for each category. The results are applied to squaring, adding, and comparing circuitry to identify the pattern. The M reference patterns in any one category represent certain variations of the pattern represented by that category (e.g. O) and the N patterns represent patterns in other categories (e.g. D, Q) that are closely similar to the category. The operations performed by the system ensure a tolerant discrimination with respect to those pattern components within a category which are not readily confused with those of another category, but ensure a severe discrimination with respect to those components which are readily confused. In any one category the M first patterns are orthonormal one to another, and the N second patterns are orthogonal to the first patterns and orthonormal to one another but are included in categories easily confused with this category. Reference is made to the identification of sounds. In one embodiment the unknown pattern f is applied to each of K category circuits. Fig. 5 shows a circuit. Circuits 511-51M and 541- 54N respectively calculate the inner products between f and reference patterns #1-#M and #1-#N. The resulting inner products a1-aM, b1-bM are squared to provide c1-cM and d1-dN. The squares are summed, giving ik, jk. The square of the norm off is calculated and a multiple of the result added to jk to give pk. If ik is greater than pk it is deemed that the unknown pattern f is represented by the pattern An alternative embodiment (Fig. 12, not shown) employs K circuits, each comprising means for calculating the sums i1-iK of the squares of the inner products of f and the MK first reference patterns, and the sums j1-jK of the squares of the inner products off and the NK second reference patterns. The values tr of ir-jr are determined and the maximum tr found in order to identify the pattern. In a third arrangement, Fig. 13, the inner products are determined by applying the optical unknown pattern f to reference pattern filters #1-#M and #1-#N (only three shown) for one category. The filters are viewed by photocells which provide inner product signals to the squaring circuits of Fig. 5. Each filter may carry K reference patterns and present them in turn to the unknown pattern f. |
