Diagram recognizing system

Abstract: A diagram recognizing (300) system is capable of automatically recognizing a diagram prepared, for example, through a manual operation or through a drawing software, in such a manner as independent from a CASE tool or the like, and delivering a recognized logic to the CASE tool or the like without the aid of any manual operation. A recognizing rule for recognizing the diagram as the object of recognition is entered and stored (25a), and a symbol, a connecting line, a character string, and a relationship of connection between the symbols, each structuring the diagram, are recognized on the basis of the recognizing rule by a diagram recognizing means (25b) and logical data, indicative of the kind of each of the symbols, the character string, and the relationship of connection between the symbols, is generated, and the logical data is converted (500) into and generated as a predetermined file type so as to be delivered directly to the CASE tool or the like.

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diagram recognizing system and, more particularly, to a diagram recognizing system so adapted as to recognize a diagram to be employed for describing a specification for data processing, such as flowcharts, data flow diagrams, and the like, of documents for developing and maintaining a data processing system, to convert the recognized diagram into logical data indicative of its logical meaning and to generate the logical data. 2. Description of the Related Art Recently, there have been proposed and employed techniques for analyzing and designing a system, having both of accuracy in the specification for data processing and ease in understanding it, by representing a procedure of the data processing for a data processing system or the like. For instance, such techniques may include a structured analysis technique proposed by T. DeMarco (DeMarco, T.; Structured Analysis And System Specification; Prentice-Hall, 1978) and a technique for information engineering, systematized by J. Martin (Martin, J.; Information Engineering, Book I: Introduction, Prentice-Hall, 1989). As a specific example of these techniques, there is commercially employed a reverse engineering system for forming an entity relationship diagram from definition data of DB2, IDMS, VSAM, and IMS, which are IBM's database and files, as a tool for forming a logical structure of data from the database definition data of text file data such as a source program of a developed information system, database definition data, job control statement, linkage parameter, input-output map, and the like, as indicated by Data Analyst of Buchman, Inc. (Sato, M.; CASE Tool; Explanation of Its Functions and Know How of Its Application, page 219, Nov. 1, 1989). On the other hand, as CASE (Computer Aided Software Engineering) tools for aiding operations for forming a source program on the basis of these techniques, there have been commercialized Excelerator (Index Technology, Inc.) and IEW (Information Engineering Workbench: KnowledgeWare, Inc.), which are employed mainly in the U.S. and Europe (Nakamura, M.: Evolving CASE; Exploding "Walls" Among steps & Providing Smooth Development Environments: Nikkei Computer; pages 78-101, Nov. 5, 1990). It can be noted, however, that the CASE tools which set the formation of a diagram forth as a premise are thought to spread even in the U.S. at a rate as high as 10%, so that the situation is not yet ripen in which system analysts and system engineers can always utilize the CASE tools. Hence, system analysts and system engineers are usually employing techniques for manually drawing diagrams with rulers, templates and the like and allowing operators to enter the diagrams into the CASE tools or for forming diagrams by making use of a drawing software, which is far less expensive than the CASE tools, and entering the formed diagrams into the CASE tools. The diagrams formed manually or through the drawing software in the manner as described hereinabove, however, are independent from the CASE tools, so that the delivery to downstream steps, such as the verification of matching with the specification as the CASE tool, the editing to be done with the logical meaning of the diagrams taken into account, and the automated formation of engineering data or a source program, should be conducted by manual operations. Hence, these techniques present the problems that the verification of accuracy of conversion operations, compliance of the specification with the program, maintenance of the diagrams, and the like are rendered very difficult. At this end, demands have been made to develop and realize a system that can automatically recognize a diagram formed manually or through a drawing software and deliver the diagram to the CASE tool without any manual assistance. It can be noted herein that, as a similar technique, for instance, Hitachi, Ltd. has commercialized an intelligent system for recognizing account books and vouchers (BELIEVE) (Tsuchiya, M.; Jimu to Keiei: An Intelligent System for Recognizing Account Books & Vouchers As An Instant Power Potential; pages 8-10, September, 1990). This system is so adapted as enter accounting vouchers and slips as data of an image, to allow a recognition of a voucher style and a recognition of fields, and to automatically form programs for implementing operations for issuing the vouchers and printing the books. Further, Japanese Patent Publication Laid-open (kokai) No. 71,366/1990 discloses a system for forming an E-R model, which is so adapted as to enter an entity relationship diagram (an E-R model diagram) for forming a model of data within an information system, as data of an image, and to allow a graphic recognition to thereby form the E-R model in an automatic way. In addition, as indicated by M. Hirata (An Input System for Automatically Entering Drawings of Logical Circuits: Demonstrating Its Effect by Restricted Uses; Nikkei Computer Graphics; page 18, February, 1988), a system for automatically recognizing a drawing of a logical circuit, developed by Matsushita Electric Industries, Co., Ltd., is so adapted as to read the drawing of the logical circuit of hardware as data of an image, to recognize symbols, characters, and relationship of connection between the symbols, and to store them in database. The system for automatically recognizing the drawing of the logical circuit, however, is so adapted as to enter the drawing of the logical circuit of the hardware, so that it cannot be applied to the recognition of a diagram describing a data system. The diagram describing the data system offers the characteristics that it is important to distinguish the directivity of the relationship of connection between the symbols, that the number of connecting lines to be connectible to each of the symbols is optional, that there is regularity among the connectible symbols, that the shape and the meaning of each of the symbols can be modified or added for each user, and the like. Hence, the problem resides in the fact that the automated system cannot be applied to the recognition of the diagram such as data flow diagrams, entity relationship diagrams, flowcharts, and the like. Further, the intelligent system for recognizing the account books and vouchers, as described hereinabove is so designed as to recognize formats, such as account books and vouchers composed of spreadsheets which are delimited and surrounded by straight lines only, to detect positions of the characters within the format, and to recognize the data. This system, however, presents the problem that it cannot recognize data in such a form as a diagram in which the positions of symbols, connecting lines or a sequence of characters cannot be defined in advance. Furthermore, the system for forming the E-R model as described hereinabove is designed exclusively for forming the entity relationship diagram in which the number of symbols to be employed is limited to several kinds; hence, it has the problem that, although it can be applied only to the recognition of the shape and the meaning of a predetermined diagram, it cannot be applied to the recognition of a diagram that should be defined by each user in a manner as have conventionally been conducted. From IEEE Proceedings 6th International Conference Software Engineering, IEEE cat no. 82CH1795-4 an automatic input of flow chart in document image is known. The technology of document image processing has the possibility of automatic document input. By utilizing it, the flow chart in document image as the alternate expression of FORTRAN source statements is automatically input into the computer. The paper reports the algorithm and the experimental results of field segmentation and classification in document image, the recognition of flow chart including control lines and blocks, and hand-written alphanumerical characters in the blocks and the explanatory fields, the conversion of flow chart into program functions and the generation of FORTRAN source statements. Further, in Pattern Recognition, vol. 19, no. 2, 1986, p. 147-160 an online hand-sketched figure recognition is described by H. Murase. An online algorithm capable of recognizing