[mapserver-users] Output image resolution - explanation needed

[Dejan.Gambin at pula.hr]

Hi,

I am trying to download a high resolution image and print it on a paper. I 
am using p.mapper and its download function that enables downloading the 
map image on different resolutions. 

I have turned on my raster layer (ortophoto image). I have zoomed in to an 
area of interest. I have downloaded the map twice - with a resolution of 
150 and 300. The image is shown i a new page/tab (firefox). I right click 
on the image and save it as a png (also tried with a jpeg) file. Now, the 
first file is 2150x1111 pixels, 120 dpi vertical and horizontal resolution 
(right click on a file, properties, summary, what does it mean?), the 
second file is 4300x2222 pixels, 120 dpi vertical and horizontal 
resolution. Seems ok. The second image is "doubled" in pixel size.

Now, when I try to print this image on A4 paper, using 300dpi, the images 
are the same, there is no "better quality" in second image.

I have just finshed reading the Mapserver thread on "Change image 
resolution in mapfile". Several limitations are mentioned there - max. 
image size supported by Mapserver, "resolution" value/tag embedded in 
output format, etc. Can it be related to my problem? Or is it maybe that 
software I am using to print this image doesn't "use" this extra pixels? 
Or I am just missing some basic stuff I need to know :-(


thanks very much on any explanation

regards, dejan
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.osgeo.org/pipermail/mapserver-users/attachments/20080730/756ea464/attachment-0001.html