Communication apparatus having coding/decoding means responsive to a settable coefficient

• US 5,889,549 A
• Filed: 09/27/1994
• Issued: 03/30/1999
• Est. Priority Date: 02/08/1991
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Chida, Makoto, Yasuda, Hitoshi
• Primary Examiner(s): WOO, STELLA L
• Application Number:
  US08/313,403
• Time in Patent Office: 1,645 Days
• Field of Search: 348/14, 348/15, 348/16, 348/17, 348/18, 348/19, 379/96, 379/102, 379/104, 379/105, 379/94, 379/93, 379/93.17, 379/93.21, 379/93.23, 379/102.02, 379/102.07
• US Class Current: 348/14.01
• CPC Class Codes: H04N 19/00 Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
• CPC Class Codes: H04N 19/154 Measured or subjectively estimated visual quality after decoding, e.g. measurement of distortion use of rate-distortion criteria H04N19/147
• CPC Class Codes: H04N 19/60 using transform coding
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 19/82 involving filtering within a prediction loop
• CPC Class Codes: H04N 7/148 Interfacing a video terminal to a particular transmission medium, e.g. ISDN
• CPC Class Codes: H04N 7/24 Systems for the transmission of television signals using pulse code modulation H04N21/00 takes precedence

Abstract

Disclosed is a communication apparatus in which coding and/or decoding parameters for coding and/or decoding data can be performed in dialog fashion to make possible the optimum coding of transmitted data and the optimum reproduction of received data. The apparatus includes a coefficient adjusting unit for adjusting coding and/or decoding parameters, and a decode-signal changeover unit for selecting, as an input signal to be decoded, one of a reception signal that has been received through a line and a transmission signal that has been coded, wherein the parameters are adjusted based upon the coded transmission signal. The apparatus further includes an image synthesizing unit for simultaneously displaying an input signal from input means and a decoded signal.

Claims

1. A communication apparatus comprising:

coding/decoding means for encoding original image data to be transmitted in accordance with a settable coefficient, and for decoding the encoded image data to provide decoded image data, said settable coefficient operative to adjust image quality;

output means for outputting an original image represented by the original image data and a decoded image represented by the decoded image data in respectively different output forms;

first setting means for manually setting a new settable coefficient, wherein said new settable coefficient directly affects image quality of the decoded image output by said output means by affecting encoding by said coding/decoding means; and

second setting means for automatically setting the coefficient for encoding and decoding.

2. A communication apparatus according to claim 1, wherein said coefficient is a quantizing coefficient.

3. A communication apparatus according to claim 1, wherein said coefficient is a size of filter used in a filtering process or a filtering coefficient.

4. A communication apparatus according to claim 1, wherein said original image includes a moving image.

5. A communication apparatus according to claim 1, further comprising audio communicating means for communicating audio data.

6. A method for adjusting image quality of a communications apparatus, comprising the steps of:

encoding original image data to be transmitted in accordance with a settable coefficient, and decoding the encoded image data to provide decoded image data, said settable coefficient operative to adjust image quality;

outputting an original image represented by the original image data and a decoded image represented by the decoded image data in respectively different output forms;

manually setting a new settable coefficient, wherein said new settable coefficient directly affects image quality of the decoded image output in said output step by affecting encoding by said coding/decoding step, and

automatically setting the coefficient for encoding and decoding.

7. A method according to claim 6, wherein said coefficient is a quantizing coefficient.

8. A method according to claim 6, wherein said coefficient is a size of filter used in a filtering process or a filtering coefficient.

9. A method according to claim 6, wherein said original image includes a moving image.

10. A method according to claim 6, further comprising a step of communicating audio data.

11. A communication apparatus comprising:

input means for inputting first image data;

receiving means for receiving second image data from an external apparatus;

coding/decoding means for encoding the first image data to be transmitted in accordance with a settable coefficient, and for decoding the encoded first image data to provide decoded first image data, said settable coefficient operative to adjust image quality;

output means for outputting a second image represented by the second image data and a first image represented by the decoded first image data; and

manually setting means for setting a new settable coefficient, wherein said new settable coefficient directly affects image quality of the first image output to the monitor by affecting coding by said coding/decoding means, said setting means being operational while said receiving means is receiving the second image data, and

automatic setting means for automatically setting the coefficient for encoding and decoding.

12. A communication apparatus comprising:

input means for inputting original image data;

coding/decoding means for encoding the original image data to be transmitted in accordance with a settable coefficient, and for decoding the encoded image data to provide decoded moving image data, said settable coefficient operative to adjust image quality;

output means for outputting an original image represented by the original image data and a decoded image represented by the decoded image data in respectively different output forms; and

setting means for manually and automatically setting the coefficient for encoding and decoding.

13. A communication apparatus according to claim 12, wherein said coefficient is a quantizing coefficient.

14. A communication apparatus according to claim 12, wherein said coefficient is a size of filter used in a filtering process or a filtering coefficient.

15. A communication apparatus according to claim 12, wherein said original image includes a moving image.

16. A communication apparatus according to claim 12, further comprising audio communicating means for communicating audio data.

17. A method for adjusting image quality of a communication apparatus, comprising the steps of:

inputting original image data;

encoding the original image data to be transmitted in accordance with a settable coefficient, and decoding the encoded image data to provide decoded moving image data, said settable coefficient operative to adjust image quality;

outputting an original image represented by the original image data and a decoded image represented by the decoded image data in respectively different output forms; and

manually and automatically setting the coefficient for encoding and decoding.

18. A method according to claim 17, wherein said coefficient is a quantizing coefficient.

19. A method according to claim 17, wherein said coefficient is a size of filter used in a filtering process or a filtering coefficient.

20. A method according to claim 17, wherein said original image includes a moving image.

21. A method according to claim 17, further comprising a step of communicating audio data.

22. A communication apparatus for communicating with a remote terminal, said communication apparatus comprising:

encoding means for encoding moving image information to provide encoded image information to be transmitted to the remote terminal and for decoding received moving image information received from the remote terminal;

decoding means for decoding the encoded moving image data provided by said encoding means to provide decoded moving image information and for outputting the decoded moving image information provided by said decoding means to a display;

means for generating encoding parameters for said encoding means; and

means for adjusting said encoding parameters so as to change a quality of the encoded moving image information while the decoded moving information is being output to the display, wherein said adjustment means is operable to adjust said encoding parameters during transmission of the encoded moving image information to the remote terminal.

23. A method operative in communication apparatus for communicating with a remote terminal, said method comprising the steps of:

encoding moving image information to provide encoded image information to be transmitted to the remote terminal, the communication apparatus being operative to decode received moving image information received from the remote terminal;

decoding the encoded moving image data provided at said encoding step to provide decoded moving image information;

outputting the decoded moving image information provided at said decoding step to a display;

generating encoding parameters for said encoding step; and

adjusting said encoding parameters so as to change a quality of the encoded moving image information while the decoded moving information is being output to the display, wherein said adjustment step is operable to adjust said encoding parameters during transmission of the encoded moving image information to the remote terminal.