Dear all, I have been looking for a possibility to compress some pretty large files using IDL code with envi functionality. The original images are around 24GB in size, long integer arrays, dimensions ~ 22000x28000x9. I came across the option of using gzip compression for envi files using the envi_write_envi_file function. This first gave me very promising results when I wrote not so large files, e.g. 8000x9000x1 byte images that were originally ~60MB had a compressed size of 800KB! I can open them without problems in envi... However, once I tried writing compressed outputs for those very big files, I get errors once I try to display it in envi. It seems to write fine and also allows me to open it as it appears in the available bands list. But once I try to display the data i get an end of file error .."end of file encountered".. [see screenshot below] My question is: are there any restrictions regarding filesize or file dimensions when using the gzip compression for envi files? The information given in the envi help on the compression is pretty limited so any additional information would be really helpful... Thanks in advance, Patrick