The individual slices are 2048x1216, with non-interleaved color, and compressed with Unix "compress". Currently, nrrd has no "compress"-compatible encoding; the gzip and bzip2 encodings in nrrd only handle those specific compression methods. Perhaps confusingly, the similarly named command-line tools (gzip, bzip2) automatically detect and handle multiple compression types. However, we can use zcat to uncompress the data, and then pipe this to unu make.
The following sequence can be used to inspect any one of the slices with xv, avf1100a is just an example. The image viewer doesn't have to be xv; it just needs to be able to take PPM images on stdin and display them.
How this works:zcat data/avf1100a.raw.Z \ | unu make -i - -t uchar -s 2048 1216 3 -e raw \ | unu permute -p 2 0 1 \ | unu save -f pnm | xv -
In many of the following examples, an image will be saved to PNG file with ImageMagick's "convert" program, via
This last step is something it would make sense to create an alias for:... | unu save -f pnm | convert PNM:- blah.png
For example, one of the slices can be downsampled and saved to PNG as follows:alias topng "unu save -f pnm | convert PNM:- "
zcat data/avf1100a.raw.Z \ | unu make -i - -t uchar -s 2048 1216 3 -e raw \ | unu resample -k cubic:0,0.5 -s x0.2 x0.2 = \ | unu permute -p 2 0 1 | topng doc/avf1100a.th.png
Inspecting slices in this manner allows one to see that the shoulders begin around slice avf1215a:
zcat data/avf1215a.raw.Z \ | unu make -i - -t uchar -s 2048 1216 3 -e raw \ | unu resample -k cubic:0,0.5 -s x0.2 x0.2 = \ | unu permute -p 2 0 1 | topng doc/avf1215a.th.png