hand-sketched symbols such as those used in flowcharts has three steps: (1) candidate figure extraction for each symbol based on a graph search and distance calculation between candidate figures and reference patterns, (2) selection of the symbol sequence which minimizes the total sum of these distances, (3) connection rules application. From IEEE Transactions on Pattern Analysis and Machine Intelligence, vol. 12, no. 10, October 1990, p. 978 a system for interpretation of line drawings is known. An algorithm is described to locate and separate text strings of various font size, style, and orientation. This is accomplished by applying the Hough transform to the centroids of connected components in the image. The graphics in the segmented image is processed to represent thin entities by their core-lines and thick objects by their boundaries. The core-lines and boundaries are segmented into straight line segments and curved lines. The line segments and their interconnections are analyzed to locate minimum redundancy loops which are adequate to generate a succinct description of the graphics. Such a description includes the location and attributes of simple polygonal shapes, circles, and interconnecting lines, and a description of the spatial relationships and occlusions among them. Hatching and filling patterns are also identified. From IEEE Proceedings Workshop Computer Architecture for Pattern Analysis and Image Database Management, IEEE cat no. 85CH2229-3, 1985, p. 524 a knowledge-controlled pattern recognition technique for hand-drawn logic symbols is known. A high-performance logic circuit diagram reader for CAD data input is described. For the purpose of easy system improvement and recognition accuracy, the reader has employed a knowledge controlled pattern recognition technique, where object-oriented information are explanatorily separated from the analysis process and formalized as knowledge (low level knowledge). From EP-A-0 279 158 a method and apparatus for recognition of graphic symbols is known. A technique for recognizing hand-drawn graphic symbols operates on vectorized graphic data, including lines, arcs, and circles, that have been produced by an automatic drawing recognition system. The user creates segmented rule bases for recognizing various symbols by describing the geometric structures of recognizable symbols and subsymbols. The rule bases each are compiled into a respective decision tree. Fetched input vectors and entities are placed in software "blackboards", and more particularly, into appropriate symbol slots and subsymbol slots thereof. The growing symbol and subsymbols on the blackboards are continually restructured until they form closed loops or the blackboards are filled. The decision tree then is applied to all possible permutations of the symbols and/or subsymbols to accomplish partial or complete recognition. An inference engine subsystem controls application of the decision trees to limited bits of the symbols and subsymbols, matching decision subtree segment labels to attributes associated with the blackboard data, and orders the matched data according to degree of matching to effectuate application of the decision tree to the linked lists. Further, from IEEE Proceedings 10th International Conference Pattern Recognition, vol. 1, 1990, p. 578 a recognition method for roughly hand-drawn logical diagrams based on hybrid utilization of multi-layered knowledge is known. The method is free from various drawing constraints which previous systems cannot avoid. It is based on two concepts. As the first concept, no strict segmentation should be performed. Various hypotheses of symbols should be considered. As the second concept, various kinds of knowledge should be utilized. Ambiguity of figure can be dissolved from wide knowledge. SUMMARY OF THE INVENTION Therefore, the object of the present invention is to solve the problems presented by the prior art techniques and to provide a diagram recognizing system capable of automatically recognizing a diagram prepared in such a manner as formed manually or through a drawing software, or as formed independently from the CASE tool, particularly a diagram which has a directivity with respect to the relationship of connection between the symbols, in which the positions of the symbols are not defined in advance, and which is defined optionally by each of the users, and capable of delivering the recognized logic to the CASE tool or the like without any manual operation. This object is achieved by a diagram recognizing system with the features of claim 1 and a diagram recognizing method as set forth in claim 7. Particular embodiments of the invention are subject of the depending claims. In order to achieve the aforesaid object, the present invention consists of a diagram recognizing system comprises a diagram input means for entering a diagram to be employed for describing a specification of data processing as data of an image, which is composed of a symbol to be represented by a drawing such a circle, a rectangle and the like, a connecting line having a directivity indicative of a connection between symbols, and a character string to be provided on the symbols and the connecting line, such as a flowchart, a data flow diagram or the like; a recognizing rule input means for entering a recognizing rule for recognizing the diagram to be entered by the diagram input means; a recognizing rule storing means for storing the recognizing rule entered by the recognizing rule input means; a diagram recognizing means for recognizing the symbol, the connecting line, and the character string, each structuring the diagram entered from the diagram input means, as well as the connected relationship of the connection of the symbols, on the basis of the recognizing rule stored by the recognizing rule storing means, and for generating the kind of the symbol and the character string as well as the connected relationship of the connection between the symbols as logical data; and a conversion means for converting the logical data generated from the diagram recognizing means into a predetermined file format. With the arrangement as described hereinabove, the recognizing rule for recognizing the diagram as the object of recognition is entered from the recognizing rule input means, and it is stored in the recognizing rule storing means. Then, the diagram as the object of recognition is entered as the data of the image from the diagram input means. Upon the input of the diagram as the data of the image, the diagram recognizing means recognizes the symbols, the connecting lines, and the character string, each structuring the diagram entered from the diagram input means, as well as the relationship of connection between the symbols on the basis of the recognizing rule, and it generates the kind of the symbols and the character string as well as the relationship of connection between the symbols as the logical data. The logical data generated from the diagram recognizing means is converted into a predetermined file format by the conversion means so as to be delivered directly to the CASE tools or the like and then generated. Other objects, features and advantages of the present invention will become apparent in the course of the description of the preferred embodiments, which follows, with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram showing a data processing system according to a first embodiment of the present invention. Fig. 2 is a flowchart showing a whole procedure for processing the data processing system according to the first embodiment of the present invention. Fig. 3 is a view showing an example of a diagram to be entered in the first embodiment according to the present invention. Fig. 4 is a schematic representation showing an example of logical data to be generated as the result of recognition according to the first embodiment of the present invention. Fig. 5(a) is a schematic representation showing a portion of data of an image for a symbol entered as a diagram. Fig. 5(b) is a table for describing the store structure. Fig. 6(a) is a schematic representation showing an example of data of a vector converted from the symbol in Fig. 5(a). Fig. 6(b) is a table of a graphic for describing the data of the vector as shown in Fig. 6(a). Fig. 6(c) is a table of line segments for describing the data of the vector as shown in Fig. 6(a). Fig. 7 is a table for describing the definition of the recognizing rule for recognizing symbols. Fig. 8 is a table for describing the definition of the recognizing rule for recognizing connecting lines. Fig. 9 is a table for describing the definition of the recognizing rule for recognizing the connected relationship of connection among the symbols. Fig. 10 is a flowchart showing the details of the diagram recognizing processing. Fig. 11 is a flowchart showing the symbol recognizing processing and the flow recognizing processing, each using no recursive processing. Fig. 12 is a table showing a portion of data indicating the intermediate result of recognition. Fig. 13 is a table showing a portion of data indicating the intermediate result of recognition. Fig. 14 is a flowchart showing the symbol recognizing processing