LERC

File Format
Name	LERC
Ontology	Electronic File Formats Graphics LERC ; ; ;
Extension(s)	.lrc
Released	2010 (Lerc1), 2014 (Lerc2)

LERC (Limited Error Raster Compression), also written Lerc, is a format for compressed raster image data. It was developed by Esri.

It may appear in a file by itself, or as part of MRF format, or be used as a compression method in a format such as GeoTIFF.

There are two major versions, known as "Lerc1" and "Lerc2".

Identifiers

The OptimizeRasters project[1] suggests that the usual filename extension is .lrc.

Lerc2: Files start with ASCII "Lerc2 " (note trailing space).

Lerc1: More research needed. Some files start with "CntZImage ".