Reconstructing a compressed still image by transformation to a compressed moving picture image

• US 7,379,498 B2
• Filed: 03/11/2002
• Issued: 05/27/2008
• Est. Priority Date: 03/11/2002
• Status: Expired due to Fees

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Silyaev, Vladimir, Fisher, Jeff, Kellerman, Marcus, Chen, Sherman (Xuemin), Fu, Jiang, Rajakarunanayake, Yasantha
• Primary Examiner(s): DIEP, NHON THANH
• Application Number:
  US10/095,258
• Publication Number:
  US 20030169814A1
• Time in Patent Office: 2,269 Days
• Field of Search: 37524012-24016, 375/240.18, 375/240.2, 375/240.24, 382/232, 382/236, 386/111, 709/204, 348/232, 455/435
• US Class Current: 375/240.12
• CPC Class Codes: H04N 19/124 Quantisation
• CPC Class Codes: H04N 19/186 the unit being a colour or a chrominance component
• CPC Class Codes: H04N 19/40 using video transcoding, i.e. partial or full decoding of a coded input stream followed by re-encoding of the decoded output stream
• CPC Class Codes: H04N 19/60 using transform coding
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 19/70 characterised by syntax aspects related to video coding, e.g. related to compression standards
• CPC Class Codes: H04N 19/90 using coding techniques not provided for in groups H04N19/10-H04N19/85, e.g. fractals

Abstract

A transcoder (10) and a decoder (80) reconstruct an image from still image compressed data, such as EXIF data. The transcoder transcodes the still image compressed data into a bit stream of moving picture compressed data, such as an MPEG-2 4:2:2P bit stream with only intra pictures. The decoder (80) decodes the bit stream of moving picture compressed data into a still picture image that can be stored in a digital memory (100).

Claims

1. Apparatus for reconstructing an image from still image compressed data, comprising:

a transcoder arranged to transcode the still image compressed data into a bit stream of moving picture compressed data, the bit stream of moving picture compressed data comprising MPEG data and comprising I pictures, the bit stream of moving picture compressed data not comprising P pictures and B pictures, the transcoder comprising a Huffman encoder, a prediction and quantizer module, a still image compressed data decoder and a stream construction module, the stream construction module being downstream of the Huffman encoder and multiplexing Huffman code with MPEG table values, the Huffman encoder being downstream of the prediction and quantizer module, the prediction and quantizer module being downstream of the still image compressed data decoder, the transcoder transcoding without performing a discrete cosine transform; and

a second decoder arranged to generate the reconstructed image by decoding the bit stream of moving picture compressed data,

wherein the still image compressed data comprises discrete cosine transformed data and wherein the second decoder is arranged to perform an inverse discrete cosine transform, and

wherein the still image compressed data comprises EXIF data and wherein the bit stream of moving picture compressed data does not include MPEG-1 data.

2. The apparatus of claim 1 wherein the EXIF data comprises JPEG data.

3. The apparatus of claim 2 wherein the MPEG-2 data comprises a luminance component, a first chrominance component and a second chrominance component.

4. The apparatus of claim 3 wherein the luminance component is represented by 4 bits, the first chrominance component is represented by two bits and the second chrominance component is represented by two bits.

5. The apparatus of claim 2 wherein the EXIF data comprises a header and wherein the transcoder comprises:

a parser of the header arranged to generate parsed header data;

a JPEG decoder arranged to generate decoded data in response to the parsed header data and to map the decoded data into MPEG-2 syntax elements;

a DC predictor and quantizer arranged to generate MPEG-2 quantization data in response to the MPEG-2 syntax elements;

a Huffman encoder arranged to generate encoded data in response to the quantization data; and

a stream construction device responsive to the encoded data and the MPEG-2 syntax elements to generate MPEG-2 compressed data.

6. The apparatus of claim 5 wherein the JPEG decoder is responsive to a specification table.

7. The apparatus of claim 6 wherein the specification table comprises luminance quantization data, chrominance quantization data and Huffman code data.

