{"id":{"repo_id":"greece","oai_identifier":"oai:10442/1188"},"canonical_url":"https://search.dev.ndltd.org/etd/greece/oai:10442/1188","repository":{"repo_id":"greece","name":"Greek National Archive of PhD Theses","base_url":"https://phdtheses.ekt.gr/eadd_oai/request"},"display":{"title":"SCAN: ΜΙΑ ΓΛΩΣΣΑ ΓΙΑ ΑΚΟΛΟΥΘΙΑΚΗ ΠΡΟΣΠΕΛΑΣΗ ΔΙΔΙΑΣΤΑΤΩΝ ΔΕΔΟΜΕΝΩΝ","abstract":"THE MAIN OBJECTIVE OF THIS WORK IS THE PRESENTATION AND THE DEVELOPMENT OF A NEW, SPECIAL PURPOSE LANGUAGE, CALLED SCAN LANGUAGE. THE DEVELOPMENT OF SCAN PROVIDES AN EFFICIENT APPROACH TO THE FOLLOWING PROBLEM: \"GIVEN AN IMAGE ARRAY P OFNXN ELEMENTS, DEVELOP A TOOL WHICH CAN DESCRIBE AND PRODUCE ALL POSSIBLE SCANNING SEQUENCES OF P (THAT IS (N2)! DIFFERENT SEQUENCES)\". SCAN IS A SIMPLE CONTEXT-FREE LANGUAGE DEVOTED TO DESCRIBE AND GENERATE A WIDE RANGE OF TWO DIMENTIONAL ARRAY ACCESSING ALGORITHMS FROM A SHORT SET OF SIMPLE AND FUNDAMENTAL ONES, WHICH ARE DEFINED AS ELEMENTS OF THE SCAN ALPHABET. THE ALGORITHMS GENERATED BYSCAN MAY REPRESENT SCANNING TECHNIQUES FOR IMAGE PROCESSING, OR FOR IMAGE ENCODING, BUT AT THE SAME TIME THEY STAND AS GENERIC 2-D DATA ACCESSING STRATEGIES.IN THIS DISSERTATION A FORMAL DEFINITION OF SCAN IS FIRST GIVEN, BY PRESENTINGTHE SYNTACTICAL AND SEMANTIC ISSUES OF THE LANGUAGE. ITS UNDERLYING MATHEMATICAL MODEL AND GENERAL PROPERTIES ARE NEXT GIVEN. THE ALGEBRAIC STRUCTURE OF THE DOMAIN OF THE GENERATED SCAN PATTERNS IS ALSO INVESTIGATED. AFTER PROPOSING A SPECIFIC SCAN ALPHABET, SOME INTERESTING PROPERTIES OF THE GENERATED SCAN PATTERNS ARE FORMULATED. TWO IMPLEMENTATION SCHEMES OF SCAN BASED ON THAT SPECIFIC ALPHABET ARE NEXT PRESENTED AND COMPARED. AN EXTENSION OF THE SCAN LANGUAGE FEATURING THE CAPABILITY OF GENERATING A LARGE FAMILY OF RECURSIVE SCANS IS ALSO SPECIFIED AND PROPOSED TO BE A MATTER FOR FUTURE WORK. FURTHERMORE, FOR THE PURPOSE OF DEMONSTRATING THE APPLICABILITY OF THE LANGUAGE IN THE IMAGE PROCESSING AREA, SOME APPLICATIONS OF SCAN ARE PRESENTED. THE FIRST APPLICATION IS BASED ON THE HIERARCHICAL NATURE OF THE SCAN PATTERNS: