Compression in TIF files: disk space vs. performance

[Armin Burger]

Andreas,

I made once quite good experiences with scanned b&w images using the Fax 
Encoding (CCITT) Group 4 TIFF compression. The images had no overviews, 
but were also just shown at a scale that was reasonable for the details 
on them. The compression was typically good, something like 3 to 5 times.

Armin

Andreas Neumann wrote:
> Hello list,
> 
> I have a question on compression in tiff files.
> 
> I read that for best mapserver performance it is recommended to store 
> tiff files on the server in uncompressed format. We currently have a 
> disk space problem and need to serve a large number of raster images. Is 
> there any compression technique that allows to save diskspace while 
> maintaining a reasonable or good performance? Or is compression not 
> recommended at all?
> 
> Another question: we need to serve 1bit (b+w) rasterimages that are 
> delivered as gray/rgb jpegs later because we want to use resampling. 
> What is the best color depth to store the original images. I noticed 
> that when keeping them in 1bit color depth one cannot create pyramids 
> using gdaladdo. Is it better to store them in 1 bit with no pyramids or 
> in 8bit gray value with pyramids?
> 
> Thank you for any help on my questions,
> 
> All the best,
> Andreas
>