[ka-Map-users] problem with compressed images

Michael Schwarz mschwarz at stud.hs-heilbronn.de
Mon May 21 12:14:06 EDT 2007


hi...
ecw file format works right well for me! thanks a lot, Pēteris ...

now i want to measure performance of kamap by using ecw  vs. jpg images.
but it's not enough to say it's fast. i have to prove it!
may you tell me a tool to get the time which the browser needs to load
the map with kamap?

Michael Schwarz

Pēteris Brūns schrieb:
> Try to use ecw file format or tile your JPG images to smaller
> images/tiles and use as tileindex in mapfile. Butt better use tiled
> data as tif-it works faster.
>
> pb
>
>
>
> Michael Studium wrote:
>> Dear list,
>> we work with quite big images( JPG ~600 MB) which we would like to
>> display with Mapserver.
>>
>> Using CGI-parameters it takes a very long time until we see the
>> picture on the bowser.
>> Therefore we decided to use kamap-tools , because of the support of
>> precaching to speedup.
>> But we discovered that compressed images like JPG are only displayed
>> up to the size of 40 MB. The cgi-bin processes has been using all the
>> cpu capacity and even after long period they did not finish.
>> We had no problems with uncompressed images. But the TIF format is
>> only designed for a size up to 2 (4?) GB, so this doesn't work for
>> our data.
>> We want to know why compressed images have such limits? And of course
>> what can we do to get kamap working? and if there is no way: what is
>> the reason for?
>> we are running:ms4w with default configurations
>>
>> Our mapfile:
>> MAP
>>     SIZE 400 300
>>     IMAGETYPE PNG
>>     EXTENT 0 0 57344 16384
>>     STATUS ON
>>     WEB
>>         IMAGEPATH "C:\ms4w\tmp\ms_tmp\"
>>         IMAGEURL "\ms_tmp\"
>>     END
>>     LAYER
>>         NAME "Example"
>>         TYPE RASTER
>>         DATA "example.jpg"
>>         STATUS ON
>>     END
>> END
>>
>> thanks a lot
>> Michael Schwarz
>>
>>
>>
>>
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>> ka-Map-users at lists.maptools.org
>> http://lists.maptools.org/mailman/listinfo/ka-map-users
>>
>>   
>
>
>
>


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