8. The apparatus according to claim 1,

wherein the transcoder comprises a table specification memory,

wherein the table specification memory is operatively coupled to each of the following:

the Huffman encoder, the prediction and quantizer module, the still image compressed data decoder and the stream construction module,

wherein the stream construction module does not provide an MPEG-1 bit stream, and

wherein the stream construction module provides a 4;

2;

2 bit stream.

9. A method of reconstructing an image from still image compressed data comprising:

transcoding the still image compressed data into a bit stream of moving picture compressed data, the bit stream of moving picture compressed data comprising MPEG data and comprising I pictures, the bit stream of moving picture compressed data not comprising P pictures and B pictures; and

generating the reconstructed image by decoding the bit stream of moving picture compressed data,

wherein the still image compressed data comprising still image luminance data, chrominance data, block data, variable length coding data, vertical line data, horizontal line data and DC coefficient data,

wherein the transcoding comprises

parsing the still image compressed data;

extracting a Huffman table and a quantization matrix from the parsed still image compressed data;

mapping the extracted Huffman table and the extracted quantization matrix into syntax elements that are not MPEG-1 syntax elements;

converting the still image luminance data to moving picture compatible luminance data,

converting the still image chrominance data to moving picture compatible chrominance data,

converting the still image block data to moving picture compatible block data,

converting the still image variable length coding data to moving picture compatible variable length coding data,

converting the still image vertical line data to moving picture compatible vertical line data,

converting the still image horizontal line data to moving picture compatible horizontal line data, and

converting the still image DC coefficient data to moving picture compatible DC coefficient data,

wherein the decoding comprises decoding the moving picture compatible luminance data, chrominance data, block data, variable length coding data, vertical line data, horizontal line data and DC coefficient data to form an image,

wherein the still image compressed data further comprises discrete cosine transformed data and wherein the decoding comprises performing an inverse discrete cosine transform,

wherein the still image compressed data comprises EXIF data, and

wherein the moving picture compatible luminance data, chrominance data, block data, variable length coding data, vertical line data, horizontal line data and DC coefficient data does not comprise MPEG-1 data.

10. The method of claim 9 wherein the still image block data comprises 8 by 8 block data and wherein the moving picture compatible block data comprises 16 by 16 block data.

11. The method of claim 9 wherein the variable length coding data comprises Huffman coding data.

12. The method of claim 9 wherein the DC coefficient data comprises DC coefficients of intra coded block data.

13. The method of claim 9 wherein the EXIF data comprises JPEG data.

14. The method of claim 9 wherein the still image compressed chrominance data comprises a first chrominance component and a second chrominance component.

15. The method of claim 14 wherein the still image luminance data is represented by 4 bits, the first chrominance component is represented by two bits and the second chrominance component is represented by two bits.

16. An application specific integrated circuit (ASIC) that reconstructs an image from still image compressed data, comprising:

a transcoder arranged to transcode the still image compressed data into a bit stream of moving picture compressed data, the bit stream of moving picture compressed data not comprising MPEG-1 data, the bit stream of moving picture compressed data comprising I pictures, the bit stream of moving picture compressed data not comprising P pictures and B pictures; and

a decoder arranged to generate the reconstructed image by decoding the bit stream of moving picture compressed data,

wherein the still image compressed data comprises discrete cosine transformed data and wherein the decoder is arranged to perform an inverse discrete cosine transform,

wherein the still image compressed data comprises EXIF data,

wherein the transcoder comprises a variable length Huffman encoder, a DC prediction and quantizer module, a still image compressed data decoder and a stream construction module,

wherein the stream construction module is downstream of the Huffman encoder and multiplexes Huffman code with MPEG table values,

wherein the Huffman encoder is downstream of the DC prediction and quantizer module, and

wherein the DC prediction and quantizer module is downstream of the still image compressed data decoder.

17. The ASIC according to claim 16, wherein the transcoder is arranged to transcode without performing a discrete cosine transform.

18. The ASIC according to claim 16, wherein the transcoder requantizes a Cr component if different quantization matrices are used for Cb and Cr.

19. The ASIC according to claim 16, wherein the ASIC is used in a digital set-top box that processes compressed moving pictures.

20. The ASIC according to claim 16, wherein the transcoder only requantizes a Cr component if different quantization matrices are used for Cb and Cr.