[Xastir-Dev] New geo file tags

[Gerry Creager N5JXS]

Cool!  Thanks, Chris.

And, now the bad news: Until I can figure out why my LDM ingest system 
is having problems, or can alleviate these problems with another system, 
the US composite is off the air.  I may regenerate it on an hourly 
basis, if I can get some relief on an ingest problem, but it's not going 
back to 6- or 12-minute status for at least a few days.  After we beat 
it up here, I'll release it to the APRS community and the OpenGIS 
community as a whole.

73, all, gerry

Chris Bell wrote:
> To go along with Gerry Creager's wonderful new image, here is some code to 
> make it prettier, along with the other regular NWS radar images.  
> 
> Two new tags for the geo files:
> 
> TRANSPARENT and CROP
> 
> Transparent is a first cut at adding transparencies to images on the
> fly, it needs to be enhanced to allow a list of colors to zap.  Right
> now, setting it to "1" will zap the black background in the NWS and
> Gerry's radar images.   (hard coded in the source)
> 
> Crop defines a set of border pixels to chop off (actually make
> transparent).  It will be recoded soon to make it more efficient, as
> part of my projection project.  So, to use it, just define the
> (x1,y1,x2,y2=left,top,right,bottom) values to cut off.  [(0,0) is
> upper left.]  For example, if I had an image of 100x100 pixels, and I
> wanted to take off 10 pixels off each border, I would use
> 
> CROP 10 10 90 90
> 
> This does not affect the tie point georeferencing.
>  
> For the regular NWS radar images that are 620x620 pixels with the
> description text at the top and bottom, and the color index on the
> left, I am using:
> 
> PROJECTION TM
> REFRESH 300
> TRANSPARENT 1
> CROP 35 20 616 600
> 
> (and removing the "NEGATE 200") The projection is not right, but it is
> better than without it.  My modified geo file for Gerry's image:
> 
> --------------------
> #US Composite Radar image (Unidata/LDM/Gempak) n5jxs 2003 08 25
> URL	http://page4.tamu.edu/images/01_USrad.png
> #		X	Y	Long		Lat
> TIEPOINT	200	200	-123.00000	48.00000
> TIEPOINT	5800	2300	-67.00000	27.00000
> IMAGESIZE 6000 2500
> REFRESH 720
> TRANSPARENT 1
> --------------------
> 
> I was having trouble with the ftp URL as well, so switched to the
> http, works great!   
> 
> [Gerry, what is the projection of your composite?  I will soon have
> proj4 support, so we can handle anything... :) ]
> 
> 
> Have fun!!!!!
> 
> Chris.
> KD6ZWR
> cbell at junknet.com
> _______________________________________________
> Xastir-dev mailing list
> Xastir-dev at xastir.org
> https://krypton.hscs.virginia.edu/mailman/listinfo/xastir-dev

-- 
Gerry Creager -- gerry.creager at tamu.edu
Network Engineering -- AATLT, Texas A&M University	
Cell: 979.229.5301 Office: 979.458.4020 FAX: 979.847.8578
Page: 979.228.0173
Office: 903A Eller Bldg, TAMU, College Station, TX 77843