[kismac] Re: map question

  • From: ard.jonker@xxxxxxxxx
  • To: Doug Tallacksen <dougtallacksen2@xxxxxxxxxxx>
  • Date: Tue, 2 Sep 2003 21:50:55 +0200

>2) Ard, you mentioned you have a useable map that can do 9x zooming.
>Wow!  Can you give details on the size, resolution, etc?

I happened to have a large, single sheet map available that covered 
the whole city in about 4 A4-sized submaps. Using an image 
maniputlation program, I moved the four parts about till they were a 
nice stitch without too much visible seam. As the map was detailed, 
the images were scanned at 300 dpi, and A4 is roughly 11x8 inches, I 
had 22x16 inch x300 dpi, so  roughly 6kx5K. Clipping the odd harbour 
sites  that were of no interest, I was left with about 5K pixel 

When running Kismac, I guess the average map size visible in my 
personal user environment is about 500x500 pix so that allows 10x 
zooming. Give or take a factor 2 here or there. Nothing fancy I 
guess. The whole map was some 100 MB during scanning and stitchnig 
(uncompressed TIFF) but once I cut back to usefull size, reduced to 
indexed 16 colors, applied lzw compression, I was down to 3 MB and 
was left with a spotty map with flakey colors.

The best appearance, then, was when I changed the size of the 
original stitch to jpg compression (recursive error correction 5x) 
with a resolution of 3Kx3K at 72 dpi, yielding about 12 MB as map 
size in Kismac.


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