Apparatus for block-encoding input image signals

• US 6,243,139 B1
• Filed: 06/27/1997
• Issued: 06/05/2001
• Est. Priority Date: 12/22/1993
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Kashida, Motokazu, Takahashi, Koji
• Primary Examiner(s): Sniezek, Andrew L.
• Application Number:
  US08/884,621
• Time in Patent Office: 1,439 Days
• Field of Search: 360/9.1, 360/27, 360/33.1, 360/32, 360/67, 360/31, 360/53, 360/22, 358/335, 358/339, 369/53, 369/54, 348/420, 348/384, 348/390, 348/400, 348/401, 348/402, 348/403, 348/409-413, 386/109, 386/111, 386/112, 386/93, 386/9, 386/33, 382/232, 382/236, 382/238, 382/248-251
• US Class Current: 348/420.1
• CPC Class Codes: G11B 2220/90 Tape-like record carriers
• CPC Class Codes: G11B 27/031 Electronic editing of digitised analogue information signals, e.g. audio or video signals
• CPC Class Codes: H04N 19/112 according to a given display mode, e.g. for interlaced or progressive display mode
• CPC Class Codes: H04N 9/7921 for more than one processing mode
• CPC Class Codes: H04N 9/8047 using transform coding
• CPC Class Codes: H04N 9/8205 involving the multiplexing of an additional signal and the colour video signal

Abstract

There is provided an apparatus capable of preventing the image quality deterioration, in the block encoding of an image signal which has already been subjected to encoding, such as in the dubbing operation, by entering block forming information relating to the block forming operation applied previously to the image signal, at the entry of the image signal, and dividing the image signal into blocks according to the block forming information.

Claims

1. An image processing apparatus, comprising:

receiving means for receiving an image signal which has been (i) blocked-encoded by dividing it into a plurality of blocks and then (ii) block-decoded from the plurality of encoded blocks, and for receiving mode information used in the block-encoding processing performed on the received image signal from outside of said image processing apparatus, and for outputting the received image signal and the received mode information, said receiving means outputting the received mode information without using the received image signal; and

block encoding means for block-encoding said received image signal output from said receiving means by using the received mode information output from said receiving means.

2. An apparatus according to claim 1, further comprising:

generation means for generating mode information, utilizing said received image signal;

wherein said block encoding means is capable of effecting the block encoding process according to the mode information from said generation means.

3. An apparatus according to claim 2, further comprising:

control means for supplying one of said received mode information output from said receiving means and the mode information from said generation means to said block encoding means.

4. An apparatus according to claim 3, further comprising:

encoding means for compressing the amount of information of the image signal from said block encoding means and encoding the image signal; and

wherein said encoding means encodes according to the output from said control means.

5. An apparatus according to claim 4, further comprising:

record/reproduction means for recording the image signal from said encoding means and the mode information from said control means, and for reproducing the recorded image signal and the recorded mode information.

6. An apparatus according to claim 5, further comprising:

decoding means for expanding the amount of information of the image signal reproduced by said record/reproduction means, and for decoding the reproduced image signal;

1st output means for outputting the image signal from said decoding means; and

2nd output means for outputting, to an outside of said apparatus, the mode information reproduced by said record/reproduction means.

7. An apparatus according to claim 3, wherein said control means is adapted to effect said supplying operation according to the kind of said received image signal output from said receiving means.

8. An apparatus according to claim 2, wherein said generation means includes correlation detection means for detecting a correlation between mutually different images in said received image signal.

9. An apparatus according to claim 2, wherein said generation means includes estimation means for estimating the mode of block encoding processing applied to said received image signal before said received image signal is output from said receiving means.

10. An apparatus according to claim 1, wherein said received image signal includes a frame consisting of plural fields, and wherein said block encoding means is adapted to selectively form a frame block consisting of the pixels of said plural fields or a field block consisting solely of the pixels of a predetermined field within said plural fields, according to said received mode information.

11. An image processing apparatus, comprising:

a) level control means for controlling the level of an input digital image signal;

b) compression means for compressing the amount of information of the digital image signal from said level control means by a block-encoding method;

c) expansion means for expanding the amount of information of the digital image signal compressed by said compression means by a block-decoding method corresponding to the block-encoding method;

d) detection means for detecting the deterioration in image quality of said input digital image signal due to the compression process and the expansion process by performing the compression process by the block-encoding method and expansion process by the block-decoding process, in succession; and

e) control means for controlling said level control means according to the output of said detection means.

