[mapserver-users] Raster Data

[Andy Colson]

On 3/12/2014 9:42 AM, jcwalz wrote:
> Hello,
>
> I have a png raster image that I am adding to GeoMOOSE and it is about 3GB
> in size. It takes about 10 minutes for the image to show up because the file
> is so large. What is the best way of dealing with large images like this?
>
> Thanks,
>
> Jenna
>
>

I'm assuming that file has no overlays, so it has to read the entire file.

Converting it to ecw or sid will compress the file and make it faster to 
render at different zoom levels.  ecw and sid might require $$ though.

Another alternative is to use jpeg encoded tiff, which will create a 
smaller file, and then build overlays on top of it.

I'm using something like this to convert my imagery:

gdal_translate -of GTiff -co compress=jpeg -co JPEG_QUALITY=80 -co 
PHOTOMETRIC=YCBCR -co tiled=yes -co bigtiff=yes 
../ecw1/ortho_1-1_1n_s_sd031_2012_1.ecw  ortho_1-1_1n_s_sd031_2012_1.ecw.tif


gdaladdo -ro --config COMPRESS_OVERVIEW JPEG --config 
PHOTOMETRIC_OVERVIEW YCBCR --config INTERLEAVE_OVERVIEW PIXEL 
ortho_1-1_1n_s_sd031_2012_1.tif 2 4 8 16 32 64


Thats two commands.  Each command should be all one one line.  I have 
had some problems with my overlays being larger than 4 gig.  (gdaladdo 
does support --config BIGTIFF_OVERVIEW YES, but I've had problems with it)


-Andy