and the flow recognizing processing of Fig. 10, with the recursive processing employed therein. Fig. 15 is a block diagram showing a data processing system according to a second embodiment of the present invention. Fig. 16 is a flowchart showing a whole procedure of processing the data processing system of Fig. 15. Fig. 17 is a table for describing another example of the definition of the recognizing rule for recognizing symbols. Fig. 18 is a table for describing another example of the definition of the recognizing rule for recognizing connecting lines. Fig. 19 is a table for describing another example of the definition of the recognizing rule for recognizing the connected relationship of connection among the symbols. Fig. 20 is a table for describing the calculation of evaluation points for the recognizing method. Fig. 21 is a schematic representation indicating the result of recognition on the basis of the result of calculation of the evaluation points for a shape of the graphic. DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described more in detail with reference to the accompanying drawings. Fig. 1 is the block diagram showing the data processing system according to the first embodiment of the present invention. The data processing system according to the first embodiment of the present invention comprises an image input unit 1 for entering a diagram as the object of recognition as data of an image, a data processing unit 2 for implementing the processing for recognizing the diagram, an input display unit 3 for allowing the user to correct the result of recognition, and an output file 4 for storing the result of recognition. The data processing unit 2 comprises an image data input section 21 for entering data of an image of the diagram that is represented by logic 1 and logic 0 corresponding to the presence and the absence of the image of a pixel on a plane of the diagram on which the diagram is read, respectively; an image data storing section 22 for storing the data of the image entered by the image data input section 21; a data converting section 23 for converting the data of the image stored in the image data storing section 22 into data of a vector as an aggregate of line segments; a vector data storing section 24 for storing data of the vector; a recognizing rule storing section 25a for describing a logical recognizing rule, such as the kind of the diagram corresponding to a graphic characteristic, the relationship of connection between the diagrams, and the like, in order to recognize the diagram; a diagram recognizing section 25b for recognizing the diagram by matching the recognizing rule stored in the recognizing rule storing section 25a with the data of the vector stored in the vector data storing section 24; an intermediately recognized data storing section 26 for storing the result of recognition obtained by the diagram recognizing section 25b; a correction section 27 for correcting an unrecognizable portion of the result of recognition stored in the intermediately recognized data storing section 26 through a manual operation by the user on the image display unit 3; a recognized data storing section 28 for storing the corrected result of recognition corrected by the correction section 27; and a recognized result converting section 29 for converting the contents of the recognized data storing section 28 into a data format in the output file 4. For the data processing unit 2 having the structure as described hereinabove, the recognizing rule is stored in the recognizing rule storing section 25a and entered prior to the recognition processing from the image display unit 3 through the manual operation by the user. Further, the recognizing rule can be modified or added thereafter through the image display unit 3. Fig. 2 is the flowchart showing an outline of the processing procedure through the data processing unit 2. First, at step 100, a diagram as the object of recognition is read by the image input unit 1 and data of an image of the diagram is stored by the image data storing section 22 through the image data input section 21. Then, at step 200, the data of the image stored in the image data storing section 22 is read by the data converting section 23; it is then subjected to the processing for removing noises, thinning lines, and the like, by the data converting section 23; it is further converted into the data of the vector which is a collection of data indicative of an aggregate of line segments and representing a closed graphic or an open graphic; and it is stored in the vector data storing section 24. It is noted herein that a description on a detail of the technique for converting the data of the image into the data of the vector will be omitted because the technique is known as is described, for example, in a paper entitled "Making Input of Data for CAD Efficient: Highlighting An Automated Input Device for Drawings" by M. Hirata (Nikkei Computer, page 82, issued March 3, 1986). Then, at step 300, the diagram recognizing section 25b is so adapted as to read the data of the vector stored in the vector data storing section 24 and the recognizing rule for recognizing the diagram, stored in the recognizing rule storing section 25a; to implement the processing for matching the data of the vector with the recognizing rule so as to recognize the diagram represented in the data of the vector; and to store the result of recognition in the intermediately recognized data storing section 26 as an intermediate result of recognition. Further, at step 400, an inquiry is made through the image display unit 3 about an unrecognizable portion of the intermediate result of recognition stored in the intermediately recognized data storing section 26, thereby requiring the user to enter necessary data, and the unrecognized portion is corrected by the correction section 27 to provide a complete result of recognition of the diagram entered. The corrected result of recognition is then stored in the recognized result storing section 28. At step 500, the recognized data converting section 29 is so adapted as to convert the data of the result of recognition stored in the recognized result storing section 28 into the logical data in a data format predetermined by the output file 4, for example, in such a data format as capable of being delivered directly to the CASE tool, and it stores the resulting logical data in the output file 4. Hence, the CASE tool as described hereinabove can carry the data over immediately to a downstream step without any manual operation on the basis of the logical data stored in the output file 4. Then, a description will be made of an specific example of the recognition processing for recognizing the diagram with reference to Fig. 3 showing an example of a data flow diagram entered as the data of the image through the image input unit 1. This diagram may be written manually or drawn through a drawing software and the logical relationship between the symbol and the connecting line for connecting the symbols can be judged only by the user. The diagram recognizing system according to the present invention is so adapted as to recognize such a diagram and to form logical data representing the name and the kind of the symbols and the relationship of connection between the symbols, as shown in Fig. 4. Fig. 5(a) indicates an example of an image corresponding to a portion of the data flow diagram, as shown in Fig. 3, stored in the image data storing section 22. In Fig. 5(a), reference numeral 701 represents an example corresponding to a portion of the data of the image around a diagram indicative of a character string "ORDER PROCESSING" of Fig. 3, surrounded by a circular symbol 704. Fig. 5(b) indicates a state of the pixels storing the data of the image corresponding to the portion as represented by reference numeral 702 in Fig. 5(a). The pixels indicated by "0" mean ones in which no image exist, and the pixels indicated by "1" mean ones in which the image exists. Figs. 6(a), 6(b) and 6(c) show an example of the data of the vectors converted from the data of the image, as shown in Fig. 5, which is stored in the vector data storing section 24. In Fig. 6(a), reference numeral 801 indicates an example of the data of the vector converted from the image data 701, which is displayed on the image display unit 3. The circular symbol 704 surrounding the sequence of the characters "ORDER PROCESSING" may be broken down into twelve line segments L1, L2, ...., L12, and each of the line segments is represented by data in a vector type. Likewise, an arrow 705 may be divided into four line segments L13, L14, L15, and L16, and each of the line segments is represented by data in a vector type. The vector data 801 as represented hereinabove is stored as a closed graphic or an open graphic as the unit of storage in a graphic table 802 of the vector data storing section 24. As specifically shown in Fig. 6(b), the graphic table 802 comprises data 803 of identification number of graphics (Graphic ID Nos.), indicative of an aggregate of line segments, data 804 of a class indicative of the closed graphic or the open graphic, data 805 indicative of an arrangement for the line segments