[GIS] How to decrease GeoTIFF file size by eliminating or negating the blackfill

gdalgeotiff-tiff

I have a 5 band, 16-bit orthorectified GeoTIFF from a satellite image that contains a significant amount of blackfill and has a file size of over 21GB. I would like to decrease the file size by eliminating or negating the blackfill. I have attempted to use the SPARSE_OK option in GDAL as such:

gdal_translate -of GTiff -co "BIGTIFF=YES" -co "SPARSE_OK=TRUE" -co "TILED=YES" input.tif output.tif

This has had no effect on the file size. Is my understanding of how SPARSE_OK works incorrect or is there a potential problem with the SPARSE_OK option? Is there a better way of reducing the file size? I have tried "COMPRESS=DEFLATE", which works, but then the product is veryyyy slow is loading into the viewing software.

Best Answer

COMPRESS=LZW should give you better load times and equivalent packing ratio as DEFLATE. See if that helps?

Related Solutions

[GIS] ISIS to GDAL to QGIS: Georeferencing Mars Images

Make a custom CRS using the following parameter string:

+proj=longlat +a=3396190 +b=3396190 +no_defs

You might call this CRS (say) "Mars_Geo". Then load the *.cub raster, set the project CRS to "Mars_geo" and enable on-the-fly CRS transformation. Doing this will distort the raster to some extent but you will get lon/lat coordinates reported as you move the pointer around the screen.

When checking the corner coordinates of the raster bear in mind that the corners are not the corners of the data. The image is an upright rectangle having the extents shown in the attached image.

Please bear in mind that I know nothing about Mars and next to nothing about Sinusoidal CRSs, so be careful!

enter image description here

[GIS] How to calculate pixel size in GeoTIFF

That your numbers differ are because of different precisions. Your pixel size has 15 decimals. Your calculation uses a bounding box with 3 decimals.

Just two sidenotes on the topic:

You can´t calculate the pixel size to the accuracy you may be hoping for. You have different length distortions depending on the location. In UTM zones this reaches up to 0,1% at the borders to the next zone. And your difference is at the 8th decimal... Also there are deviations from rotation and scaling.

That means that you do not have an exact pixel size anyway. Of course when you create a raster you set a size like exact 30m. But that also differs whenever you transform it or cut something from it. There it depends on your transformation and interpolation when the new raster is created. Its no excact science to such (unnecessary) precisions.

Best Answer

Related Solutions

[GIS] ISIS to GDAL to QGIS: Georeferencing Mars Images

[GIS] How to calculate pixel size in GeoTIFF

Related Question