ad-plugins

NDPlugin implementations for areaDetector-rs. 23 image processing and data handling plugins for real-time detector data pipelines.

No C dependencies. Pure Rust with real encoding libraries (JPEG, TIFF, LZ4, FFT).

Plugins

Statistical Analysis

Plugin	Description
NDStats	Min/max/mean/sigma/total, centroid with threshold, histogram, row/column profiles, higher-order moments
NDROIStat	Multi-ROI statistics with background subtraction and time series
NDAttrPlot	Circular buffer tracking of numeric NDArray attributes
NDAttribute	Single attribute extraction with cumulative sum

Image Transformation

Plugin	Description
NDROIPlugin	Region-of-interest extraction with auto-center (CoM/Peak), binning, per-dimension enable
NDTransform	8 geometric transforms: rotations (90/180/270), flips (H/V/diagonal)
NDColorConvert	RGB/Mono conversion, Bayer demosaic (bilinear), false-color jet LUT
NDOverlay	Draw shapes (cross, rectangle, ellipse, text) with 5x7 bitmap font

Array Processing

Plugin	Description
NDProcess	4-tap recursive filter, background/flatfield save, offset/scale, clipping
NDFFT	1D (rows) and 2D (separable) FFT via rustfft, DC suppression, frame averaging

Data Buffering

Plugin	Description
NDCircularBuff	Pre/post-trigger ring buffer with Calc expression evaluator
NDTimeSeries	OneShot/RingBuffer accumulation for statistics channels
NDStdArrays	Latest array storage (passthrough with caching)

File I/O

Plugin	Description
NDFileHDF5	HDF5 file writer (feature-gated `hdf5` crate, with binary fallback)
NDFileJPEG	JPEG encoding/decoding via jpeg-encoder/jpeg-decoder
NDFileTIFF	TIFF encoding/decoding via tiff crate

Codec

Plugin	Description
NDCodec	Lossless compression: LZ4 (lz4_flex) + JPEG, preserves original data type

Position & Pixel Correction

Plugin	Description
NDPos	Attach position metadata from JSON list (Discard/Keep modes)
NDBadPixel	Bad pixel correction: Set (fixed value), Replace (neighbor), Median (kernel). JSON config

Multiplexing

Plugin	Description
NDGather	Passthrough multiplexer (many → one)
NDScatter	Round-robin splitter (one → many)
Passthrough	No-op stub for unimplemented plugin types

Features

[features]
default = ["parallel"]
parallel = ["rayon"]    # Rayon data-parallelism for CPU-heavy plugins
hdf5 = ["dep:hdf5-metno"]  # HDF5 file format (built from bundled source, requires cmake)
ioc  = ["ad-core/ioc"]  # IOC startup commands (NDStatsConfigure, etc.)

Parallel Processing

The parallel feature (enabled by default) uses rayon to parallelize CPU-heavy image processing in 4 plugins:

Plugin	Parallelized Operations
NDROIStat	Per-ROI stats computation (`par_iter` over ROI regions)
NDStats	Basic stats (fold+reduce), centroid (fold+reduce), histogram (par_chunks + merge)
NDColorConvert	Bayer demosaic (`bayer_to_rgb1` row-parallel)
NDProcess	Stages 1–4: background, flat field, offset/scale, clipping (element-wise `par_iter_mut`)

Not parallelized: FFT (rustfft internal SIMD), recursive filter (IIR dependency chain), profiles (memory access pattern), Overlay/Transform (lightweight).

Thread pool management:

All plugins share a single rayon ThreadPool to avoid over-subscription when multiple plugins process data concurrently. The pool is sized to available_cores - 2 (minimum 1), reserving headroom for port driver data threads, autoconnect tasks, and the tokio runtime.

To override the thread count, call set_num_threads() before the first array is processed:

ad_plugins::par_util::set_num_threads(4);

A minimum element threshold (PAR_THRESHOLD = 4096) prevents rayon overhead from dominating on small arrays. Below this threshold, the sequential path is used automatically.

To disable parallelism entirely:

ad-plugins = { version = "0.2", default-features = false }

Usage

Each plugin implements NDPluginProcess:

use ad_plugins::stats::NDStatsPlugin;
use ad_core::plugin::NDPluginProcess;

let mut stats = NDStatsPlugin::new();
let result = stats.process_array(&array, &pool);
// result.arrays contains processed output

With the ioc feature, plugins register as st.cmd startup commands:

# In st.cmd
NDStatsConfigure("STATS1", 5, "SIM1")
NDROIConfigure("ROI1", 5, "SIM1")
NDStdArraysConfigure("IMAGE1", 5, "SIM1")

Build

cargo build -p ad-plugins                    # plugins only
cargo build -p ad-plugins --features ioc     # with IOC commands
cargo build -p ad-plugins --features hdf5    # with HDF5 support
cargo test -p ad-plugins                     # 205 tests

License

MIT

ad-plugins 0.4.0