Title:
【発明の名称】画像圧縮装置
Document Type and Number:
Japanese Patent JP2593453
Kind Code:
B2
Abstract:
PURPOSE:To improve a compression ratio without deteriorating picture quality by providing a 1st compression means irreversibly compressing an original image, an expansion means expanding a compressed image, a difference means taking the difference between an expanded image and its original and a 2nd compression means compressing the output. CONSTITUTION:The 1st compression means 2 irreversibly compresses the original image, and the expansion means 3 expands the compressed image. The difference means 4 takes the difference between the expanded image and its original, and the 2nd compression means 5 compresses the difference output. When the original image is irreversibly compressed and the compressed image is expanded, it has been deteriorated. In order to avoid the deterioration, the difference between the expanded image and its original is taken and compressed. With the aid of the difference compressed data, and image without deterioration can be restored because of the image that the 1st compression means 2 compresses. Besides to that, the volume of data can be considerably reduced because an irreversible compression method is adopted for the 1st compression means 2.
Inventors:
Eitaro Nishihara
Application Number:
JP18917486A
Publication Date:
March 26, 1997
Filing Date:
August 12, 1986
Export Citation:
Assignee:
Toshiba Corporation
International Classes:
A61B6/00; G06T9/00; H04N1/411; H04N1/417; (IPC1-7): G06T9/00; A61B6/00
Domestic Patent References:
| JP61149126A | ||||
| JP679334B2 |
Attorney, Agent or Firm:
Hideaki Tokawa (1 outside)