structuring the graphic classified in the class data 804, and data 806 of a branched point or points of the corresponding graphic, indicative of the coordinates of the branched point or points. Further, as shown in Fig. 6(c), each of the line segments is so structured as to be managed by a line segment table 807 which in turn stores each of the line segments and comprises data 808 of the identification number of the line segment, data 809 of coordinates of a starting point of the line segment, and data 810 of coordinates of an ending point thereof. It is to be noted herein, however, that the coordinates (x1, y1) of a branched point branched from the line segment L11 to the line segment L15 in Fig. 6(a) are represented on the drawing for reference only, and they are not displayed actually on a display screen. Figs. 7, 8 and 9 are each an example of the recognizing rule for recognizing the data flow diagram stored in the recognizing rule storing section 25a. The recognizing rule for recognizing the diagram comprises a symbols recognizing rule 1000a for recognizing symbols, a flows recognizing rule 1010a for recognizing connecting lines (flows), and a relationship recognizing rule 1020a for recognizing the relationship of connection between the symbols, respectively. As shown in Fig. 7, the symbols recognizing rule 1000a contains data 1001a of the kind of symbols representing external agent such as users, process, and files, and the like; data 1002a of classification of the symbol into a simple graphic such as a circle, a rectangle, etc., or a composite graphic such as a combination of the simple graphics; data 1003a of shapes of the symbols, indicative of a graphic characteristic of the corresponding symbol; data 1004a of positions indicative of the location of the character string inside or outside the corresponding symbol; and data 1005a of the directivity of the characters, horizontal or vertical, in which the characters are written on the symbol. For example, when the data 1003a of the shape of the symbol represents the symbol as a rectangle, the symbol is defined by data consisting of four line segments of a long vector, no line segment of a short vector, four right angles, and two pairs of parallel lines. Further, the shape of the symbol recognized by the symbol recognizing rule 1000a is illustrated by reference numeral 1006a as shown in Fig. 7(a). As the recognizing rule representing the data 1003a indicative of the shapes of the symbols, as shown in Fig. 7, there may be employed the number of long vectors, a minimum of the number of short vectors, a minimum and a maximum of the number of acute angles, a minimum and a maximum of the number of right angles, a minimum and a maximum of the number of obtuse angles, a sum of angles between the long vectors, a minimum and a maximum of the number of pairs of parallel lines, and the like. A class of the symbol indicative of the closed graphic or the open graphic may be added thereto. Further, as the recognizing rule, there may be added a minimum of the length to be recognized as the long vector and a maximum of the length to be recognized as the short vector. In addition, rules may be added in accordance with the symbols to be recognized or the graphic characteristics of the flows, in order to improve a rate of recognition. As shown in Fig. 8, the flows recognizing rule 1010a contains data 1011a of the kind of the flows, indicative of a single direction of the connecting line or a both-sided direction thereof; data 1012a of the position of the arrow, when the connecting line is provided with the arrow; data 1013a of the shape of the flow, indicative of the graphic characteristic of the connecting line; data 1014a of the position of the character string corresponding to the connecting line; and data 1015a of the direction, horizontal or vertical, in which the character string are written on the connecting line. In the data 1013a of the shapes of the flows, for instance, the connecting line in the single direction may be defined by data consisting of the number of the line segments of a long vector being one or more, the number of the acute angles being one, and the number of the line segments of a short vector being two. The shape of the connecting line to be recognized by the flows recognizing rule 1010a is illustrated by reference numeral 1016a, as shown in Fig. 8. As shown in Fig. 9, the relationship recognizing rule 1020a for recognizing the relationship of connection between the symbols consists of a combination of data 1021a of the kind of the input symbol with data 1022a of the kind of the output symbol; the data 1021a indicative of the kind of the input symbol may contain the external agent such as a user and the like, the process, and the file, and the data 1022a indicative of the kind of the output symbols may likewise contain the external agent, process, and the file. Further, the relationship recognizing rule 1020a is so arranged as to represent data 1023a and data 1024a in a matrix type, the data 1023a being indicative of a unconnectable combination of the data 1021a of the kind of the input symbol with the data 1022a of the kind of the output symbol and the data 1024a being indicative of the kind of connectable lines in the combination of the data 1021a with the data 1022a. As shown in Fig. 9, for instance, it is defined that the external agent, such as a "user", as the input symbol cannot be combined with the external agent, such as "user", as the output symbol and the file, such as "shipment file", as the input symbol cannot be combined with the file such as a "shipment file" as the output symbol. Hence, in this case, for instance, a cell that exists under the column "EXTERNAL AGENT" in the row 1022a "KIND OF OUTPUT SYMBOLS" and that exists in the row "EXTERNAL AGENT" under the column 1021a "KIND OF INPUT SYMBOLS" is indicated as "UNCONNECTABLE", as indicated by reference numeral 1023a, because the data on the external agent under the column located in the row 1022a is not connectable with the data on the external agent in the row located under the column 1021a. Likewise, when the data existing under the column in the row 1022a is unconnectable with the data existing in the row under the column 1021a, the corresponding cells are filled with the word "UNCONNECTABLE". For instance, the cell corresponding to the file as the kind of the output symbol and to the external agent as the kind of the input symbol is filled with the word "UNCONNECTABLE". On the other hand, the data 1021a of the kind of the input symbols relating to the external agent is to be connected with the data 1022a of the kind of the output symbols relating to the process, as shown in Fig. 9. Hence, in this case, the cell corresponding to both of the data in the row "EXTERNAL AGENT" and under the column "PROCESS" is filled with words "SINGLE-DIRECTED FLOW OR DOUBLE-DIRECTED FLOW", as indicated by reference numeral 1024a. Likewise, all the cells defined in this manner are filled with the same words. Fig. 10 is the flowchart showing a detail of the diagram recognizing processing at step 300 in Fig. 2, and Fig. 11 is the flowchart showing a detail of the processing for recognizing the symbols and the flows at step 350 in Fig. 10, without using any recursive processing. Now, a description will be made of the operations for recognizing the diagram represented in a vector type, with reference to the flowcharts as shown in Figs. 10 and 11. First, at step 310, the diagram recognizing section 25b reads data of a vector relating to the diagram as the object of recognition, which is stored in the vector data storing section 24, followed by proceeding to step 320 at which the recognizing rule stored in the recognizing rule storing section 25a is read. Then, at step 330, the diagram recognizing section 25b is so adapted as to separate the data of the vector indicative of a line segment having a length shorter than a predetermined length as a candidate of a character string. Further, at step 340, a search is made for the graphics indicated in the class data 804 of the graphic table 802 stored in the vector data storing section 24, and one closed graphic is fetched and set as a first object of recognition. More specifically, for example, in the data of the vector as shown in Fig. 6(a), the class data 804 indicative of the symbol 704 surrounding the character string "ORDER PROCESSING" indicates the closed graphic, as shown in Fig. 6(b), so that the symbol 704 is set as the first object of recognition. Then, at step 350, the recognition processing for recognizing the symbols and the flows, as shown in Fig. 11, is called using the symbol as an argument, thereby recognizing the kind of the symbol set as the first object of recognition on the basis of the symbol recognizing rule 1000a. For example, for the symbol 704 for the character string "ORDER PROCESSING" as shown in Fig. 6(a), the graphic table 802 is so arranged as to store the line segments L1 to L12, inclusive, structuring the symbol 704 and the line segment table 807 is so arranged as to store a detail of the positions indicated by the data 809, indicative of the coordinates of the starting point of each line segment, and