Global Mapper Pro

Export from a lot of png files

GuellerGueller Global Mapper UserTrusted User Posts: 11
edited June 2014 in Technical Support
Hi @all

My Problem: At the last few days i downloadet a lot of files from a wms sever and saved as png files. It Are 24'748files in totali 2.54GB

Now i creat a map catalogue and now i will export to 1 ECW File. After 30seconds GM will give me a error " Unknow Error loading PNG File "

Can some one help me ?

Greetings Michel

Comments

  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited May 2014
    Michel,

    What version of Global Mapper are you using? If you open the Task Manager are you running out of memory? The map catalog should handle loading and unloading the PNG files as needed. Are they all positioned in a mosaic, so only a few should be needed open at once for a single row of the output ECW file, or are they maybe positioned wrong so they all stack on top of one another and would all try to load at once?

    Thanks,

    Mike
    Global Mapper Guru
    geohelp@bluemarblegeo.com
    Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation
  • GuellerGueller Global Mapper User Trusted User Posts: 11
    edited May 2014
    Hello Mike

    I use the GM Version 14 on my Laptop. The Ram Memory shows on 1.7GB for 2%-3% of Export to ECW. After this suddenly the RAM Memory goes over 2.7GB an then comes the Error.

    The second Question i don't understand what you mean with positiones in a mosaic od wrong positioned...?

    Greetings Michel
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited May 2014
    Michel,

    The error is certainly coming from an out-of-memory condition then. When you load your map catalog, are the maps all tiled out so that you can zoom in on them until they show and you then get a seamless mosaic or do you just see one map box in the middle? Or are they perhaps all lined up in a single row so that the export would have to load all of them at once to export a single row?

    Thanks,

    Mike
    Global Mapper Guru
    geohelp@bluemarblegeo.com
    Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation
  • GuellerGueller Global Mapper User Trusted User Posts: 11
    edited May 2014
    Hi Mike

    After loading Map Catalogue i see Picture 1 and then i can zoom it and after this i see Picture 2 the diffrent tiles or when i zoom littel bit nearer the little maps

    gm.jpggm1.jpg
    gm.jpg 489.5K
    gm1.jpg 559.4K
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited May 2014
    Is it possible for you to try the latest v15.2 trial from Global Mapper Downloads and see if it has the same issue? You can email your machine ID to geohelp@bluemarblegeo.com and we can provide a less limited trial if the export size is reported as too large for the built-in trial.

    Thanks,

    Mike
    Global Mapper Guru
    geohelp@bluemarblegeo.com
    Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation
  • GuellerGueller Global Mapper User Trusted User Posts: 11
    edited June 2014
    Now it works. Was to much files for my Laptop. After i make 1 PNG file with 90 other PNG Files and so going on until i have 6 files. With 3.8GB Data.

    Now i have generate one EWC File with 1:10. The ECW File works. But its so big with 4.96GB. Why this? I had compresses 1:10 so i understand the new file must be 380MB ?

    Greetings Michel
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited June 2014
    Michel,

    The target compression ratio for ECW isn't exact, it will be an approximate amount of compression to try for from the uncompressed size of the data. How much it actually compresses will depend on the data itself.

    The PNG format is already compressed, so even if ECW got exactly 10:1, it wouldn't be 10 times smaller than the size of the PNG files, but 10 times smaller than the uncompressed data from the PNG, like the same of a BMP file. The PNG format can compress certain types of maps very well, like scanned maps with a limited color palette, whereas ECW does a much better job on things like imagery with a large number of colors. So depending on the type of data you have you might actually get better compression with a lossless PNG files than you do using a lossy ECW file, especially since the ECW will store additional zoom layers of content internally to make display faster when zoomed out.

    Thanks,

    Mike
    Global Mapper Guru
    geohelp@bluemarblegeo.com
    Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation
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