12. An apparatus according to claim 11, wherein said detection means includes comparison means for comparing the image quality of the image signal from said expansion means and that of said input digital image signal, and is adapted to detect said deterioration in image quality, based on the output of said comparison means.

13. An apparatus according to claim 12, wherein said compression means is capable also of compressing the image signal from said expansion means, and wherein said comparison means is adapted to compare (i) the image signal from said expansion means, obtained by applying compression and expansion plural times on said input digital image signal, and (ii) said input digital image signal.

14. An apparatus according to claim 11, wherein said control means is adapted to control said detection means so as to vary the method of detection before said deterioration in image quality, according to the compression rate in said compression means.

15. An apparatus according to claim 11, further comprising:

record/reproduction means for recording the image signal from said compression means and reproducing the recorded signal;

wherein said expansion means is adapted also to expand the amount of information of the image signal reproduced by said record/reproduction means.

16. An image processing apparatus, comprising:

level control means for controlling the level of an input image signal, said input image signal being an image signal that has been blocked-formed by dividing it into a plurality of blocks and then reconstructed from the plurality of blocks;

information input means for inputting mode information associated with said input image signal, said mode information indicating a mode of block-forming processing performed on the image signal before the image signal is input to said apparatus;

block forming means for dividing the input image signal into a plurality of blocks, each block comprising a plurality of pixels, according to the mode information input by said information input means;

information input means for entering block formation information relating to said block forming process applied previously on said input image signal;

wherein said block forming means is adapted to effect said block forming process according to the block formation information from said information input means;

compression means for compressing an amount of information of the image signal from said block forming means;

expansion means for expanding the amount of information of the image signal from said compression means;

wherein said compression means and said expansion means vary said compression process and said expansion process respectively, according to the mode information;

detection means for detecting a deterioration in image quality of said input image signal by performing said compression and expansion processes on said input image signal in succession; and

control means for controlling said level control means according to the output of said detection means.

17. An apparatus according to claim 16, further comprising:

generation means for generating the mode information, utilizing said image signal; and

wherein said block forming means is capable of effecting said block forming process, according to the mode information from said generation means.

18. An apparatus according to claim 16, wherein said detection means includes comparison means for comparing (i) the image quality of the image signal from said expansion means and (ii) said input image signal, and wherein said detection means is adapted to detect said deterioration in image quality based on the output of said comparison means.

19. A reproducing apparatus, comprising:

reproduction means for reproducing (i) an image signal divided into a plurality of blocks each of which comprises a plurality of pixels encoded in the block unit, and (ii) mode information recorded after a dividing process performed to form said plurality of blocks, from a recording medium;

decoding means for decoding said plurality of encoded blocks of the image signal reproduced by said reproducing means, by using the mode information reproduced by said reproducing means; and

output means for outputting the mode information to an outside of said reproducing apparatus together with the image signal decoded by said decoding means so that the mode information output from said output means can be used to divide the decoded image signal output together with the mode information, into a plurality of blocks again.

20. An apparatus according to claim 19, further comprising:

inverse block forming means for arranging said image signal in a predetermined sequence of pixels, according to the mode information from said reproduction means.

21. An apparatus according to claim 19, wherein said image signal is recorded, with a compression in the amount of information, on said recording medium.

22. An apparatus according to claim 21, further comprising:

expansion means for expanding the amount of information of the image signal from said reproduction means;

wherein said expansion means is adapted to vary the expansion process according to said mode information.

23. An apparatus according to claim 22, wherein said expansion means is adapted to vary the sequence of pixels to be subjected to said expansion process, according to said mode information.

24. An apparatus according to claim 22, further comprising:

image output means for outputting the image signal from said expansion means to an outside of said apparatus.

25. An image processing apparatus, comprising:

receiving means for receiving an image signal, and for outputting the received image signal to encoding means, said receiving means receiving a decoded image signal as the received image signal; and

mode information supplying means for acquiring encoding mode information associated with the image signal received by said receiving means, and for supplying the acquired encoded mode information to a recording means, said supplying means acquiring the encoding mode information without using the image signal received by said receiving means, said encoding means encoding the decoded image signal output from said receiving means, by using the encoding mode information supplied from said mode information supplying means.

26. Apparatus according to claim 25, wherein said encoding means includes means for dividing the received image signal into a plurality of blocks each comprising a plurality of pixels, and for performing an encoding processing on a block basis.

27. Apparatus according to claim 25, wherein said encoding means further compresses amount information of the received image signal.

28. Apparatus according to claim 25, further comprising recording means for recording on a recording medium the image signal encoded by said encoding means.