[gdal-dev] Tiling and Overviews disappear after compressing with LZW

[Vincent Schut]

On 12/05/13 16:21, Ammar wrote:
> Hello list,
>
> I am new to GDAL and I have been using the utilities to process and 
> prepare TIFF  to create a mosaic in Geoserver. I am expermineting with 
> different compression methods and I have noticed that after 
> compressing a file with LZW, the previously created tiles and 
> overviews disappear!
>  what I did was:
>
> gdal_translate -a_srs "EPSG:3011" -co "TILED=YES" -co "BLOCKXSIZE=512" 
> -co "BLOCKYSIZE=512" in.tif out.tif
>
> gdaladdo -r average file.tif 2 4 8 16 32//Adding the overviews
>
> gdal_translate -co compress=LZW in.tif out.tif
>
> After the compression, I got the original block size and with no 
> overviews!
>
> Any ideas, thoughts or tips will be appreciated.

Hello Ammar,

the default for gdal_translate is no tiling, no compression, and don't 
copy overviews. So your last gdal_translate command effectively removes 
all tiling, overviews and compression. If you want to have a tiled and 
compressed file, add the '-co compress=lzw" to your first gdal_translate 
command, which will create a tiled and compressed 'out.tif'. Then add 
overviews to that with gdaladdo. If I'm not mistaken, the overviews use 
the settings from the main dataset, so would also use lzw compression.

Best,
Vincent Schut.
>
> //Ammar
>
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