Image signal processing apparatus

• US 20030095713A1
• Filed: 11/21/2002
• Published: 05/22/2003
• Est. Priority Date: 11/22/2001
• Status: Active Grant

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Tanaka, Satoshi, Yabumoto, Tetsuro, Sugimura, Yukio, Toguchi, Akira
• Granted Patent: US 7,203,370 B2
• Time in Patent Office: Days
• US Class Current: 382/239
• CPC Class Codes: G06T 9/007 Transform coding, e.g. discrete cosine transform

Abstract

An image signal processing apparatus includes two JPEG codecs. A plurality of frames of image signals periodically input from a multiplexer are individually compressed by the two JPEG codecs, and the compressed image signals are recorded on a hard disk by an HDD. Furthermore, the plurality of frames of the compressed image signals reproduced from the hard disk are individually expanded by the two JPEG codecs, and the expanded image signals are output to a monitor. Herein, each of the JPEG codecs selectively executes individual compression of the plurality of frames of the image signals and individual expansion of the plurality of frames of the compressed image signals. A CPU makes the JPEG codecs perform the compression process prior to the expansion process.

Claims

1. An image signal processing apparatus for recording onto a recording medium in a compressed state a plurality of screens of image signals periodically input at every first number of screens and periodically outputting a plurality of screens of compressed image signals reproduced from said recording medium in an expanded state at every second number of screens, comprising:

at least one codec for selectively executing a compression process for individually compressing the plurality of screens of image signals and an expansion process for individually expanding the plurality of screens of compressed image signals; and

a processor for making said codec perform the compression process prior to the expansion process.

2. An image signal processing apparatus according to claim 1, wherein processes executed by said processor includes a requesting process for repeatedly requesting said codec to perform the compression process on the same image signal until a size condition is satisfied.

3. An image signal processing apparatus according to claim 1, wherein said codec exists in plurality, and processes executed by the said processor includes a determination process for determining whether or not an input image signal satisfies a predetermined condition, an occupying process for occupying all of said codecs for the purpose of the compression process when the predetermined condition is satisfied and a release process for releasing at least one of said codecs for the purpose of the expansion process when the predetermined condition is not satisfied.

4. An image signal processing apparatus according to claim 3, further comprising a memory for temporarily storing the input image signal, wherein the predetermined condition includes a first condition that a plurality of screens of image signals are waiting for the compression process in said memory.

5. An image signal processing apparatus according to claim 3, wherein said predetermined condition includes a second condition that the image signals greatly change between screens.

6. A surveillance camera system provided with an image signal processing apparatus according to any one of claims 1 to 5.