THE APPLICATION OF A SCAN PATTERNON AN IMAGE ARRAY PROVIDES THE IMAGE ELEMENTS IN SUCH AN ORDER, SO THAT THE IMPLEMENTATION OF HIERARCHICAL IMAGE ELEMENTS IN SUCH AN ORDER, SO THAT THE IMPLEMENTATION OF HIERARCHICAL IMAGE DATA STRUCTURES (PYRAMIDS, QUADTREES) COULD BE DONE IN A SIMPLE AND EFFICIENT WAY, WITHOUT MEMORY OVERHEAD. THE CONSTRUCTION OF SUCH A STRUCTURE (T-PYRAMID) IS SHOWN. A SECOND APPLICATION REFERS ON THE SEQUENTIAL SYNTHESIS OF 2-D TEXTURE PATTERNS. IN PARTICULAR, A VARIATION OF THE SCAN MECHANISM WHICH CAN PRODUCE TEXTURE PATTERNS IS PRESENTED. FINALLY, A 2-D DATA ENCRYPTION SCHEME BASED ON SCAN PATTERNS IS PRESENTED AND DISCUSSED.","abstract_html":"THE MAIN OBJECTIVE OF THIS WORK IS THE PRESENTATION AND THE DEVELOPMENT OF A NEW, SPECIAL PURPOSE LANGUAGE, CALLED SCAN LANGUAGE. THE DEVELOPMENT OF SCAN PROVIDES AN EFFICIENT APPROACH TO THE FOLLOWING PROBLEM: "GIVEN AN IMAGE ARRAY P OFNXN ELEMENTS, DEVELOP A TOOL WHICH CAN DESCRIBE AND PRODUCE ALL POSSIBLE SCANNING SEQUENCES OF P (THAT IS (N2)! DIFFERENT SEQUENCES)". SCAN IS A SIMPLE CONTEXT-FREE LANGUAGE DEVOTED TO DESCRIBE AND GENERATE A WIDE RANGE OF TWO DIMENTIONAL ARRAY ACCESSING ALGORITHMS FROM A SHORT SET OF SIMPLE AND FUNDAMENTAL ONES, WHICH ARE DEFINED AS ELEMENTS OF THE SCAN ALPHABET. THE ALGORITHMS GENERATED BYSCAN MAY REPRESENT SCANNING TECHNIQUES FOR IMAGE PROCESSING, OR FOR IMAGE ENCODING, BUT AT THE SAME TIME THEY STAND AS GENERIC 2-D DATA ACCESSING STRATEGIES.IN THIS DISSERTATION A FORMAL DEFINITION OF SCAN IS FIRST GIVEN, BY PRESENTINGTHE SYNTACTICAL AND SEMANTIC ISSUES OF THE LANGUAGE. ITS UNDERLYING MATHEMATICAL MODEL AND GENERAL PROPERTIES ARE NEXT GIVEN. THE ALGEBRAIC STRUCTURE OF THE DOMAIN OF THE GENERATED SCAN PATTERNS IS ALSO INVESTIGATED. AFTER PROPOSING A SPECIFIC SCAN ALPHABET, SOME INTERESTING PROPERTIES OF THE GENERATED SCAN PATTERNS ARE FORMULATED. TWO IMPLEMENTATION SCHEMES OF SCAN BASED ON THAT SPECIFIC ALPHABET ARE NEXT PRESENTED AND COMPARED. AN EXTENSION OF THE SCAN LANGUAGE FEATURING THE CAPABILITY OF GENERATING A LARGE FAMILY OF