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Rd optimized progressive image coding using JPEG In, Jaehan
Abstract
The JPEG standard allows four modes of operation. They are the hierarchical (HJPEG), progressive (PJPEG), sequential (SJPEG), and lossless modes1: The HJPEG and PJPEG modes inherently support progressive image coding. In HJPEG, an image is decomposed into subimages of different resolution, each of which is then coded using one of the other three modes of JPEG. Progressiveness within a resolution in HJPEG can be achieved when each subimage is coded using PJPEG. An image coded using PJPEG consists of scans, each of which contributes to a portion of the reconstructed image quality. While SJPEG yields essentially the same level of compression performance for most encoder implementations, the performance of PJPEG depends highly upon the designed encoder structure. This is due to the flexibility the standard leaves open in designing PJPEG encoders. In this thesis, an efficient progressive image, coding algorithm is developed that is compliant with the JPEG still image compression standard. The JPEG-compliant progressive image encoder is a HJPEG encoder that employs a rate-distortion optimized PJPEG encoding algorithm for each image resolution. Our encoder outperforms an op- timized SJPEG encoder in terms of compression efficiency, substantially at low and high bit rates. Moreover, unlike existing J P EG compliant encoders, our encoder can achieve precise rate control for each fixed resolution. Such good compression performance at low bit rates and precise rate control are two highly desired features currently sought for the emerging JPEG-2000 standard. 1 Lossless JPEG algorithms are rarely used since their performance levels are significantly lower than those of other lossless image compression algorithms, and are therefore not widely used.
Item Metadata
Title |
Rd optimized progressive image coding using JPEG
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Creator | |
Publisher |
University of British Columbia
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Date Issued |
1998
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Description |
The JPEG standard allows four modes of operation. They are the hierarchical (HJPEG),
progressive (PJPEG), sequential (SJPEG), and lossless modes1: The HJPEG and PJPEG
modes inherently support progressive image coding. In HJPEG, an image is decomposed
into subimages of different resolution, each of which is then coded using one of the other
three modes of JPEG. Progressiveness within a resolution in HJPEG can be achieved
when each subimage is coded using PJPEG. An image coded using PJPEG consists of
scans, each of which contributes to a portion of the reconstructed image quality. While
SJPEG yields essentially the same level of compression performance for most encoder
implementations, the performance of PJPEG depends highly upon the designed encoder
structure. This is due to the flexibility the standard leaves open in designing PJPEG
encoders.
In this thesis, an efficient progressive image, coding algorithm is developed that is
compliant with the JPEG still image compression standard. The JPEG-compliant progressive
image encoder is a HJPEG encoder that employs a rate-distortion optimized
PJPEG encoding algorithm for each image resolution. Our encoder outperforms an op-
timized SJPEG encoder in terms of compression efficiency, substantially at low and high
bit rates. Moreover, unlike existing J P EG compliant encoders, our encoder can achieve
precise rate control for each fixed resolution. Such good compression performance at low
bit rates and precise rate control are two highly desired features currently sought for the
emerging JPEG-2000 standard.
1 Lossless JPEG algorithms are rarely used since their performance levels are significantly lower than
those of other lossless image compression algorithms, and are therefore not widely used.
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Extent |
6640636 bytes
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Genre | |
Type | |
File Format |
application/pdf
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Language |
eng
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Date Available |
2009-05-19
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Provider |
Vancouver : University of British Columbia Library
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Rights |
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
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DOI |
10.14288/1.0064806
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URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
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Graduation Date |
1998-05
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Campus | |
Scholarly Level |
Graduate
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Aggregated Source Repository |
DSpace
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Item Media
Item Citations and Data
Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.