the data 810, indicative of the coordinates of the ending point thereof. On the other hand, as shown in Fig. 7, the symbols recognizing rule 1000a for recognizing the symbols is so arranged as to define the shape of the symbol under the column "SHAPE OF SYMBOL", as indicated by reference numeral 1003a, corresponding to the row "PROCESS", as indicated by reference numeral 1001a, by no long vectors, a large number of short vectors, a large number of obtuse angles, and the like. In the recognition processing at step 350, the length of each of the line segments L1 to L12, inclusive, is given by the data 809 indicative of the coordinates of the starting points and the data 810 indicative of the coordinates of the ending points, thereby determining the numbers of the long vectors and the short vectors. In addition, the direction of each of the line segments is determined by the data 809 and the data 810, and an angle of the adjacent line segments is given for each of pairs of the adjacent line segments, thereby determining the numbers of acute angles, obtuse angles, right angles, and pairs of the parallel lines. Then, data of the numbers of the long vectors, the short vectors, the acute angles, the obtuse angles, the right angles, and the pairs of the parallel lines is compared with the data 1003a of the shapes of the symbols in the symbol recognizing rule 1000a. When it is found as a result of comparison that the symbol 704 for the character string "ORDER PROCESSING" agrees with the shape of the symbol under the column 1003a corresponding to the row "PROCESS" under column 1001a indicative of the kind of the symbol, then the symbol 704 is recognized as the kind of the symbol under the column 1001a "PROCESS". Thereafter, it is decided to determine if the line connected to the symbol involved exists, by determining if the data 806 of a branched point exists in the graphic table 802 as data of a vector corresponding to the symbol. When the result of decision indicates that the connected line exists, on the one hand, then the data of the vector of a partner symbol, which exists on the side opposite to the symbol and beyond the connected line, is recognized together with the data of the vector of the connected line, the kind of the connected line is recognized in accordance with the flows recognizing rule 1011a, and the adaptability to the logic is inspected as to the determination if the partner symbol is allowed to be connected in accordance with the relationship recognizing rule 1020 for recognizing the relationship of connection between the symbols. Thereafter, at step 360, a character string corresponding to the symbol 704 is detected, and the relationship of correspondence is stored in a column "ID OF CORRES. CHARACTER STRING", as indicated by reference numeral 904, in a symbols table 900 prepared in the intermediately recognized data storing section 26, as shown in Figs. 12 and 13. The intermediately recognized data storing section 26 comprises the symbols table 900, a flows table 910, a character string table 920, a vector data storing section 930, and a stack 940. As shown in Fig. 12, the symbols table 910 may contain data of the identification of symbols under column 901 indicated by "SYMBOL ID", which is represented, for example, by 'S1', 'S2', and the like; data of the kind of the symbols under column 902 indicated by "KIND OF SYMBOLS", which is represented, for example, by 'EXTERNAL AGENT', 'PROCESS' and the like; data of the appropriateness or inappropriateness of the result of recognition of the symbol under column 903 indicated by "DECISION OF RECOGNITION", which is represented, for example, by 'OK' or 'NG'; data of the identification of corresponding character string under column 904 indicated by "ID OF CORRES. CHARACTER STRING"; and data of the vector corresponding to the connected line determined as the object of recognition, under column 905 indicated by "CORRES. VECTOR DATA". Fig. 12 further shows the flows table 910 which may contain data of the identification of flows under column 911 indicated by "FLOW ID", which is represented, for example, by 'f1', 'f2', and the like; data of the direction of the flow under column 912 indicated by "DIRECTION OF FLOW", which is represented by 'SINGLE' for a single direction, 'BOTH' for both directions, or 'NONE' for no direction; data of the identification of input symbols showing the input symbols under column 913 indicated by "INPUT SYMBOL ID"; data of the identification of output symbols showing the output symbol under column 914 indicated by "OUTPUT SYMBOL ID"; data of the results of recognition of the flows under column 915 indicated by "DECISION OF RECOGNITION"; data of the relationship of connection between the symbols connected through the connected line, under column 916 indicated by "DECISION OF CONNECTION"; data of the identification of the corresponding character string provided on the connected line, under column 917 indicated by "ID OF CORRES. CHARACTER STRING"; and data of the vector corresponding to the connected line determined as the object of recognition, under column 918 indicated by "CORRES. VECTOR DATA". As shown in Fig. 13, the character string table 920 may contain a column 921 indicative of data of the identification of character strings; a column 922 indicative of data of the results of recognition of the character strings; a column 923 indicative of data of codes of the characters of the recognized character string; and a column 924 indicative of the data of the vector corresponding to the character string determined as the object of recognition. Fig. 13 further shows the vector data storing section 930 which is so adapted as to correspond the data of the vector prior to recognition to the symbols, flows and character strings subsequent to recognition. Data of each of the symbols, flows and character strings subsequent to recognition is stored in substantially the same type as in the graphics table 802 and the line segments table 807 as shown in Fig. 6. In addition, as shown in Fig. 13, the stack 940 is so adapted as to store data 941 indicative of the identification of partner symbols for the symbols as the object of recognition. The example as shown in Fig. 13 indicates that partner symbols "ORDER PROCESSING" and "SHIPMENT PROCESSING", whose identification is S2 and S3, respectively, are temporarily stored during the course of the processing for the symbol "USER" as the object of recognition, whose identification is S1. Turning back to Fig. 10, the relationship of correspondence of the character string corresponding to the symbol as the object of recognition is stored at step 360 under the column 904 indicative of the identification of the corresponding character string of the symbols table 900 and then, at step 370, the character string corresponding to the connected line is detected on the basis of the vector data 809 and 810 indicative of the coordinates of the starting point and the ending point, respectively, of the connected line recognized and the data 1014a indicative of the position of the character string in the recognizing rule, and this relationship of correspondence is stored in the flows table 910 of Fig. 12 as data 917 indicative of the identification of the corresponding character string. Thereafter, at step 380, the corresponding character string is recognized by a characters recognizing technique which has been conventionally utilized for an optical character reader (OCR) or so on, the suitability or unsuitability of the result of recognition is stored in the character string table 920 of Fig. 13 as data 922 for judging the result of recognition, and, when it is found that the result of recognition is suitable, the code of the character is stored in the character string table 920 as character code data 923. It is to be noted herein that steps 360 and 370 are exchangeable. In Figs. 12 and 13, reference numerals (1) to (5), inclusive, are intended to mean the relationship of correspondence between the data connected through the broken lines indicated by the respective reference numerals (1) to (5). A description will now be made of a detail of the processing at step 350 of Fig. 10 with reference to the flowchart as shown in Fig. 11. At step 351a, the data of the vector of the symbol as the object of recognition, to be delivered as an argument, is matched with the data 1003a indicative of the shape of the symbol, defined in the symbols recognizing rule 1000a, and the symbol identification data 901, the data 902 indicative of the kind of the symbol, the data 903 indicative of the decision of the result of recognition, and the data 905 indicative of the corresponding data of the vector are stored in the symbols table 900 of the intermediately recognized data storing section 26. Then, at step 352a, it is decided to determine if the connecting line connected to the symbol as the object of recognition exists, by determining if the data 806 indicative of the branched points exists in the data of the vector relating to the symbol as the object of recognition contained in the graphics table 802. When it is decided at step 352a that the connected line exists, on the one hand, then the program flow