The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 25, 1989
Filed:
Feb. 26, 1988
Norio Suzuki, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
An adaptive quantizing device for use in a differential encoder which makes use of a device input signal variable in a predetermined dynamic range, a local decoded signal, and a local input signal from a prediction signal. The quantizing arrangement (12, 13) is provided for adaptively quantizing a difference between the device and the local input signals into a quantization output signal in accordance with a predetermined quantization characteristic so that the local decoded signal never exceeds the dynamic range even if the quantization output signal is accompanied by a quantization error of a maximum value. Preferably, the quantizing arrangement comprises a converting circuit (16) for quantizing the device input signal into a converted signal in accordance with a preselected quantization characteristic for use in making a single quantizer (13) adaptively quantize the difference into the quantization output signal. Alternatively, the quantizing arrangement may comprise three quantizers and a selecting arrangement for adaptively selecting one of outputs of the three quantizers. A read-only memory is preferred in implementing each of the single quantizer, the converting circuit, the three quantizers, and a combination of the three quantizers and the selecting arrangement.