RECURSIVE SCANS IS ALSO SPECIFIED AND PROPOSED TO BE A MATTER FOR FUTURE WORK. FURTHERMORE, FOR THE PURPOSE OF DEMONSTRATING THE APPLICABILITY OF THE LANGUAGE IN THE IMAGE PROCESSING AREA, SOME APPLICATIONS OF SCAN ARE PRESENTED. THE FIRST APPLICATION IS BASED ON THE HIERARCHICAL NATURE OF THE SCAN PATTERNS: THE APPLICATION OF A SCAN PATTERNON AN IMAGE ARRAY PROVIDES THE IMAGE ELEMENTS IN SUCH AN ORDER, SO THAT THE IMPLEMENTATION OF HIERARCHICAL IMAGE ELEMENTS IN SUCH AN ORDER, SO THAT THE IMPLEMENTATION OF HIERARCHICAL IMAGE DATA STRUCTURES (PYRAMIDS, QUADTREES) COULD BE DONE IN A SIMPLE AND EFFICIENT WAY, WITHOUT MEMORY OVERHEAD. THE CONSTRUCTION OF SUCH A STRUCTURE (T-PYRAMID) IS SHOWN. A SECOND APPLICATION REFERS ON THE SEQUENTIAL SYNTHESIS OF 2-D TEXTURE PATTERNS. IN PARTICULAR, A VARIATION OF THE SCAN MECHANISM WHICH CAN PRODUCE TEXTURE PATTERNS IS PRESENTED. FINALLY, A 2-D DATA ENCRYPTION SCHEME BASED ON SCAN PATTERNS IS PRESENTED AND DISCUSSED.","abstract_has_math":false,"creators":["Αλεξόπουλος, Χρήστος"],"institution":"Πανεπιστήμιο Πατρών","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1989,"date_issued":"1989","date_published":"1989","updated_at":"2026-07-24T02:24:46Z","subjects":["CONTEXT-FREE LANGUAGES","GENERATION (OR IMPLEMENTATION) OF TREE-PYRAMIDS","HIERARCHICAL IMAGEDATA STRUCTURES","IMAGE SCANNING TECHNIQUES","Parallel implementation","PICTURE PROCESSING","R-D DATA ENCRYPTION","RECURSIVE ACCESSING TECHNIQUES","TEXTURE PATTERN GENERATION","ΑΝΑΔΡΟΜΙΚΕΣ ΤΕΧΝΙΚΕΣ ΠΡΟΣΠΕΛΑΣΗΣ ΔΕΔΟΜΕΝΩΝ","ΓΛΩΣΣΕΣ ΑΝΕΞΑΡΤΗΤΕΣ ΠΕΡΙΕΧΟΜΕΝΟΥ","ΔΗΜΙΟΥΡΓΙΑ TEXTURE ΕΙΚΟΝΑΣ","ΔΗΜΙΟΥΡΓΙΑ ΔΕΝΔΡΙΚΩΝ ΠΥΡΑΜΙΔΩΝ ΕΙΚΟΝΑΣ","Επεξεργασία εικόνας","ΙΕΡΑΡΧΙΚΕΣ ΔΟΜΕΣ ΔΕΔΟΜΕΝΩΝ ΕΙΚΟΝΑΣ","ΚΡΥΠΤΟΓΡΑΦΗΣΗ ΔΙΔΙΑΣΤΑΤΩΝ ΔΕΔΟΜΕΝΩΝ","ΠΑΡΑΛΛΗΛΗ ΥΛΟΠΟΙΗΣΗ","ΤΕΧΝΙΚΕΣ ΣΑΡΩΣΗΣ ΕΙΚΟΝΑΣ","Natural Sciences","Computer and Information Sciences","Engineering and Technology","Electrical Engineering, Electronic Engineering, Information Engineering","Φυσικές Επιστήμες","Επιστήμη Ηλεκτρονικών Υπολογιστών και Πληροφορική","Επιστήμες Μηχανικού και Τεχνολογία","Επιστήμη Ηλεκτρολόγου