ΑΝΑΠΤΥΞΗ ΑΠΟΔΟΤΙΚΩΝ ΑΛΓΟΡΙΘΜΩΝ DCT, DST, ΔΙΑΝΥΣΜΑΤΙΚΗΣ ΚΒΑΝΤΙΣΗΣ ΠΛΕΓΜΑΤΟΣ ΚΑΙ ΑΡΧΙΤΕΚΤΟΝΙΚΩΝ VLSI ΓΙΑ ΣΥΜΠΙΕΣΗ ΕΙΚΟΝΩΝ ; DEVELOPMENT OF EFFICIENT DCT, DST, LATTICE VECTOR QUANTIXATION ALGORITHMS, AND VLSI ARCHITECTURES FOR IMAGE COMPRESSION

IN THIS DISSERTATION EFFICIENT ALGORITHMS AND VLSI ARCHITECTURES FOR LOSSY COMPRESSION OF STILL IMAGES ARE DEVELOPED. ALGORITHMS ARE PRESENTED FOR COMPUTING THE 1-D AND 2-D DISCRETE COSINE TRANSFORM (DCT). THE ALGORITHMS ARE BASED ONPRIME-FACTOR DECOMPOSITION PROPERTIES AND CAN BE IMPLEMENTED ON SLIGHTLY-MODIFIED EXISTING VLSI ARCHITECTURES OF THE DFT. ALTERNATIVE ARCHITECTURES SUITABLE FOR VLSI IMPLEMENTATION OF THE 2-D DCT WITH VARYING THROUGHPUT AND HARDWARE COMPLEXITY ARE SYSTEMATICALLY DERIVED. THEY ARE BASED ON THE EXISTENCE OF A FEW CONNECTED COMPONENTS AT THE SIGNAL-FLOW GRAPH OF THE PROPOSED ALGORITHM. A VLSI ARCHITECTURE FOR THE COMPUTATION OF THE 2-D NXN-POINT DCT IS PRESENTED, WHERE N IS A POWER OF 2. THE PROPOSED BIT-SERIAL ARCHITECTURE HAS HIGHLY REGULAR STRUCTURE AND EXHIBITS HIGH DATA THROUGHOUT RATE. IT IS BASED ON A HIGH PERFORMANCE APPLICATION SPECIFIC MULTIPLIER AND IT IS MORE EFFICIENT THAN OTHERDCT ARCHITECTURES. A CHIP WAS DESIGNED FOR THE COMPUTATION OF THE 4X4-POINT DCT EXHIBITING A PERFORMANCE OF 246 MPIXELS/SEC, WHICH IS SUFFICIENT EVEN FORTHE PROCESSING OF HDTV SIGNALS. A COMPUTATIONALLY EFFICIENT AND HIGH PERFORMANCE LATTICE VECTOR QUANTIZER BASED ON RESIDUE NUMBER SYSTEM, IS PRESENTED. THERE IS NO NEED FOR CODEBOOK STORAGE AND THE CODEVECTORS ARE ALGORITHMICALLY GENERATED. THE PROPOSED ALGORITHM IS DEVELOPED FOR ARBITRARY VECTOR DIMENSIONAND HAS A VERY REGULAR AND PARALLEL STRUCTURE. THE PROPOSED ALGORITHM IS DEVELOPED FOR ARBITRARY VECTOR DIMENSION AND HAS A VERY REGULAR AND PARALLEL STRUCTURE. (ABSTRACT TRUNCATED) ; Η ΔΙΔΑΚΤΟΡΙΚΗ ΔΙΑΤΡΙΒΗ ΔΙΑΠΡΑΓΜΑΤΕΥΕΤΑΙ ΑΠΟΔΟΤΙΚΟΥΣ ΑΛΓΟΡΙΘΜΟΥΣ ΚΑΙ ΑΡΧΙΤΕΚΤΟΝΙΚΕΣ ΤΕΧΝΟΛΟΓΙΑΣ ΠΟΛΥ ΜΕΓΑΛΗΣ ΚΛΙΜΑΚΑΣ ΟΛΟΚΛΗΡΩΣΗΣ ΓΙΑ ΤΗ ΣΥΜΠΙΕΣΗ ΑΚΙΝΗΤΩΝ ΨΗΦΙΑΚΩΝ ΕΙΚΟΝΩΝ ΜΕ ΑΠΩΛΕΙΑ ΠΛΗΡΟΦΟΡΙΑΣ. ΠΡΟΤΕΙΝΟΝΤΑΙ ΑΛΓΟΡΙΘΜΟΙ ΓΙΑ ΤΟΝ ΥΠΟΛΟΓΙΣΜΟ ΤΟΥ 1-Δ ΚΑΙ 2-Δ DCT ΚΑΙ ΤΟΥ 1-Δ DST. ΟΙ ΑΛΓΟΡΙΘΜΟΙ ΧΡΗΣΙΜΟΠΟΙΟΥΝ ΤΗ ΜΕΘΟΔΟ ΑΝΑΛΥΣΗΣ ΣΕ ΠΡΩΤΟΥΣ ΠΑΡΑΓΟΝΤΕΣ. ΟΙ ΣΥΝΤΕΛΕΣΤΕΣ ΤΩΝ ΜΕΤΑΣΧΗΜΑΤΙΣΜΩΝ ΥΠΟΛΟΓΙΖΟΝΤΑΙ ΜΕΣΩ ΤΟΥ DFT ΚΑΙ ΤΩΝ ΚΑΤΑΛΛΗΛΩΝ ΒΑΘΜΙΔΩΝ ΕΠΕΞΕΡΓΑΣΙΑΣ. Η ...