Monodimensional cosine transform calculators and image coding and decoding devices using such calculators

Abstract

Abstract The invention relates in particular to a device for calculating 16 one-dimensional direct cosine transformations from 16 values representing, for example, the brightness of 16 picture points. It comprises: - an input memory (3); - first calculating means (6) furnishing respectively two values of the form A + B and (A - B) x D, where A and B are two values applied respectively to two inputs of these calculating means (6) and where D is a predetermined coefficient; - first means (4) of storing intermediate values, allowing the first calculating means (16) to be employed again for 32 similar operations; - second calculating means (7) furnishing a value of the form E + G, where E and G are two values applied consecutively to the input of these second calculating means (7); - second means (8) of storing intermediate values, allowing the second calculating means (7) to be used again for 17 addition operations; - a device (9) for changing the order of the transformed values. <??>Application to devices for encoding and decoding television pictures by two-dimensional direct cosine transformation with a view to reducing the quantity of data. <IMAGE>

Inventors

• 👤 Jean-Yves Aubie
• 👤 Yves-Marie Le Pannerer
• 👤 Alain Ferre
• 👤 Yannick Villalon

Bibliographic Details