Μηχανικού, Ηλεκτρονικού Μηχανικού, Μηχανικού Η/Υ"],"languages":["gre"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["10.12681/eadd/1188"],"render_values":[{"text":"10.12681/eadd/1188","href":"https://doi.org/10.12681/eadd/1188","code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10442/hedi/1188","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Αλεξόπουλος, Χρήστος"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["1989"]},{"key":"dc:publisher","label":"Institution","values":["Πανεπιστήμιο Πατρών","University of Patras"]},{"key":"dc:type","label":"Dc Type","values":["PhD Thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["CONTEXT-FREE LANGUAGES","GENERATION (OR IMPLEMENTATION) OF TREE-PYRAMIDS","HIERARCHICAL IMAGEDATA STRUCTURES","IMAGE SCANNING TECHNIQUES","Parallel implementation","PICTURE PROCESSING","R-D DATA ENCRYPTION","RECURSIVE ACCESSING TECHNIQUES","TEXTURE PATTERN GENERATION","ΑΝΑΔΡΟΜΙΚΕΣ ΤΕΧΝΙΚΕΣ ΠΡΟΣΠΕΛΑΣΗΣ ΔΕΔΟΜΕΝΩΝ","ΓΛΩΣΣΕΣ ΑΝΕΞΑΡΤΗΤΕΣ ΠΕΡΙΕΧΟΜΕΝΟΥ","ΔΗΜΙΟΥΡΓΙΑ TEXTURE ΕΙΚΟΝΑΣ","ΔΗΜΙΟΥΡΓΙΑ ΔΕΝΔΡΙΚΩΝ ΠΥΡΑΜΙΔΩΝ ΕΙΚΟΝΑΣ","Επεξεργασία εικόνας","ΙΕΡΑΡΧΙΚΕΣ ΔΟΜΕΣ ΔΕΔΟΜΕΝΩΝ ΕΙΚΟΝΑΣ","ΚΡΥΠΤΟΓΡΑΦΗΣΗ ΔΙΔΙΑΣΤΑΤΩΝ ΔΕΔΟΜΕΝΩΝ","ΠΑΡΑΛΛΗΛΗ ΥΛΟΠΟΙΗΣΗ","ΤΕΧΝΙΚΕΣ ΣΑΡΩΣΗΣ ΕΙΚΟΝΑΣ","Natural Sciences","Computer and Information Sciences","Engineering and Technology","Electrical Engineering, Electronic Engineering, Information Engineering","Φυσικές Επιστήμες","Επιστήμη Ηλεκτρονικών Υπολογιστών και Πληροφορική","Επιστήμες Μηχανικού και Τεχνολογία","Επιστήμη Ηλεκτρολόγου Μηχανικού, Ηλεκτρονικού Μηχανικού, Μηχανικού Η/Υ"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["gre"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["10.12681/eadd/1188","http://hdl.handle.net/10442/hedi/1188"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["THE MAIN OBJECTIVE OF THIS WORK IS THE PRESENTATION AND THE DEVELOPMENT OF A NEW, SPECIAL PURPOSE LANGUAGE, CALLED SCAN LANGUAGE. THE DEVELOPMENT OF SCAN PROVIDES AN EFFICIENT APPROACH TO THE FOLLOWING PROBLEM: \"GIVEN AN IMAGE ARRAY P OFNXN ELEMENTS, DEVELOP A TOOL WHICH CAN