Best Image/Map Export Formats to use between software packages?

[DarkMushroomGames]

Hi all,

Noob Q re the best format(s) to work with when exporting between various mapping/dtp software packages?

ie so you don't lose details etc when bringing larger scale maps/images across from one s/w package to another?

We work with Adobe Creative Suite (Illustrator/Photoshop/Indesign etc) so when requesting maps etc that were created with other applications/software packages what is the best format to request artifacts in?

TIF ? PDF ?

So I can pull together an accurate commission brief.

thanks in advance

regards,

Nick

[Gidde]

I switch between Photoshop and GIMP a lot, and I find .png to be the easiest to work with when moving flat layers from one to the other. It keeps the alpha channel without losing anything in translation (just set it to the highest quality).

[Redrobes]

PNG is excellent choice. It doesnt have a quality setting since its lossless. There is no loss of quality - unlike JPG where you set the desired quality - or loss of.

[Gidde]

Huh. GIMP always makes me choose a quality 1-9 when I export to a png.

[ltan]

Gidde: I think it is "Compression level"? I thought it was Quality as well until I read it just now.

[Gidde]

So it is! Thanks for clearing that up. Redrobes, can I take that to mean that compression != loss of quality with a png?

[Redrobes]

I have not seen an app give any options for compression for PNG others than this. From reading around posts and stuff on the web the consensus appears to be that all the final images from any compression setting will be the same but that the computer will do more work looking for a smaller set of numbers to describe it with higher compression level. I.e. it works harder to find you a smaller file size but that the image is exactly the same no matter what. I think the LZ algorithm recurses around a loop a few times getting the file smaller (progressively less) each time and that you can go around 1 time or 9 times or maybe the 1 to 9 represents a set of loop counts which are actually much higher. So if you don't mind a seconds extra wait then set it always to 9. Maybe no one but GIMP cares about that extra second and just sets it to max. And also note that decompressing a file take the same time no matter what compression level. The effort is only taken to find the compression tables at compress time.

Now if you choose indexed mode etc then ok its gonna be a whole lot different image and much smaller as per my tech guide, so dont do that. Also saving out creator information, gamma and other meta information might add a few bytes to the file too but nothing too significant.

So you can leave it at the default or whack it up to 9 or whatever but I don't think it makes any difference.

[johnvanvliet]

the choice is easy
for a DEM a 32 bit float tiff
that can easily be converted to a 16 bit signed image and to a FITS or RAW or left as a 32 bit tiff

a color texture
portable pixel map " ppm" or Portable network graphics "png"
both support 8 bit uchar and 16 bit ushort

As to png compression
i set it to 3
there is no real advantage of sitting there waiting for a 32768 x 16384 pixle image to open from a 9 and only be 10 meg smaller but take 10 minutes to open

[Midgardsormr]

If you're interested in a general rundown of image export filetypes, I wrote a guide on the subject a while back: http://www.cartographersguild.com/so...t-formats.html
A related topic of interest is Redrobes' http://www.cartographersguild.com/tu...explained.html