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 1.39

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

| | gray (default) | graya | rgba | |--------|----------------|------------|------------| | UINT8 | JPEG PNG | | | | UINT16 | PNG | JPEG PNG | | | UINT32 | | PNG | JPEG PNG | | UINT64 | | | PNG | | FLOAT32| | PNG | JPEG PNG | | FLOAT64| | | PNG |

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.