H2N5

H2N5 is:

• An Australian strain of avian flu
• [(E)-Hydrazinylidenehydrazinylidene]azanide
• HTTP 2 N5: A simple program to serve N5 datasets over HTTP as tiled image stacks

Minimum supported Rust version (MSRV)

Stable 1.56

Quick start

cargo install h2n5
h2n5 path/to/my.n5
curl http://127.0.0.1:8088/tile/group/dataset/0_1/512_256/1/2/3.jpg?q=80

Tile URLs are constructed as:

http://[bind_address]:[port]/tile/[n5_dataset]/[slicing_dims]/[tile_size]/[coordinates].[format]?[query parameters]

For example, the URL:

http://127.0.0.1:8088/tile/group/dataset/0_1/512_256/1/2/3.jpg?q=80

Will slice a 512 px by 256 px tile from the group/dataset dataset along axes 0 (as tile X) and 1 (as tile Y), respectively. The returned tile will start at voxel coordinates [1, 2, 3], be encoded as JPEG, with a quality of 80.

For more options, see the command line help:

h2n5 -h

Notes

• PNG (png) and JPEG (jpg|jpeg) encoding formats are supported.
• Currently, only grayscale tiles are returned (by slicing remaining dimensions as singletons) or grayscale + alpha or RGBA by packing these scalar values across channels using the pack query parameter. Slicing a third dimension for RGB(A) channels (e.g., slicing_dims as 0_1_4) will be supported, and is currently parsed correctly, but not yet implemented for tile encoding.

Supported data type, channel packing, and encoding formats

Logging

Logs are output to stderr using standard Rust log and env_logger in the actix_web scope. By default only major errors at the WARN level or above are shown. For example, to show all requests:

RUST_LOG=actix_web=info h2n5

For more information, see the env_logger and actix_web logging middleware documentation.

License

Licensed under either of

• Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.