DESCRIBE AND PRODUCE ALL POSSIBLE SCANNING SEQUENCES OF P (THAT IS (N2)! DIFFERENT SEQUENCES)\". SCAN IS A SIMPLE CONTEXT-FREE LANGUAGE DEVOTED TO DESCRIBE AND GENERATE A WIDE RANGE OF TWO DIMENTIONAL ARRAY ACCESSING ALGORITHMS FROM A SHORT SET OF SIMPLE AND FUNDAMENTAL ONES, WHICH ARE DEFINED AS ELEMENTS OF THE SCAN ALPHABET. THE ALGORITHMS GENERATED BYSCAN MAY REPRESENT SCANNING TECHNIQUES FOR IMAGE PROCESSING, OR FOR IMAGE ENCODING, BUT AT THE SAME TIME THEY STAND AS GENERIC 2-D DATA ACCESSING STRATEGIES.IN THIS DISSERTATION A FORMAL DEFINITION OF SCAN IS FIRST GIVEN, BY PRESENTINGTHE SYNTACTICAL AND SEMANTIC ISSUES OF THE LANGUAGE. ITS UNDERLYING MATHEMATICAL MODEL AND GENERAL PROPERTIES ARE NEXT GIVEN. THE ALGEBRAIC STRUCTURE OF THE DOMAIN OF THE GENERATED SCAN PATTERNS IS ALSO INVESTIGATED. AFTER PROPOSING A SPECIFIC SCAN ALPHABET, SOME INTERESTING PROPERTIES OF THE GENERATED SCAN PATTERNS ARE FORMULATED. TWO IMPLEMENTATION SCHEMES OF SCAN BASED ON THAT SPECIFIC ALPHABET ARE NEXT PRESENTED AND COMPARED. AN EXTENSION OF THE SCAN LANGUAGE FEATURING THE CAPABILITY OF GENERATING A LARGE FAMILY OF RECURSIVE SCANS IS ALSO SPECIFIED AND PROPOSED TO BE A MATTER FOR FUTURE WORK. FURTHERMORE, FOR THE PURPOSE OF DEMONSTRATING THE APPLICABILITY OF THE LANGUAGE IN THE IMAGE PROCESSING AREA, SOME APPLICATIONS OF SCAN ARE PRESENTED. THE FIRST APPLICATION IS BASED ON THE HIERARCHICAL NATURE OF THE SCAN PATTERNS: THE APPLICATION OF A SCAN PATTERNON AN IMAGE ARRAY PROVIDES THE IMAGE ELEMENTS IN SUCH AN ORDER, SO THAT THE IMPLEMENTATION OF HIERARCHICAL IMAGE ELEMENTS IN SUCH AN ORDER, SO THAT THE IMPLEMENTATION OF HIERARCHICAL IMAGE DATA STRUCTURES (PYRAMIDS, QUADTREES) COULD BE DONE IN A SIMPLE AND EFFICIENT WAY, WITHOUT MEMORY OVERHEAD. THE CONSTRUCTION OF SUCH A STRUCTURE (T-PYRAMID) IS SHOWN. A SECOND APPLICATION REFERS ON THE SEQUENTIAL SYNTHESIS OF 2-D TEXTURE PATTERNS. IN PARTICULAR, A VARIATION OF THE SCAN MECHANISM WHICH CAN PRODUCE TEXTURE PATTERNS IS PRESENTED. FINALLY, A 2-D DATA ENCRYPTION SCHEME BASED ON SCAN PATTERNS IS PRESENTED AND