20000615: CM2000-001 McIDAS enhancements, stretches and RedHat 6.x Linux support

>From: Craig Motell <address@hidden>
>Organization: University of Hawaii
>Keywords: 200006151841.e5FIfBT09761 McIDAS stretch enhancement

Craig,

>I have a sorta poor question to ask because I don't
>have the exact details. IF this question is not
>percise enough, I will ask later when I have
>mcidas in front of me.
>
>I want to enhance an 8 bit image. I want to
>have the counts 30 60 spread out to take the whole
>image, like this
>
>counts 0 to 29 mapped to 0
>30 to 50 mapped to 1 to 254
>counts 51-255 mapped to 255

OK, it seems like this should be easy enough, but you never know.

>I tried a command like EB 30 50 1 255
>I think that is the command i used.

Looks correct for stretching the values from 30 to 50, but this will
not address the brightness values < 30 and > 50.

>But the command refused to map like I wanted.

>Can you tell me how to achieve the mapping that I want?

I tried several combinations of EB and EU, but the closest I could
come to the exact mapping you want was:

EB 30 50 0 255
EB 51 255 255 255
EB 0 20 0 0
EU TABLE
 Brightness  Blue      Green      Red
  min max   min max   min max   min max
  --- ---   --- ---   --- ---   --- ---
    0  30     0   0     0   0     0   0
   31  50    13 255    13 255    13 255
   51 255   255 255   255 255   255 255
EU: Done

Looks like the code makes a decision about how many levels can be fit
into the output range and adjusts the brigtness break points accordingly.

The other way to attack this is to us a stretch table:

SU INI 3050 VISR BRIT
SU: DONE
SU MAKE 3050 30 50 1 254
SU: DONE
SU TABLE 3050
BREAKPOINTS STORED IN TABLE : 3050.ST
INPUT       OUTPUT
-----       ------
 30            1
 50            254
CALIBRATION TYPE  : VISR
CALIBRATION UNITS : BRIT
BAND NUMBER       : -1
INTERPOLATION TYPE: LIN
SU: DONE

You then load the image specifying EU=IMAGE SU=3050 (or whatever name
you choose for your stretch table.  I think that this should get you
where you want to be going.

>---------------------------------
>
>Question 2: I looked for mcidas version to run on
>Red Hat 6.X, I believe Tom Yokas has this version.

Yes, Unidata supports McIDAS-X on RedHat 5.x and 6.x Linux.

>Is there a mcidas 6.X?

The current release of  Unidata McIDAS-X is 7.612 (there never was a
version 6.x; SSEC jumped from 2.102 to 7.0).  This version runs on
RedHat 6.x Linux, so this is what you should grab.  By the way,
I am working on the 7.70 release of Unidata McIDAS, and it looks to
have several features that make McIDAS easier to use especially in
the area of accessing imagery in AREA file format, but not named with
the archaic AREAnnnn naming constructs.

>Sincerely, 
>Craig Motell

Tom Yoksas

>From address@hidden Thu Jun 15 18:01:15 2000
>Subject: Re: 20000615: CM2000-001 McIDAS enhancements, stretches and RedHat 
>6.x Linux support

Thank you Tom,

As always I appreciate your precise responses
to my vague questions.

sincerely,
Craig