coco-maskapi

An unofficial TypeScript port of Coco API's maskApi.c (reference).

Context

Coco API uses a modified version of Run Length Encoding (RLE) to efficiently store image masks. RLE data is further compressed via a modified version of LEB128 (which can be inuitively considered LEB32).

coco-maskapi aims to bring this flavor of mask compression/encoding to web browsers, favoring Canvas ImageData as the data source and target.

maskApi.c Support Parity Status

Function	Status
rleEncode	🧑‍🏭 WIP
rleDecode	🧑‍🏭 WIP
rleMerge	🗒️ TODO
rleArea	🗒️ TODO
rleNMS	🗒️ TODO (?)
bbIou	🗒️ TODO
bbNms	🗒️ TODO (?)
rleToBbox	🗒️ TODO
rleFrBbox	🗒️ TODO
uintCompare	🗒️ TODO
rleFrPoly	🗒️ TODO
rleToString	🧑‍🏭 WIP
rleFrString	🧑‍🏭 WIP

Development

pnpm install
pnpm dev

Endpoints

• /, base example
• /worst, worst case experimentation