[gdal-dev] Just want to do simple batch compression...

[srygonic]

I have a lot of geotiffs which are quite large at times (meaning they have
quite a bit of unnecessary white space between) and I would like to run a
batch script to just do a simple compression on them as I believe that they
are not compressed because the files that just contain a lot of white space
are still unnecessarily huge.

I've been trying for quite a bit (totally new to GDAL) and reading around.
But I can't seem to produce any usable results. Most of the time my image
turns totally black (when opened in QGIS).

I've read that the images just needs to scale up but I'm either getting
thrown with 16 bit errors or still produces a black image.

I've been trying to piece together some commands via
http://www.gdal.org/frmt_gtiff.html and other blogs / discussion forums
online but I'm not too sure I'm heading in the right direction. As
mentioned... This is all pretty new to me. Just starting looking into GDAL
48 hours ago.

Below are the commands that I've tried. I'm using OSGeo4W Shell command line
to run this.

cd /d e:
cd E:\TIFFs_Test
gdal_translate GTIFF_RAW:GAPS_2017-02-23.tif test.tif -co PHOTOMETRIC=CMYK
-co TFW=YES -co TILED=YES -co BIGTIFF=IF_SAFER -co COMPRESS=JPEG

gdal_translate GTIFF_RAW:GAPS_2017-02-23.tif test1.tif -co PHOTOMETRIC=CMYK
-co TFW=YES -co TILED=YES -co BIGTIFF=IF_SAFER -co COMPRESS=JPEG -a_srs
EPSG:3414

gdal_translate GTIFF_RAW:GAPS_2017-02-23.tif test2.tif -co PHOTOMETRIC=YCBCR
-co TFW=YES -co TILED=YES -co BIGTIFF=IF_SAFER -co COMPRESS=JPEG -a_srs
EPSG:3414

gdal_translate GTIFF_RAW:GAPS_2017-02-23.tif test4.tif -co PHOTOMETRIC=YCBCR
-co TFW=YES -co TILED=YES -co BIGTIFF=IF_SAFER -co COMPRESS=JPEG -ot Int16
-scale 0 255 0 32767

gdal_translate GTIFF_RAW:GAPS_2017-02-23.tif test6.tif -co PHOTOMETRIC=YCBCR
-co TFW=YES -co TILED=YES -co BIGTIFF=IF_SAFER -co COMPRESS=JPEG -scale 0
255 0 32767

The image in question is uploaded here.
https://www.dropbox.com/s/vol0bflu5avw7xp/TIFFs_Test.rar?dl=0

The file is about 444MB but can be compress via zip to about 81MB. So there
is obviously still room for compression. Can anybody point me in the right
direction on how to go about this? I would like to eventually run a batch
script on a folder to auto compress all the TIFF files.



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Sent from: http://osgeo-org.1560.x6.nabble.com/GDAL-Dev-f3742093.html