Recommended usage for JPEG 2000 (JP2) format is as an access version for image based files. The JPEG2000 format provides enhance online viewing of graphically dense images by allowing a user to zoom and view greater detail than a low resolution format. This format requires special software to create and view online. The IR has been configured to present these images through common web browsers and allows JP2 files to be downloaded directly or a snap shot of an online view may also be downloaded as simple jpeg.
Guidelines for creating JPEG2000 files
Significant characteristics
Parameters
Used for
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Image type: Maps, illustrations, photographs
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Conversion software used
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Kakadu
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Online display software
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djatoka
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File format
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Part 1 (.jp2)
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Lossy or lossless
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Lossy
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Typical compression
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Tiling
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1024x1024
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Progression order
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RPCL
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Number of decomp. Levels
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Number of quality layers
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Code black size (xcb=ycb)
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6
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Transformation
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Precinct size
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256x256 for first two decomp. levels,
128x128 for lower levels
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Regions of Interest
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No
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Code blck size
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64x64
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TLM markers
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Yes “R”
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Bypass
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Yes
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Command line code: ./kdu_compress -i example.jp2 "Cblk={64,64}" Corder=RPCL "Stiles={1024,1024}" "Cprecincts={256,256},{128,128}" ORGtparts=R -rate 1 Clayers=12 Clevels=5 "Cmodes={BYPASS}"
History
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Initially reviewed JPEG2000 as an "archival format" or replacement for TIFF files. Determine this use was not an acceptable preservation format. Reasons (briefly stated) include:
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Lack of color profile support
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Specifications still under review (format not well-established, standard development ongoing)
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Reduce storage costs (though a major consideration in other institutions), is not a major issue for our archive (at this time) as we do not produce significant tiff files on a massive scale to benefit on storage savings
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Lack of capture mechanism (JPEG2000 must be converted from TIFFs)
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Research use of JPEG2000 as an access version only for enhanced online experience
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Investigated and tested format versions (JP2 vs JPK), multiple conversion software and various specification parameters
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Design batch processing workflow to provide consistency in creation of files and efficiency of file creations
Selected Bibliography
https://www.zotero.org/groups/jpeg2000_bibliography
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