HyperDAAC Tools
The tools are extras. They are not required for any of the
HyperDAAC functions. They are provided as-is and with little or
no documentation. If you're not a programmer, don't even try
to use them!
Running any of these with no commandline options will give you a
brief Help screen.
- 16to8
- Converts 16-bit AVHRR bands to 8-bit for browse products. Note
that you can define SWAB to swap bytes, if you have obtained data
in the wrong byte-order format for your processor.
- addhdr
- Adds an arbitrary Header to a HyperLens Image (.hli) file.
- downsample
- Downsamples an image. Pixel values are chosen by area averaging or
by voting (maximum count) or a mixture of the two:
- For Classification bands you should always use voting
- For continuous-tone images use area averaging
- For continuous-tone images with certain pixel-mask values, use a hybrid.
The HyperDAAC AVHRR bands must have values 0,1 and 2 (no-data, ocean, and
interrupted area masks) excluded from area averaging.
- imgstats
- Computes a histogram
- merge
- Merge two or more image using max-value
- rawimg
- Converts a raw 8-bit bitmap image to HyperLens Image (.hli) format.
(Note: HyperLens® can read standard formats such as GIF and JPEG too).
- scene.cgi
- Generate HyperLens Definition (.hld) and HyperLens Image files
as CGI when running HyperLens® as an Applet. Note that the server
must send the image files as-is - for example using mod_asis
with the Apache webserver.
On some systems, using the Applet/CGI architecture may offer significant
speed improvements. scene.cgi uses the C programs gzip
and rawimg to read the raw data, with a consequent x30 speed
improvement over JAVA input on a Linux platform.
See Also