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Streaming and JPEG2000 Compression for use in Uncompressed Image Archives. Lev Weisfeiler Aware, Inc. Archives of Uncompressed Images. Data stored uncompressed in PACS 2000x2500 CR Total Image size: 10MB 512x512 CT Total Image size: 0.5 MB - PowerPoint PPT Presentation
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Lev WeisfeilerAware, Inc.
Streaming and JPEG2000 Compression for use in Uncompressed Image Archives
Streaming and JPEG2000 Compression for use in Uncompressed Image Archives
Archives of Uncompressed ImagesArchives of Uncompressed Images
Data stored uncompressed in PACS
2000x2500 CR
– Total Image size: 10MB
512x512 CT
– Total Image size: 0.5 MB
Great for fast networks since no time spent on decoding
Lossless data quality
Viewing Images over Slower NetworksViewing Images over Slower Networks
User connecting over slower link may prefer compressed
data, to minimize time to display of full fidelity images
Total time to display =
compression time on server +
transmission time +
decompression time on client
Streaming of Compressed DataStreaming of Compressed Data
The total time can be reduced if any of these processes
can be done in parallel
Streaming: decompression and transmission can be
interleaved
– data is decompressed and displayed progressively, as it is
received, without waiting for full image data
Compression and transmission can be interleaved as well
JPEG StreamingJPEG Streaming
JPEG encodes data in blocks of 8x8 pixels;
Blocks can be transmitted as they are encoded, without
waiting for the rest of the data.
– Precludes the use of the progressive mode of JPEG
• In progressive mode, the DC terms from each block are
grouped at the front
– Image can be progressively decoded in 8 row chunks,
essentially appearing line-by-line from top to bottom.
A significant proportion of the image data is necessary for
a meaningful first view
JPEG2000 Progressive EncodingJPEG2000 Progressive Encoding
Progressive Encoding By Quality
– Image is processed by the wavelet transform
– First quality layer is produced by encoding some of the
wavelet transform data; the layer is transmitted in a “tile part”
• “tile part” is a JPEG2000 codestream unit
– Process repeated for production of next layer
Progressive Encoding By Resolution
– Image is processed by the wavelet transform
– The lowest resolution data is encoded and transmitted in a
tile part
– Process repeated for production of next resolution data
JPEG2000 Progressive EncodingJPEG2000 Progressive Encoding
Progressive Encoding By Color Channel
– First color channel is processed by the wavelet transform,
fully encoded, and transmitted in a tile part
– Process repeated for production next channel
Progressive Encoding By Spatial Region
– In a tiled image, each tile can be processed and transmitted
independently
– In an untiled image, precincts are defined for the image and
are encoded in their proper order, with each one being
transmitted once it is fully encoded
• Precincts are a spatial division of the wavelet transform data
CR ExampleCR Example
Network: DSL 2Mb/sec, 50% utilization, 10% overhead
2500x2048 CR 10MB Uncompressed
– Transmit time ~ 90 seconds
– Total time to display: 90 seconds
2500x2048 CR Losslessly Compressed (4MB)
– Compression:1.77 sec
– Decompression: 1.44 sec
– Transmit time ~35 seconds
– Total Time to display: ~39 seconds
CR ExampleCR Example
2500x2048 CR Losslessly Compressed with 3 Quality Layers– Thumbnail: 70KB
– Visually lossless (20:1) : 540KB
– Lossless: 3.4 MB
Progressive Encoding Time:– Layer 1: 0.42 sec
– Layer 2: 0.41 sec
– Layer 3: 1.08 sec
Decompression Time:– Layer 1 only: 0.14 sec
– Layer 1 and 2: 0.35 sec
– All three layers: 1.45 sec
Time to View:– Layer 1: (0.42 sec + 0.6 sec + 0.14 sec) ~= 1.2 seconds
– Layer 1 and 2: (0.41 sec+ 5 sec +0.35 sec) ~= 6 seconds
– All three layers: (1.08 sec + 30 sec +1.45 sec) ~= 33 seconds
CT ExampleCT Example
Network: DSL 2Mb/sec, 50% utilization, 10% overhead
512x512 CT 500 KB Uncompressed
– Transmit time ~ 4.5 seconds
– Total time to display: 4.5 seconds
512x512 CT Lossless Compressed 1 layer: 130 KB
– Compression: 0.13 sec
– Decompression: 0.10 sec
– Transmit time 1.1 seconds
– Total Time to display: 1.33 seconds
CT ExampleCT Example
512x512 CT Lossless Compressed 3 Layers– Thumbnail: 10 KB – Visually lossless (25:1) : 20 KB– Lossless: 130 KB
Compression: – Layer 1: 0.08 sec (encoding + x-form time)– Layer 2: 0.02 sec (encoding only) – Layer 3: 0.03 sec (encoding only)
Decompression:– Layer 1: 0.05 sec– Layer 1+2: 0.06 sec– Layer 1+2+3: 0.10 sec
Time to View:– Layer 1: (0.08 sec + 0.09 sec + 0.05 sec) ~= 0.22 seconds– Layer 1+2: (0.02 sec+ 0.18 sec +0.06 sec) ~= 0.26 seconds– Layer 1+2+3: (0.03 sec + 1.17 sec +0.10 sec) ~= 1.3 seconds
Adaptable ProcessAdaptable Process
JPEG2000 encoding progressions can be mixed
– E.g.: First resolution and then quality progression orders
would have the lowest resolution data progressively encoded
by quality and transmitted, followed by the next resolution
Granularity of the interleaving of the compression process
and the transmission process can be adapted for:
– time to first image display
– time to full image display.
Optimized based on:
– application needs
– relative loads on the processor
– network speed
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