goes to step 353a at which a partner symbol is acquired which is located on the side opposite to the symbol as the object of recognition and beyond the connected line. Then, at step 354a, the data 1003a of the shapes of the symbols in the symbols recognizing rule 1000a is matched with the data of the vector of the partner symbol, followed by proceeding to step 355a at which data 1012a indicative of the position of the arrow in the flows recognizing rule 1010a and the data 1013a indicative of the shapes of the flows and to the connecting line are matched with the data of the vector corresponding to the connected line, and the data 911 of the identification of the flow, the data 912 of the direction of the flow, the data 913 of the input symbol, the data 914 of the output symbol, the data 915 for deciding the result of recognition, and the vector data 918 corresponding to the connected line are stored in the flows table 910. Then, at step 356a, the suitability of the relationship of connection of the symbol as the object of recognition with the partner symbol is investigated on the basis of the relationship recognizing rule 1020a for recognizing the relationship of connection between the symbols as shown in Fig. 9, and the result of recognition is stored in the flows table 910 of Fig. 12 as the data 916 for judging the connection. Thereafter, at step 357a, the partner symbol is stored temporarily in the stack 940 of Fig. 13, followed by returning to the processing at step 352a. It is then investigated to determine if the connecting line connected to the symbol set as the object of recognition further exists, and this processing is repeated until no connecting line exists any more. When it is decided at step 352a that the connected line does not exist any more, on the other hand, then the program flow goes to step 358a at which it is decided to determine if the stack 940 is empty. If even one data of the kind of the symbol is still left in the stack 940, then one symbol indicated by the data of the kind of the symbol is fetched from the diagram recognizing section 25b, and the symbol is set as a symbol as the new object of recognition in step 359a, then the program flow goes back to step 352a. The processing is allowed to end when the stack 940 became vacant. The order of fetching one symbol from the stack 940 may be based on any method, such as a first-in first-out method or a first-in last-out method. Next, a description will now be made of the processing at step 350 in Fig. 10, which employs the recursive processing, with reference to the flowchart as shown in Fig. 14. First, at step 351b, the symbol as the object of recognition delivered as an argument is matched with the symbols recognizing rule 1000a, followed by proceeding to step 352b at which it is decided to determine if the connecting line connected to the symbol as the object of recognition exists. When the result of decision at step 352b indicates that the connected line exists, on the one hand, then the program flow goes to step 353b at which a partner symbol is acquired which exists on the side opposite to the symbol as the object of recognition and beyond the connected line. Then, at step 354b, the partner symbol is matched with the symbols recognizing rule 1000a, followed by proceeding to step 355b at which the direction of the connected line is recognized by the data 1012a indicative of the position of the arrow of the connecting line and the data 1013a indicative of the shapes of the flows in the flows recognizing rule 1013a. Thereafter, at step 356b, the suitability of the relationship of connection between the symbol as the object of recognition and the partner symbol is investigated on the basis of the relationship recognizing rule 1020a indicative of the relationship of connection between the symbols. Then, at step 357b, the partner symbol is assigned to a symbol as a new object of recognition, and the processing for recognizing the symbol and the flow, as shown in Fig. 14, is called in a recursive manner, then returning to the processing at step 352b. When it is found at step 352b that no connecting line to be connected to the symbol as the new object of recognition exists, on the other hand, then this processing is allowed to end. The data stored in the intermediately recognized data storing section 26 by the processing made in the manner as described hereinabove is read by the correction section 27 for correcting the result of recognition, and it is inspected as to whether the data contains any unrecognizable portion. This inspection is conducted on the basis of the data 903 for judging the recognition in the symbols table 900 as shown in Fig. 12, the data 915 for judging the recognition in the flows table 910 as shown in Fig. 12, and the data 922 for judging the recognition in the character string table 920 as shown in Fig. 13. If the symbol, the flow or the character string is represented by "NG", it is displayed on the image display unit 3 requiring the user to make a necessary input recognizable in a correct way. When it is found as a result that there are neither symbol nor flow nor the character string, which is represented by 'NG', the correction section 28 stores the result of correction in the recognized result storing section 28. The result of recognition stored therein is then converted by the recognized result converting section 29 into the logical data, as shown in Fig. 4, which is so adapted as to the data format for the output file 4. As have been described hereinabove, the diagram recognizing system according to the embodiment of the present invention is configured in such a manner that the diagram recognizing rule for recognizing the diagram as the object of recognition is entered from the image display unit 3 and stored in the recognizing rule storing section 25a; the diagram as the object of recognition is then entered as data of an image from the image input unit 1; the symbol, the connecting line, and the character string, each structuring the diagram entered, as well as the relationship of connection between the symbols are recognized on the basis of the recognizing rule by the diagram recognizing section 25b; the symbol, the connecting line, the character string, and the relationship of connection between the symbols are generated as the logical data indicative of the kinds of the symbol and the character string and the relationship of connection between the symbols; and the logical data is converted so as to be generated in such a predetermined text type as being capable of being delivered directly to the CASE tools or the like. Hence, the diagram recognizing system according to the present invention can offer the advantages that it can automatically recognize the diagram formed independently from the CASE tools, that is, the one formed manually or through the drawing software, particularly the one in which the symbols have a directivity in its relationship of connection between the symbols, the positions of the symbols are not determined in advance, and each of the users may define the diagram in an arbitrary manner, and that the logic recognized can be delivered to the CASE tools or the like without the aid of any manual operation. Therefore, the diagram recognizing system according to the present invention enables the operations for entering the diagrams to be reduced in forming the source program through the CASE tools or the like, and the operations for inspecting the adaptability of the diagrams on the basis of the logical contents of the diagram, as well as editing the diagrams, storing them, printing them and converting them into data suitable for the step which follows to be implemented with ease. Further, the diagram recognizing system according to the present invention offers the extremely useful advantage that it can remarkably improve the efficiency in the operations for automatically forming the source program. In addition, the recognizing rule is so adapted as to be entered from the image display unit 3, so that each user can define and modify the recognizing rule with high freedom. This offers the advantage that the optimal recognizing rule can be structured for each user. Further, in recognizing the diagram, the diagram recognizing system according to the present invention is arranged in such a manner that the data of the vector to be determined as a first candidate of the character string is separated; the recognition is allowed to start by setting an aggregate of the data of the vector that has the highest possibility of becoming the diagram as a first candidate of the diagram; the processing is implemented one after another for recognizing the graphic, as a symbol, which exists on the side opposite to the connecting line to be connected to the first candidate of the diagram; and then each of the symbols is recognized so as to correspond to a candidate of the character string provided on the connected line. Hence, the present invention presents the advantage that an error in recognition can be reduced and a high extent of recognition performance can be achieved, as compared with the instance where the symbol and the connecting line are recognized with the character string