topic Re: Making raster file smaller without compression in Data Management Questions

Making raster file smaller without compression

DitlevReventlow — Mon, 18 May 2015 11:23:47 GMT

Hey everyone.

Is there anyway to make a raster file smaller without compressing it? It is simply a matter of disk space and processing speed.

Is this by any means possible?

Thank you.

Best regards

Ditlev Reventlow.

Re: Making raster file smaller without compression

DanPatterson_Retired — Mon, 18 May 2015 11:38:27 GMT

What format are you using? simply changing the format will help. Are using tif, Esri Grid etc. Try outputs to various formats for the same input file to compare the differences.

Re: Making raster file smaller without compression

DitlevReventlow — Mon, 18 May 2015 11:52:23 GMT

Thank you. It is a tiff file. Do you know which format has the lowest storage space?

Re: Making raster file smaller without compression

JayantaPoddar — Mon, 18 May 2015 12:05:26 GMT

Hi Ditlev,

Although I would not recommend conversion of TIFF file to any other format, but if you really need it, you could convert it to any lossless format (e.g. PNG). Keep in mind, PNG supports upto 3 bands of raster.

Re: Making raster file smaller without compression

DitlevReventlow — Mon, 18 May 2015 12:12:29 GMT

Hey Jayanta.

The problem is that I need a LUCL map but the resolution of it is not that important. Therefore I would originally use the MODIS LUCL, but as we talked about in the other thread this file could not be transformed to WGS 1984 because of its Datum. Therefore I need to use another map and this big size map is already in WGS 1984. But It is not so important that the quality of the map goes down in the process.

Re: Making raster file smaller without compression

DitlevReventlow — Mon, 18 May 2015 14:15:11 GMT

I have converted the TIFF to PNG now. However, when I go into source, it lists the format as FGDBR and the size is still the same. What could the reason be for this?

Re: Making raster file smaller without compression

NeilAyres — Mon, 18 May 2015 14:37:38 GMT

If the output is into a file geodatabase, the format is fgdb,and the filename has no extension. If you are exporting to tiff, png or anything then the output needs to be a subdirectory (not into the *.gdb), with the appropriate file extension.

If you just need a reduced resolution image which will also make the file size smaller, then try resample, or even copy raster with the new cellsize set in the environement settings.

Re: Making raster file smaller without compression

DitlevReventlow — Mon, 18 May 2015 16:41:48 GMT

Great, resampling was exactly the tool that I needed. Thanks a lot!