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:
Dec. 10, 1996
Filed:
Nov. 30, 1994
Akira Satoh, Tokyo, JP;
NEC Corporation, , JP;
Abstract
An object of the invention is to provide an image scrambling apparatus and an image descrambling apparatus capable of making a communication of secrecy by scrambling a digital image signal as well as variable-length-encoding the digital image signal. A transmitting apparatus 1 DCT-encodes an image signal V2 from an A/D converter 11 by means of a DCT encoder 12, and outputs signals of D1, D2, D3, D4, and the number of zero-runs D5. When it variable-length-encodes the D2 to D5 through a variable-length encoder 13 and outputs V3, it generates a series of PN signals K2 by means of a PN generator 18 on the basis of a PN initial value K1 from a PN initial value generator 17, adds the scalar quantumizing number D1 and K2 to each other by means of an adder 19 and outputs the scrambled D1, and then gives a scrambled image signal V4 through compositing the V3 and the D1.