mixed up therewith. Furthermore, since the unrecognizable portion of the result of recognition can be corrected through the image display unit 3, recognition performance can be improved to a higher extent, and reliability upon the logical data to be generated into the output file 4 can also be improved. In addition, the data of the image of the diagram to be entered from the image input unit 1 is converted into the data of the vector by the data converting section 23 and the diagram is recognized on the basis of the data of the vector, so that a memory capacity of the storing section for storing the image of the diagram can be made smaller and the processing time can be shortened, as compared with the recognition of the image in a pixel unit. It is furthermore to be noted herein that, although the recognizing rule for recognizing the diagram is arranged to be entered through the image display unit 3, it can also be entered through the diagram input means. More specifically, as indicated by the broken line 10 in Fig. 1, the diagram may be entered from the image input unit 1 into the recognizing rule storing section 25a and the recognition of the diagram may be implemented in accordance with pattern matching techniques known to the art. Alternatively, the data of the image of the recognizing rule may be recognized by the diagram recognizing section 25b, the result of recognition may be stored as a recognizing rule, and the diagram may then be recognized in substantially the same operations as described hereinabove. In this case, however, it is required to set another recognizing rule for recognizing the data of the image for the recognizing rule. As shown in Fig. 15 which is the block diagram showing the diagram recognizing system according to the second embodiment of the present invention, the diagram recognizing system may be structured in such a manner that the diagram and the recognizing rule are entered from an input device 11 so arranged as to allow the drawing or the like to be entered through a pen in such data of an image as being capable of being generated in a vector representation. In this case, this arrangement offers the advantages that the structure becomes simpler than the arrangement in the first embodiment of the present invention because neither the image data storing section 22 nor the data converting section 23 are required. Further, the steps for the processing for recognition can be reduced to those as shown in Fig. 16. It is to be noted herein that, as shown in Fig. 16, step 100A denotes the processing for storing the data of the image of the pen input device 11 in the vector data storing section 24; however, the processing at steps 300, 400, and 500 are substantially the same as the corresponding steps as shown in Fig. 2. Hence, a description of the same steps will be omitted from the description that follows. In addition, the entity relationship diagram can be recognized when the recognizing rule is defined in the manner as shown in Figs. 17 to 19, inclusive, although those as shown in Figs. 7 to 9, inclusive, are demonstrated as examples of the recognizing rules. It can be noted herein that the recognizing rules as shown in Figs. 17, 18 and 19 are different from those as shown in Figs. 7, 8 and 9, respectively, in that the recognizing rules are so arranged as to define a composite symbol, as indicated by reference numeral 1006b, as the kind of the symbol, as indicated by "WEAK ENTITY" and a connecting line with no indication of an arrow, as indicated by reference numeral 1016b. It is further to be noted that the reference symbols of the data in Figs. 17, 18 and 19 are provided with a suffix b in place of the suffix a of the reference symbols of the data in Figs. 7, 8 and 9; however, the subject to be defined is the same. It is further to be noted that, for example, even if the user intends to draw a long line as a diagram, it may be recognized as an aggregate of shorter lines when it is converted into data of a vector due to an error or for other reasons. For instance, when a long line is drawn manually in such a manner as being curved to a slight extent, the situation as described hereinabove may happen. In this case, however, a technique for matching the symbol with a recognizing rule using an evaluation point with such an error taken into account may be utilized in order to improve a rate of recognition. This technique may be carried out in the processing for matching the symbol with the recognizing rule at steps 351a and 354a in Fig. 11 and at steps 351b and 354b in Fig. 14. Fig. 20 shows an example of a table 2010 for calculating evaluation points for the symbols recognizing rule 2000. The symbols recognizing rule 2000 contains a column entitled "KIND OF SYMBOLS", as referred to as items such as "external agent", "process", and "file"; a column entitled "CLASSIFICATION", as referred to as items such as "Simple"; a column entitled "SHAPE OF SYMBOL", as referred to, for example, as items such as "the number of long vectors", "a minimum of the number of short vectors", "the number of acute angles", "the number of right angles", "the number of obtuse angles", "the total number of the angles", and "the number of pairs of parallel lines"; a column entitled "POSITION OF CHARACTER STRING", as referred to, for example, as items such as "inside"; a column entitled "DIRECTION OF CHARACTERS", as referred to, for example, as items such as "horizontal"; and a column entitled "CLASS OF GRAPHIC", as referred to, for example, as items such as "closed graphic" or "open graphic". The table 2010 for calculating the evaluation points contains a column 2011 entitled "RECOGNIZING RULES", as referred to, for example, as items such as the number of long vectors, a minimum of the number of short vectors, the number of acute angles, the number of right angles, the number of obtuse angles, the total number of the angles, and the number of pairs of the parallel lines; a column 2012 entitled "SCORES WHEN VALUE OF RECOGNIZING RULE AGREES", and a column 2013 entitled "SCORES TO BE DEDUCTED WHEN RECOGNIZING RULE VARIES BY ONE". In other words, the column 2012 of the table 2010 indicates the score for each of items of the recognizing rule 2011, when the value of the shape of the symbol, as indicated by the column 2001 of the recognizing rule 2000, agrees with a value obtained by quantifying the shape of the graphic. The column 2013 indicates the score for each of the items of the recognizing rule 2011, to be deducted when the value of the recognizing rule varies by one from the value obtained by quantifying the shape of the graphic. Fig. 21 indicates the result of evaluation, as indicated by reference numeral 2110, obtained on the basis of the table 2010 of Fig. 20, for the shape of the graphic as indicated by reference numeral 2100 in Fig. 21. A column 2113 entitled "QUANTIFICATION OF GRAPHIC SHAPE" indicates the result of a column 2111 entitled "RECOGNIZING RULE", which is applied to the shape of the graphic as indicated by reference numeral 2100. In other words, the value 2113 of the quantification of the graphic shape 2100 is such that the number of the long vectors of the recognizing rule 2111 is five; the number of acute angles is two; the number of obtuse angles is three; the total number of the angles is five; and the rest of the items of the recognizing rule is each zero. A column 2114 entitled "EXTERNAL AGENT" contains a sub-column 2115 entitled "DIFFERENCE" and a sub-column 2116 entitled "EVALUATION POINT". The item "DIFFERENCE" of the subcolumn 2115 is a difference between the item 2001, indicative of the shape of the symbol of the symbols recognizing rule 2000 and the quantification 2113 of the shape of the graphic. Accordingly, for example, the number of the obtuse angles in the item 2002 in the symbol shape 2001 of the symbols recognizing rule 2000 in Fig. 20 is defined so as to range from zero to two and the quantification 2113 of the graphic shape indicates the number of the obtuse angles being three, so that the difference as defined in the sub-column 2114 gives one. Hence, the column 2116 "EVALUATION POINT" gives an evaluation point by subtracting the score in the column 2013 from the column 2012. In other words, when the difference 2114 of the number of the obtuse angles is determined as one, as described hereinabove, the evaluation point in the column 2116 of Fig. 21 for the item "number of obtuse angles" in the column 2111 gives '20' by subtracting the score of '10', given by multiplying the score of '10' in the column 2013 with '1' as the value of the difference in the column 2114, from the score of '30' in the column 2012. Hence, the formula in this case may be represented as follows: 30 - 10 x 1 = 20. In the table for the evaluation result, as indicated by reference numeral 2110 in Fig. 21, a column entitled "PROCESS" contains a sub-column entitled "DIFFERENCE" and a sub-column entitled "EVALUATION POINT", and a column entitled "FILE" contains a sub-column entitled "DIFFERENCE" and a sub-column entitled "EVALUATION POINT". The evaluation points for the column "PROCESS" and for the column "FILE" can be calculated in the same manner as described hereinabove. As a