Extracting an image chunk from a collection of Large MrSid Images
[This article was first published on dylan's blog, and kindly contributed to R-bloggers]. (You can report issue about the content on this page here)
Want to share your content on R-bloggers? click here if you have a blog, or here if you don't.
Want to share your content on R-bloggers? click here if you have a blog, or here if you don't.
Recently needed to extract a small “chunk” from a collection of adjacent MrSid mosaics, each about 4Gb in size. Once again, GDAL came to the rescue, and saved much time and agony wile working with very large, compressed, and proprietary-format files. Two lessons learned:
- The GDAL VRT format can save a lot of time and effort by providing access to a collection of files without actually altering the originals.
- ArcGIS 9.x does not like BigTIFF files. When file sizes approach or exceed 4Gb, the HFA format is a nice alternative.
Have patience, subsetting a chunk out of 5 adjacent MrSid files (4Gb each) took about 7 hours. Fun experiment: extract sub-chunks from each of the constituent sid files and distribute across CPU cores.
To leave a comment for the author, please follow the link and comment on their blog: dylan's blog.
R-bloggers.com offers daily e-mail updates about R news and tutorials about learning R and many other topics. Click here if you're looking to post or find an R/data-science job.
Want to share your content on R-bloggers? click here if you have a blog, or here if you don't.