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[aprssig] APRS Multi-Mode Tracker

'Scott Miller' scott at opentrac.org
Mon Mar 5 03:41:11 UTC 2007


>JPG is only intended for continuous-tone images; i.e. photos. It applies
image compression by looking for gradual gradients of brightness and color
from groups of adjacent pixels. 
 
Actually, it generally transforms the image to a YCbCr color space, applies
chroma subsampling, then performs a discrete cosine transform on each 8x8
pixel block in each channel, quantizes the resulting coefficients, and uses
entropy coding to store them with run-length encoding and Huffman
compression.  But yeah, it makes straight lines and edges look fuzzy.  =]
 
 > 2)    What you are striving for is not a "multimode tracker" but a
full-function APRS station that happens to be mobile.  The commonly-accepted
usage of the term "Tracker" is for a dumb (or should I actually say deaf")
transmit-only mobile that spews out posits periodically and can't receive
anything.

The Tracker2 does pretty well for mixed PC and standalone operation.  I
haven't implemented a GPS pass-through yet, but I could. 
 
Scott
N1VG
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