[Lowfer] Post Capture Processing (was: XSR in CT)

[John Davis]

>PCP = post capture processing (no drug usage here!). While not
>spectacular by any means , it may point up an area for some further
>study.
>
>Jay Rusgrove, W1VD
>

Jay,

Post capture processing does indeed show potential.  I've used gamma
correction (available even in some free graphics programs), coupled with
brightness, contrast, and sometimes even color adjustments, to manually
enhance ARGO captures for printing, and also sometimes to make the originals
"readable" where it was otherwise hard to distinguish between noise and
signal.

I first tried it a couple of years ago on some early European ham QSO
captures where it was hard to be sure what was hiding there in the
background.  By using gamma correction tools to "stretch" the contrast in
only the most important part of the transfer curve (determined on a
case-by-case basis), I found it was often possible to make a questionable
signal quite readable.

A hint to anyone trying this: start with at least 24-bit color images to
ensure good resolution between differing values.  Sometimes the subtle
changes are what count the most, so you want to preserve maximum color depth
until you have the signal well isolated.  Then you can reduce the color
depth or gray scale values for convenience.

As Jay says, it is an area for further study.

John