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Increasing Image Transfer SpeedIn MSAT Through Image
Compression
David Elies
Akimeka, LLC
Advisor: Steve Schweibinz
Mentor: Rob Reed
Overview
• Medical Situational Awareness in Theater
• NASA WorldWind
• Download speed and image compression
• DDS files
• Transparency
• Conclusions
Medical Situational Awareness in Theater(MSAT)
• Provides military medical decision makers with timely, relevant information
• Assembles information frommultiple sources
• Allows users to view exactly the datathey need
• Can use existing and future data sources
NASA WorldWind
• Global visualization software
• Similar to Google™ Earth
• Open Source
NASA WorldWind
NASA WorldWind
NASA WorldWind
NASA WorldWind
Slow Image Downloads
Increasing Transfer Speed by Decreasing File Size
Increasing Transfer Speed by Decreasing File Size
• Images are
512 x 512 pixels
Increasing Transfer Speed by Decreasing File Size
• Images are
512 x 512 pixels
• .dds compressed
file size – 256KB
Increasing Transfer Speed by Decreasing File Size
• Images are
512 x 512 pixels
• .dds compressed
file size – 256KB
• .jpg compressed
file size – 24KB
Decoding the .dds file format
example.dds
Decoding the .dds file format
• Binary01000001010010110100
00010100110101000001
01001001001000000100
10010100111001010100
01000101010100100100
1110
example.dds
Decoding the .dds file format
• Binary
• Consists of:• Header• Body Body
Header
example.dds
Header
Decoding the .dds file format
• Binary
• Consists of:• Header
• Height• Width• Pixel format• Compression
type indicator
example.dds
Header
Decoding the .dds file format
• Binary
• Consists of:• Header• Body
• Image pixelsData
example.dds
Body
Converting the .dds file format
• .dds file is read
• Image is created in memory
• .jpg file is created
01000001010010110100
00010100110101000001
01001001001000000100
10010100111001010100
01000101010100100100
example.dds
01100001011010110110
10010110110101100101
01101011011000010010
11000010000001101100
0110110001100011
new.jpg
Transparency
Transparency
• .dds files use transparency
Transparency
.jpg files do not
Transparency
• Recognize formerly transparent pixels (by color)
Transparency
• Recognize formerly transparent pixels (by color)
• Convert back to .dds, using transparency for specified color
Transparency
• Transparent color may be part of image as well.
Transparency
• Transparent color may be part of image as well
• Transparent pixels may be different colors
Conclusions
.dds images can be transmitted as .jpg
Transmission time was decreased
Transparency was mostly preserved
Some image quality was lost, but loss is negligible
What is the impact on processing speed?
Can we convert files directly w/o intermediate steps?
Can we guarantee proper handling of transparency?
Acknowledgments
Akimeka, LLC Akamai Workforce Initiative
Deanna Garcia Lani Lebron
Steve Schweibinz Lisa Hunter
Rob Reed
The rest of the MSAT team Akamai Instructors
Maui Community College Nina Arnberg
Mark Hoffman Mike Nassir
Jung Park Dave Harrington
Elizabeth Reader Mike Foley
Mark Pitts
The 2009 Maui Akamai Internship Program is funded by the University of Hawaii, the Department of Business, Economic Development, and Tourism, the National Science Foundation Center for Adaptive Optics (NSF #AST - 9876783).
