PDS_VERSION_ID = PDS3
RECORD_TYPE = STREAM
OBJECT = TEXT
PUBLICATION_DATE = 2010-09-15
INTERCHANGE_FORMAT = ASCII
NOTE = "Description file referenced by LOLA JP2 PDS labels"
END_OBJECT = TEXT
END
JPEG2000 Standard -
The LOLA GDR data products are stored in the JPEG2000 lossless-compressed
format (http://www.jpeg.org/jpeg2000/) as well as PDS IMG format with detached
labels. This format allows for geolocation information in addition to the data.
Advantages include excellent compression performance, multiple resolution
levels from a single image data set, progressive decompression quality
layers, lossless and lossy compression (LOLA GDR products use lossless
compression per the PDS Standard).
These features are achieved by the use of a sophisticated image coding
system based on discrete wavelet transforms (DWT) combined with other
coding techniques to generate a JPEG2000 codestream that can be rendered to
image pixel rasters using inverse transform algorithms.
The PDS Standard specifies that a JPEG2000 codestream will be stored in a
"JP2" file as described by the JPEG2000 Part 1 standard [1, Appendix I].
This file format encapsulates one or more codestreams plus characterizing
metadata in a contiguous sequence of binary data "boxes". The first two
boxes of a JP2 file must be Signature and File Type specification boxes
that uniquely identify the file as a JP2 file. This must be followed by a
JP2 Header box that contains sub-boxes that characterize the Codestream
box that follows with information such as the image dimensions, pixel
datum precision, compression technique and color space mapping for image
display purposes. The JP2 file may also contain additional boxes that
contain UUID (universally unique identifier) signatures, URL (uniform
resource locator) references, and XML (extended markup language)
sequences that can be used as desired by the data provider.
Each LOLA JP2 product is associated with a file with the extension
[product]PPD_AUX.XML for cylindrical projections at 2^n pixels per degree
(PPD) or
[product]MPP_AUX.XML for polar projections at nnn meters per pixel (MPP).
The file must be renamed to [product]PPD.JP2.AUX.XML to be recognized by
some geospatial programs as a raster histogram and scale file.
The metadata keywords
-3.27680000000000E+04
0
0.5
as well as
, , , , and statistics
will then be recognized.
The JPEG2000 image coding techniques are sensitive to byte ordering (for
multi-byte data) and signedness of the image data. LOLA GDR image data
are MSB ordered and unsigned.
JPEG2000 Software -
Part 5 of the JPEG2000 offers reference software implementations of the
Part 1 core-coding standard. The JasPer Project provides a C language API
and demonstration applications
(http://www.ece.uvic.ca/~mdadams/jasper/). JJ2000
(http://jj2000.epfl.ch/) provides pure Java classes. Both of these
implementations are employed in two J2K plugins for the Image I/O Tools
from Sun Microsystems' Java Advanced imaging (JAI).
(http://java.sun.com/javase/6/docs/technotes/guides/imageio/)
(http://java.sun.com/javase/technologies/desktop/media/jai/)
Dr. David Taubman, one of the principal JPEG2000 standard developers,
implemented the Kakadu software. Kakadu offers a full range of
application utilities and highly optimized C++ classes
(http://www.kakadusoftware.com/).
The JP2_Info utility, in the Image_Tools package of the PIRL Java
Packages
(http://pirlwww.lpl.arizona.edu/software/PIRL_Java_Packages.shtml)
provides a detailed report on the contents of a JP2 file.