Movies in this entry were compressed by EMPIAR Japan to save space and bandwidth.
The compression is lossless in that all pixel intensities remain exactly the same after decompression.
However, some metadata in the MRC header were lost.
The original files before compression are available from EMPIAR EBI.

data/2023*.mrc:
  Compression was carried out by separating (“un-normalizing”) the gain.
  The details of the method are described in
  https://relion.readthedocs.io/en/release-3.1/Reference/MovieCompression.html#gain-normalised-movies.
  
  Please apply the gain reference (gain-reference.mrc) during processing.

data/2024*.mrc:
  Although the original movies are in float32 MRC, the pixel values are integers and
  apparently gain non-normalized. They were compressed by BZIP2 as is.
  Do NOT apply `gain-reference.mrc` above.

  Some programs (e.g. RELION >= 4.0.1 and CryoSPARC) can process compressed movies without explicit
  decompression. For other programs, movies have to be decompressed beforehand. In this case,
  you might want to convert decompressed MRC movies into TIFF to save your local storage.

Original size:   3,912,927,528 kilobytes
Compressed size:   383,622,320 kilobytes