Module coco 

COCO Dataset Format Support

This module provides comprehensive support for the COCO (Common Objects in Context) dataset format, enabling bidirectional conversion between COCO and EdgeFirst formats.

Supported Workflows

1. COCO → EdgeFirst Arrow: Convert COCO JSON/ZIP to Arrow-based EdgeFirst format
2. EdgeFirst Arrow → COCO: Convert Arrow format back to COCO JSON
3. COCO → Studio: Import COCO directly into EdgeFirst Studio via API
4. Studio → COCO: Export Studio dataset to COCO format

Scope

Phase 1 supports:

• Bounding boxes (box2d)
• Polygon segmentation (mask)
• RLE segmentation (decoded to polygons)

Not yet supported: keypoints, captions, panoptic segmentation.

Example

use edgefirst_client::coco::{CocoReader, CocoToArrowOptions, coco_to_arrow};

// Read COCO annotations
let reader = CocoReader::new();
let dataset = reader.read_json("annotations/instances_val2017.json")?;
println!(
    "Found {} images and {} annotations",
    dataset.images.len(),
    dataset.annotations.len()
);

// Convert to EdgeFirst Arrow format
let options = CocoToArrowOptions::default();
let count = coco_to_arrow(
    "annotations/instances_val2017.json",
    "dataset.arrow",
    &options,
    None,
)
.await?;
println!("Converted {} samples", count);

Re-exports

pub use studio::CocoExportOptions;

pub use studio::CocoImportOptions;

pub use studio::CocoImportResult;

pub use studio::CocoUpdateOptions;

pub use studio::CocoUpdateResult;

pub use studio::CocoVerifyOptions;

pub use studio::export_studio_to_coco;

pub use studio::import_coco_to_studio;

pub use studio::update_coco_annotations;

pub use studio::verify_coco_import;

pub use verify::BboxValidationResult;

pub use verify::CategoryValidationResult;

pub use verify::MaskValidationResult;

pub use verify::VerificationResult;

Modules

studio

COCO import/export for EdgeFirst Studio.

verify

COCO dataset verification utilities.

Structs

ArrowToCocoOptions

Options for Arrow to COCO conversion.

CocoAnnotation

Annotation for object detection and instance segmentation.

CocoCategory

Category definition.

CocoCompressedRle

Compressed RLE segmentation (LEB128 encoded).

CocoDataset

Top-level COCO dataset structure.

CocoImage

Image metadata.

CocoIndex

Lookup tables for efficient COCO data access.

CocoInfo

Dataset metadata.

CocoLicense

License information.

CocoReadOptions

Options for COCO reading.

CocoReader

Streaming COCO reader for large datasets.

CocoRle

Uncompressed RLE (Run-Length Encoding) segmentation.

CocoToArrowOptions

Options for COCO to Arrow conversion.

CocoWriteOptions

Options for COCO writing.

CocoWriter

COCO writer for generating JSON and ZIP files.

Enums

CocoSegmentation

Segmentation format: polygon array or RLE.

Functions

arrow_to_coco

Convert EdgeFirst Arrow format to COCO annotations.

box2d_to_coco_bbox

Convert EdgeFirst Box2d to COCO bbox [x, y, w, h] (top-left, pixels).

calculate_coco_area

Calculate area from COCO segmentation (in pixels²).

coco_bbox_to_box2d

Convert COCO bbox [x, y, w, h] (top-left, pixels) to EdgeFirst Box2d (top-left, normalized).

coco_polygon_to_mask

Convert COCO polygon segmentation to EdgeFirst Mask format.

coco_rle_to_mask

Convert RLE segmentation to EdgeFirst Mask.

coco_segmentation_to_mask

Convert any COCO segmentation to EdgeFirst Mask.

coco_to_arrow

Convert COCO annotations to EdgeFirst Arrow format.

decode_compressed_rle

Decode compressed RLE (LEB128) to binary mask.

decode_rle

Decode uncompressed RLE to binary mask.

infer_group_from_filename

Infer group name from COCO annotation filename.

infer_group_from_folder

Infer the group name from an image folder path.

mask_to_coco_polygon

Convert EdgeFirst Mask format to COCO polygon segmentation.

mask_to_contours

Convert binary mask to polygon contours.

read_coco_directory

Read all COCO annotation files from a directory.

validate_coco_bbox

Validate that a COCO bounding box is within image bounds.