DISCUSSED.","Ο ΚΥΡΙΟΣ ΣΤΟΧΟΣ ΤΗΣ ΕΡΓΑΣΙΑΣ ΑΥΤΗΣ ΕΙΝΑΙ Η ΠΑΡΟΥΣΙΑΣΗ ΚΑΙ Η ΑΝΑΠΤΥΞΗ ΜΙΑΣ ΝΕΑΣ ΓΛΩΣΣΑΣ ΕΙΔΙΚΟΥ ΣΚΟΠΟΥ, ΤΗΣ ΓΛΩΣΣΑΣ SCAN. Η SCAN ΕΙΝΑΙ ΜΙΑ ΑΠΛΗ ΚΑΙ ΑΝΕΞΑΡΤΗΤΗ ΠΕΡΙΕΧΟΜΕΝΟΥ (CONTEXT-FREE) ΓΛΩΣΣΑ, ΙΚΑΝΗ ΝΑ ΠΕΡΙΓΡΑΨΕΙ ΚΑΙ ΝΑ ΠΑΡΑΓΕΙ ΕΝΑ ΜΕΓΑΛΟ ΑΡΙΘΜΟ ΑΛΓΟΡΙΘΜΩΝ ΠΡΟΣΠΕΛΑΣΗΣ ('Η ΣΑΡΩΣΗΣ) ΕΝΟΣ ΔΙΔΙΑΣΤΑΤΟΥ ΠΙΝΑΚΑ, ΟΙ ΟΠΟΙΟΙ ΣΥΝΘΕΤΟΝΤΑΙ ΑΠΟ ΕΝΑ ΜΙΚΡΟ ΣΥΝΟΛΟ ΑΠΛΩΝ ΑΛΓΟΡΙΘΜΩΝ ΒΑΣΗΣ. ΟΙ ΤΕΛΕΥΤΑΙΟΙ ΑΠΟΤΕΛΟΥΝ ΤΟ ΑΛΦΑΒΗΤΟ ΤΗΣ ΓΛΩΣΣΑΣ. ΟΙ ΑΛΓΟΡΙΘΜΟΙ ΠΟΥ ΠΑΡΑΓΟΝΤΑΙ ΑΠΟ ΤΗΝ SCAN ΜΠΟΡΟΥΝ ΝΑ ΑΝΑΠΑΡΑΣΤΗΣΟΥΝ ΤΕΧΝΙΚΕΣ ΣΑΡΩΣΗΣ ΓΙΑ ΤΗΝ ΕΠΕΞΕΡΓΑΣΙΑ ΜΙΑΣ ΨΗΦΙΑΚΗΣ ΕΙΚΟΝΑΣ, 'Η ΓΙΑ ΤΗΝ ΚΩΔΙΚΟΠΟΙΗΣΗ ΕΙΚΟΝΑΣ, ΑΛΛΑ ΤΑΥΤΟΧΡΟΝΑ ΑΠΟΤΕΛΟΥΝ ΓΕΝΙΚΕΥΜΕΝΕΣ ΤΕΧΝΙΚΕΣΑΚΟΛΟΥΘΙΑΚΗΣ ΠΡΟΣΠΕΛΑΣΗΣ ΔΙΔΙΑΣΤΑΤΩΝ ΔΕΔΟΜΕΝΩΝ. ΣΤΗΝ ΠΑΡΟΥΣΙΑΖΟΜΕΝΗ ΔΙΑΤΡΙΒΗ ΠΑΡΟΥΣΙΑΖΕΤΑΙ Ο ΤΥΠΙΚΟΣ ΚΑΘΟΡΙΣΜΟΣ ΤΗΣ ΓΛΩΣΣΑΣ SCAN. ΔΙΝΟΝΤΑΙ ΕΠΙΣΗΣ ΤΟ ΜΑΘΗΜΑΤΙΚΟ ΤΗΣ ΜΟΝΤΕΛΟ, ΟΙ ΓΕΝΙΚΕΣ ΤΗΣ ΙΔΙΟΤΗΤΕΣ, ΚΑΙ ΕΡΕΥΝΑΤΑΙ Η ΑΛΓΕΒΡΙΚΗ ΔΟΜΗ ΤΟΥ ΧΩΡΟΥ ΤΩΝ ΠΑΡΑΓΟΜΕΝΩΝ SCAN ΑΚΟΛΟΥΘΙΩΝ, ΠΟΥ ΟΠΩΣ ΔΕΙΧΝΕΤΑΙ ΕΙΝΑΙ ΕΝΑ ΜΟΝΟΕΙΔΕΣ. ΜΕΤΗΝ ΠΡΟΤΑΣΗ ΕΝΟΣ ΣΥΓΚΕΚΡΙΜΕΝΟΥ SCAN ΑΛΦΑΒΗΤΟΥ, ΠΟΥ ΑΠΟΤΕΛΕΙΤΑΙ ΑΠΟ ΔΙΑΔΕΔΟΜΕΝΕΣ ΚΑΙ ΑΠΛΕΣ ΤΕΧΝΙΚΕΣ ΣΑΡΩΣΗΣ, ΔΙΑΤΥΠΩΝΟΝΤΑΙ ΜΕΡΙΚΕΣ ΕΝΔΙΑΦΕΡΟΥΣΕΣ ΙΔΙΟΤΗΤΕΣ ΤΩΝΠΑΡΑΓΟΜΕΝΩΝ SCAN ΠΡΟΤΥΠΩΝ. (ΠΕΡΙΚΟΠΗ)"]},{"key":"dc:title","label":"Title","values":["SCAN: ΜΙΑ ΓΛΩΣΣΑ ΓΙΑ ΑΚΟΛΟΥΘΙΑΚΗ ΠΡΟΣΠΕΛΑΣΗ ΔΙΔΙΑΣΤΑΤΩΝ ΔΕΔΟΜΕΝΩΝ","SCAN: A LANGUAGE FOR TWO DIMENSIONAL DATA ACCESSING"]}]}],"canonical_facts":{"dc:creator":["Αλεξόπουλος, Χρήστος"],"dc:date":["1989"],"dc:description":["THE MAIN OBJECTIVE OF THIS WORK IS THE PRESENTATION AND THE DEVELOPMENT OF A NEW, SPECIAL PURPOSE LANGUAGE, CALLED SCAN LANGUAGE. THE DEVELOPMENT OF SCAN PROVIDES AN EFFICIENT APPROACH TO THE FOLLOWING PROBLEM: \"GIVEN AN IMAGE ARRAY P OFNXN ELEMENTS, DEVELOP A TOOL WHICH CAN DESCRIBE AND PRODUCE ALL POSSIBLE SCANNING SEQUENCES OF P (THAT IS (N2)! DIFFERENT SEQUENCES)\". SCAN IS A SIMPLE CONTEXT-FREE LANGUAGE DEVOTED TO DESCRIBE AND GENERATE A WIDE RANGE OF TWO DIMENTIONAL ARRAY ACCESSING ALGORITHMS FROM A SHORT SET OF SIMPLE AND FUNDAMENTAL ONES, WHICH ARE DEFINED AS ELEMENTS OF THE SCAN ALPHABET. THE ALGORITHMS GENERATED BYSCAN MAY REPRESENT