Image data compressing device for endoscope

• US 4,845,553 A
• Filed: 05/19/1988
• Issued: 07/04/1989
• Est. Priority Date: 05/22/1987
• Status: Expired due to Term

• Current Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Original Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Inventors: Tsuruoka, Takao, Konomura, Yutaka
• Primary Examiner(s): Groody, James J.
• Assistant Examiner(s): Kostak, Victor R.
• Application Number:
  US07/195,937
• Time in Patent Office: 411 Days
• Field of Search: 358/98, 358/138, 358/133, 358/12, 358/13, 358/44, 358/15
• US Class Current: 348/71
• CPC Class Codes: G06T 9/005 Statistical coding, e.g. Huffman, run length coding
• CPC Class Codes: H04N 23/555 for picking-up images in sites, inaccessible due to their dimensions or hazardous conditions, e.g. endoscopes or borescopes
• CPC Class Codes: H04N 23/84 for processing colour signals
• CPC Class Codes: H04N 25/11 Arrangement of colour filter arrays [CFA]; Filter mosaics

Abstract

Disclosed is an image data compressing device for an endoscope which is for use in converting a plurality of color signals obtained by separating the image provided by the endoscope into electrical signals and then quantizing and storing the thus-obtained signals. The image data compressing device includes sampling means for conducting sampling at sampling intervals which are different for each of the plurality of color signals and which correspond to the characteristics of each of the plurality of colors in the image obtained by the endoscope, so as to enable the image data to be compressed in accordance with the characteristics of each of the colors of the image provided by the endoscope.

In consequence, data compression can be conducted without losing the quality of the image provided by the endoscope.

Claims

1. An image data compressing device for an endoscope which is for use in converting a plurality of color signals obtained by separating the image provided by said endoscope into electrical signals and then quantizing and storing said signals, said image data compressing device being characterized by an inclusion of sampling means for conducting sampling at sampling intervals which are different for each of said plurality of color signals and which corresponds to the characteristics of each of said plurality of colors in the image obtained by said endoscope, such that image data are compressed in accordance with the characteristics of each of said colors in the image provided by said endoscope.

2. An image data compressing device for an endoscope according to claim 1, wherein said characteristics of each of said colors in said image provided by said endoscope are set on the basis of the spatial frequency distribution thereof.

3. An image data compressing device for an endoscope according to claim 1, wherein said color signals representing the image provided by said endoscope comprise three primary color signals of red, green and blue, and the sampling intervals for said R signal is large while those for said G and B signals are respectively small and a median value between those for said R and G signals.

4. An image data compressing device for an endoscope according to claim 3, wherein the sampling intervals for each of said color signals representing the image provided by said endoscope are made different in the horizontal and/or vertical direction.

5. An image data compressing device for an endoscope according to claim 3, wherein the pixel data of the R signal representing the image provided by said endoscope are sampled once every three dots by the sampling clocks that are passed through a one-third circuit, the pixel data of the G signal are sampled for each dot, and the pixel data of the B signal is sampled for every other dot by the sampling clocks that are passed through a one-half circuit.