| 摘要 |
PURPOSE:To reduce the capacity of an output vector code table down to about half for both a coder and a decoder by making use of the inverse relation of the output vector. CONSTITUTION:When the normalized output vector is set, those normalized output vectors set to each stage are arrayed so that they are symmetrical to each other centering on an original point in a signal space every half of the vectors between the right and the left of a tree. That is, the inverse relation is secured among those output vectors. An index register 18 fetches the output signal of a comparator and sets it to the highest bit position of an n-digit index in the form of the information showing the polarity of the normalized output vector. Then the index signal is delivered. A normalized input vector 103 is supplied to a selector 104 together with a normalized input vector 105 inverted by a polarity inverting circuit 102. Thus the capacity of an output vector code table can be reduced down to about half for a tree searching vector quantizer. |