result, the highest score in the item "TOTAL OF EVALUATION POINT", as indicated by reference numeral 2117 in Fig. 21, is determined as the result of recognition for the graphic shape 2100. Hence, in this case, the evaluation point of '270' for the external agent is given as the result of recognition for the graphic shape 2100. It can be noted herein that the table 2010 for calculating the evaluation points can give values at improved recognition rates by preparing statistics of examples of actual inputs and setting the values. As have been described hereinabove, the diagram recognizing system according to the present invention is configured in such a manner that the recognizing rule for recognizing the diagram as the object of recognition is entered; the recognizing rule is stored in the recognizing rule storing means; the diagram as the object of recognition is entered as the data of the image; the symbols, the connecting lines, the character string, and the relationship of connection between the symbols, each structuring the diagram entered are recognized by the diagram recognizing means on the basis of the recognizing rule; the kind of each of the symbols, the kind of the character string, and the relationship of connection between the symbols are generated as logical data; and the logical data is converted into such a predetermined file type as being capable of being delivered directly to the CASE tools or the like and generated in such a file format. Hence, the diagram recognizing system according to the present invention can offer the advantages that it can automatically recognize the diagram that is formed, for example, by manual drawing or through a drawing software, in a fashion independent from the CASE tool, particularly the one that has a directivity in the relationship of connection between the symbols, that is not predetermined in terms of its position, and that is defined in an arbitrary manner by each user; and that the logic recognized can be delivered to the CASE tool or the like without the aid of a manual operation. In addition, by adopting the evaluation points for recognizing the shape of the symbol, the diagram recognizing system according to the present invention can further improve recognition rates by adjusting the evaluation points for input data containing an error in manually writing or for other reasons so as to be adapted to the kind of a drawing or writing device used for drawing the diagram, the width of lines, the quality of paper, a writing habit of an individual writer, or the like. Hence, the diagram recognizing system according to the present invention can reduce the operations for entering the diagrams upon the formation of a source program through the CASE tool or the like and readily implement the processing for investigating the adaptability on the basis of the logical contents of the diagrams and for editing the diagrams, storing them, printing them, and converting them to data processible in the steps which follow, thereby offering the extremely useful result that it can improve efficiency in the operations for automatically preparing the source program. Furthermore, the diagram recognizing system according to the present invention presents the effect that the optimal recognizing rule can be structured for each user because the recognizing rule can be defined and altered by each user with high freedom.

Claims: A diagram recognizing system comprising: a diagram input means (1, 21) for entering a diagram for describing a specification for data processing, such as a flowchart or a data flow diagram as data of an image, said diagram including a symbol represented by a graphic, such as a circle, a rectangle, and so on, a connecting line connecting symbols and having a directivity, and a character string provided on the symbol and the connecting line, a recognizing rules input means (3) for entering a symbol recognizing rule (1000a) including a kind of symbol, a classification of symbol, a shape of symbol; a flow recognizing rule (1010a) which describes a position of an arrow mark, a shape of a flow; a relationship recognizing rule (1020a) which describes the logical relationship of connection acceptable between the two symbols; a recognizing rules storing means (25a) for storing said recognizing rules entered from the recognizing rule input means; a diagram recognizing means (25b) for recognizing the symbol, the connecting line, the character string, and a logical relationship of connection acceptable between the two symbols, each structuring the diagram entered from the diagram input means (1, 21) on the basis of said recognizing rules stored by the recognizing rules storing means (25a), and for generating the symbol, the connecting line, the character string, and the relationship of connection between the symbols as logical data, indicative of a kind of each of the symbols, a kind of the character string, and the relationhip of connection between the symbols; and conversion means (29) for converting the logical data generated from the diagram recognizing means into a predetermined file format. A diagram recognizing system as claimed in claim 1, further comprising a correction means (3, 27) through which a user can define and/or modify the recognizing rules. A diagram recognizing system as claimed in claim 1 or 2, wherein the diagram input means (1) comprises an image reader. A diagram recognizing system as claimed in one of the preceding claims, wherein the diagram input means comprises a pen input device (11) capable of generating a graphic as drawn with a pen or the like as the data of the image. A diagram recognizing system as claimed in one of the preceding claims, wherein the diagram input means (1) is so adapted as to enter (10) the recognizing rule, in addition of a function as entering the diagram. A diagram recognizing system as claimed in one of the preceding claims, further comprising an image data converting means (23) for converting the data of the image entered from the diagram input means (1, 21) into data of an image in a vector representation and for entering the data of the image into the diagram recognizing means. A diagram recognizing method comprising the steps of: reading a diagram for describing a specification for data processing, such as a flowchart or a data flow diagram as data of an image, said diagram including a symbol represented by a graphic, such as a circle, a rectangle, and so on, a connecting line connecting symbols and having a directivity, and a character string provided on the symbol and the connecting line, reading a symbol recognizing rule (1000a) including a kind of symbol, a classification of symbol, a shape of symbol; reading a flow recognizing rule (1010a) which describes a position of an arrow mark, a shape of a flow; reading a relationship recognizing rule (1020a) which describes the logical relationship of connection acceptable between the two symbols; recognizing the symbol, the connecting line, the character string, and a logical relationship of connection acceptable between the two symbols, each structuring the diagram entered from the diagram input means (1, 21) on the basis of said recognizing rules stored by the recognizing rules storing means (25a), generating the symbol, the connecting line, the character string, and the relationship of connection between the symbols as logical data, indicative of a kind of each of the symbols, a kind of the character string, and the relationship of connection between the symbols; and converting the logical data generated from the diagram recognizing means into a predetermined file format. A diagram recognizing method according to claim 7, wherein the step of recognizing comprises: separating (330) candidates of character strings from the diagram by a length of line segments in the diagram; selecting (340) closed graphic symbols in the diagram as the first symbol to be recognized; determining (352a) whether or not a connecting line to a symbol as object of recognition exists, acquiring (353a) a partner symbol at the other end of the connecting line, recognizing (355a) a direction of the connecting line between the symbol and the partner symbol; assigning (360, 370) the candidate of character strings to the recognized symbols and/or connecting lines; recognizing (380) the candidate of character strings. A diagram recognizing system as claimed in claim 1, wherein said diagram recognizing means determines the suitable symbol corresponding to each graphic of diagram on basis of an evaluation point of the graphic, said evaluation point being defined by recognizing a vector length as being in a predetermined range, an acute angle and an obtuse angle of the graphic, the total number of corners of the graphic and the number of pairs of parallel lines of the graphic indicative of the features of the shape of the symbol, to thereby calculate the evaluation point.

Inventors: KANO SHIGERU, NAKADA YASUHIRO, USUDA YUTAKA, KANO, SHIGERU, NAKADA, YASUHIRO, USUDA, YUTAKA, KANO, SHIGERU, HITACHI SOFT YOKOHAMA RYO
Applicants: HITACHI SOFTWARE ENG, HITACHI SOFTWARE ENGINEERING CO., LTD.
Application year: 1992
Main classification: G06K9
IPC codes: G06K9, G06F17, G06T7, G06F9