SCANNING TECHNIQUES FOR IMAGE PROCESSING, OR FOR IMAGE ENCODING, BUT AT THE SAME TIME THEY STAND AS GENERIC 2-D DATA ACCESSING STRATEGIES.IN THIS DISSERTATION A FORMAL DEFINITION OF SCAN IS FIRST GIVEN, BY PRESENTINGTHE SYNTACTICAL AND SEMANTIC ISSUES OF THE LANGUAGE. ITS UNDERLYING MATHEMATICAL MODEL AND GENERAL PROPERTIES ARE NEXT GIVEN. THE ALGEBRAIC STRUCTURE OF THE DOMAIN OF THE GENERATED SCAN PATTERNS IS ALSO INVESTIGATED. AFTER PROPOSING A SPECIFIC SCAN ALPHABET, SOME INTERESTING PROPERTIES OF THE GENERATED SCAN PATTERNS ARE FORMULATED. TWO IMPLEMENTATION SCHEMES OF SCAN BASED ON THAT SPECIFIC ALPHABET ARE NEXT PRESENTED AND COMPARED. AN EXTENSION OF THE SCAN LANGUAGE FEATURING THE CAPABILITY OF GENERATING A LARGE FAMILY OF RECURSIVE SCANS IS ALSO SPECIFIED AND PROPOSED TO BE A MATTER FOR FUTURE WORK. FURTHERMORE, FOR THE PURPOSE OF DEMONSTRATING THE APPLICABILITY OF THE LANGUAGE IN THE IMAGE PROCESSING AREA, SOME APPLICATIONS OF SCAN ARE PRESENTED. THE FIRST APPLICATION IS BASED ON THE HIERARCHICAL NATURE OF THE SCAN PATTERNS: THE APPLICATION OF A SCAN PATTERNON AN IMAGE ARRAY PROVIDES THE IMAGE ELEMENTS IN SUCH AN ORDER, SO THAT THE IMPLEMENTATION OF HIERARCHICAL IMAGE ELEMENTS IN SUCH AN ORDER, SO THAT THE IMPLEMENTATION OF HIERARCHICAL IMAGE DATA STRUCTURES (PYRAMIDS, QUADTREES) COULD BE DONE IN A SIMPLE AND EFFICIENT WAY, WITHOUT MEMORY OVERHEAD. THE CONSTRUCTION OF SUCH A STRUCTURE (T-PYRAMID) IS SHOWN. A SECOND APPLICATION REFERS ON THE SEQUENTIAL SYNTHESIS OF 2-D TEXTURE PATTERNS. IN PARTICULAR, A VARIATION OF THE SCAN MECHANISM WHICH CAN PRODUCE TEXTURE PATTERNS IS PRESENTED. FINALLY, A 2-D DATA ENCRYPTION SCHEME BASED ON SCAN PATTERNS IS PRESENTED AND DISCUSSED.","Ο ΚΥΡΙΟΣ ΣΤΟΧΟΣ ΤΗΣ ΕΡΓΑΣΙΑΣ ΑΥΤΗΣ ΕΙΝΑΙ Η ΠΑΡΟΥΣΙΑΣΗ ΚΑΙ Η ΑΝΑΠΤΥΞΗ ΜΙΑΣ ΝΕΑΣ ΓΛΩΣΣΑΣ ΕΙΔΙΚΟΥ ΣΚΟΠΟΥ, ΤΗΣ ΓΛΩΣΣΑΣ SCAN. Η SCAN ΕΙΝΑΙ ΜΙΑ ΑΠΛΗ ΚΑΙ ΑΝΕΞΑΡΤΗΤΗ ΠΕΡΙΕΧΟΜΕΝΟΥ (CONTEXT-FREE) ΓΛΩΣΣΑ, ΙΚΑΝΗ ΝΑ ΠΕΡΙΓΡΑΨΕΙ ΚΑΙ ΝΑ ΠΑΡΑΓΕΙ ΕΝΑ ΜΕΓΑΛΟ ΑΡΙΘΜΟ ΑΛΓΟΡΙΘΜΩΝ ΠΡΟΣΠΕΛΑΣΗΣ ('Η ΣΑΡΩΣΗΣ) ΕΝΟΣ ΔΙΔΙΑΣΤΑΤΟΥ ΠΙΝΑΚΑ, ΟΙ ΟΠΟΙΟΙ ΣΥΝΘΕΤΟΝΤΑΙ ΑΠΟ ΕΝΑ ΜΙΚΡΟ ΣΥΝΟΛΟ ΑΠΛΩΝ ΑΛΓΟΡΙΘΜΩΝ ΒΑΣΗΣ. ΟΙ ΤΕΛΕΥΤΑΙΟΙ ΑΠΟΤΕΛΟΥΝ ΤΟ ΑΛΦΑΒΗΤΟ ΤΗΣ ΓΛΩΣΣΑΣ. ΟΙ ΑΛΓΟΡΙΘΜΟΙ ΠΟΥ ΠΑΡΑΓΟΝΤΑΙ ΑΠΟ ΤΗΝ SCAN ΜΠΟΡΟΥΝ ΝΑ ΑΝΑΠΑΡΑΣΤΗΣΟΥΝ ΤΕΧΝΙΚΕΣ ΣΑΡΩΣΗΣ ΓΙΑ ΤΗΝ ΕΠΕΞΕΡΓΑΣΙΑ ΜΙΑΣ ΨΗΦΙΑΚΗΣ ΕΙΚΟΝΑΣ, 'Η ΓΙΑ ΤΗΝ ΚΩΔΙΚΟΠΟΙΗΣΗ ΕΙΚΟΝΑΣ, ΑΛΛΑ ΤΑΥΤΟΧΡΟΝΑ ΑΠΟΤΕΛΟΥΝ ΓΕΝΙΚΕΥΜΕΝΕΣ ΤΕΧΝΙΚΕΣΑΚΟΛΟΥΘΙΑΚΗΣ ΠΡΟΣΠΕΛΑΣΗΣ ΔΙΔΙΑΣΤΑΤΩΝ ΔΕΔΟΜΕΝΩΝ. ΣΤΗΝ ΠΑΡΟΥΣΙΑΖΟΜΕΝΗ ΔΙΑΤΡΙΒΗ ΠΑΡΟΥΣΙΑΖΕΤΑΙ Ο ΤΥΠΙΚΟΣ ΚΑΘΟΡΙΣΜΟΣ ΤΗΣ ΓΛΩΣΣΑΣ SCAN. ΔΙΝΟΝΤΑΙ ΕΠΙΣΗΣ ΤΟ ΜΑΘΗΜΑΤΙΚΟ ΤΗΣ ΜΟΝΤΕΛΟ, ΟΙ ΓΕΝΙΚΕΣ ΤΗΣ ΙΔΙΟΤΗΤΕΣ, ΚΑΙ ΕΡΕΥΝΑΤΑΙ Η ΑΛΓΕΒΡΙΚΗ ΔΟΜΗ ΤΟΥ ΧΩΡΟΥ ΤΩΝ ΠΑΡΑΓΟΜΕΝΩΝ SCAN ΑΚΟΛΟΥΘΙΩΝ, ΠΟΥ ΟΠΩΣ ΔΕΙΧΝΕΤΑΙ ΕΙΝΑΙ ΕΝΑ ΜΟΝΟΕΙΔΕΣ. ΜΕΤΗΝ ΠΡΟΤΑΣΗ ΕΝΟΣ ΣΥΓΚΕΚΡΙΜΕΝΟΥ SCAN ΑΛΦΑΒΗΤΟΥ, ΠΟΥ ΑΠΟΤΕΛΕΙΤΑΙ ΑΠΟ ΔΙΑΔΕΔΟΜΕΝΕΣ ΚΑΙ ΑΠΛΕΣ ΤΕΧΝΙΚΕΣ ΣΑΡΩΣΗΣ, ΔΙΑΤΥΠΩΝΟΝΤΑΙ ΜΕΡΙΚΕΣ ΕΝΔΙΑΦΕΡΟΥΣΕΣ ΙΔΙΟΤΗΤΕΣ ΤΩΝΠΑΡΑΓΟΜΕΝΩΝ SCAN ΠΡΟΤΥΠΩΝ. (ΠΕΡΙΚΟΠΗ)"],"dc:identifier":["10.12681/eadd/1188","http://hdl.handle.net/10442/hedi/1188"],"dc:language":["gre"],"dc:publisher":["Πανεπιστήμιο Πατρών","University of Patras"],"dc:subject":["CONTEXT-FREE LANGUAGES","GENERATION (OR IMPLEMENTATION) OF TREE-PYRAMIDS","HIERARCHICAL IMAGEDATA STRUCTURES","IMAGE SCANNING TECHNIQUES","Parallel implementation","PICTURE PROCESSING","R-D DATA ENCRYPTION","RECURSIVE ACCESSING TECHNIQUES","TEXTURE PATTERN GENERATION","ΑΝΑΔΡΟΜΙΚΕΣ ΤΕΧΝΙΚΕΣ ΠΡΟΣΠΕΛΑΣΗΣ ΔΕΔΟΜΕΝΩΝ","ΓΛΩΣΣΕΣ ΑΝΕΞΑΡΤΗΤΕΣ ΠΕΡΙΕΧΟΜΕΝΟΥ","ΔΗΜΙΟΥΡΓΙΑ TEXTURE ΕΙΚΟΝΑΣ","ΔΗΜΙΟΥΡΓΙΑ ΔΕΝΔΡΙΚΩΝ ΠΥΡΑΜΙΔΩΝ ΕΙΚΟΝΑΣ","Επεξεργασία εικόνας","ΙΕΡΑΡΧΙΚΕΣ ΔΟΜΕΣ ΔΕΔΟΜΕΝΩΝ ΕΙΚΟΝΑΣ","ΚΡΥΠΤΟΓΡΑΦΗΣΗ ΔΙΔΙΑΣΤΑΤΩΝ ΔΕΔΟΜΕΝΩΝ","ΠΑΡΑΛΛΗΛΗ ΥΛΟΠΟΙΗΣΗ","ΤΕΧΝΙΚΕΣ ΣΑΡΩΣΗΣ ΕΙΚΟΝΑΣ","Natural Sciences","Computer and Information Sciences","Engineering and Technology","Electrical Engineering, Electronic Engineering, Information Engineering","Φυσικές Επιστήμες","Επιστήμη Ηλεκτρονικών Υπολογιστών και Πληροφορική","Επιστήμες Μηχανικού και Τεχνολογία","Επιστήμη Ηλεκτρολόγου Μηχανικού, Ηλεκτρονικού Μηχανικού, Μηχανικού Η/Υ"],"dc:title":["SCAN: ΜΙΑ ΓΛΩΣΣΑ ΓΙΑ ΑΚΟΛΟΥΘΙΑΚΗ ΠΡΟΣΠΕΛΑΣΗ ΔΙΔΙΑΣΤΑΤΩΝ ΔΕΔΟΜΕΝΩΝ","SCAN: A LANGUAGE FOR TWO DIMENSIONAL DATA ACCESSING"],"dc:type":["PhD Thesis"]},"updated_at":"2026-07-24T02:24:46Z"}