[Mapserver-users] Mapserver and POSTGIS and RASTER layer

Paul Ramsey pramsey at refractions.net
Fri Apr 25 14:02:59 EDT 2003


Rosangela,
If there is any way you can convert your raster data to TIFF instead of 
JPG you will find your performance is much improved. Mapserver can 
quickly do random access of data within TIFF files, but for "naive 
compressed" formats like JPEG and PNG it has to uncompress the whole 
file before it can access particular areas of the image. For larger 
images this can cause a great deal of overhead and slow things down alot.
Paul

Rosangela Silva wrote:
> Paul,
> I did a test with TILEINDEX and shape files and it's running. (Good!!)
> I think that (for while) it's solve my problem with mapserver and raster
> data.
> I don't know yet about performance, but I do some more testes and with
> jpg files too.
> Thanks
> Rosângela.
> ----- Original Message -----
> From: "Paul Ramsey" <pramsey at refractions.net>
> To: "Rosangela Silva" <rosangela.silva at zenitpolar.com.br>
> Sent: Wednesday, April 23, 2003 9:31 PM
> Subject: Re: [Mapserver-users] Mapserver and POSTGIS and RASTER layer
> 
>>Ah. Now *that* is possible with current mapserver. You do not get to
>>manage your data in a database, but it can be done. You will want to
>>create a "tiled" data set. I believe that gdal includes a utility to
>>turn a set of images into a shape index tile which can be used to create
>>a tiled raster layer. I have used this to create a complete hillshading
>>of BC out of 350 raster files.
>>
>>Rosangela Silva wrote:
>>
>>>Unhappyly I cannot finance the development of this project, but I need
> to find a solution for this problem in a short time. Does someone have this
>>>problem???
>>>But is possible in Mapserver do something like this:
>>>LAYER #Raster
>>>NAME "sp_images"
>>>=>>>DATA "sp1.tif"  AND "sp2.tif" AND "sp3.tif"   ????
>>>STATUS DEFAULT
>>>TYPE RASTER
>>>END

-- 
       __
      /
      | Paul Ramsey
      | Refractions Research
      | Email: pramsey at refractions.net
      | Phone: (250) 885-0632
      \_




More information about the mapserver-users mailing list