rle
v1.0.2
Published
RLE - run length encoding, the simplest approach for lossless compression
Downloads
335
Maintainers
Readme
##RLE - Run Length Encoding the simplest approach for lossless compression
###Install
npm install rle
###API
Uint32Array RLE.encode(Array<*> stream)
Encodes the given stream of binary data by run length. Each "truthy" element in the stream is treated as 1.
The maximum run length is "limited" to 2^28.
This function further packs the data to reduce the memory usage by nominal 1/4 of the simple RLE approach.
Array<boolean> RLE.decode(Uint32Array stream)
Decodes the stream of RLE data to a binary stream.
Array<number> RLE.encodeSimple(Array<*> stream)
Encodes the given data by run length using the simple approach. Each "truthy" element in the stream is treated as 1.
The return value represents a stream of alternating run lengths starting with the length of 0.
Array<boolean> RLE.decodeSimple(Array<number> stream)
Decodes the stream of simple RLE data to a binary stream.
###Example
var rle = require('rle');
var blackAndWhite = getBlackAndWhiteData();
var encoded = rle.encode(blackAndWhite.asArray());
//....
var decoded = rle.decode(encoded);
####Base64
var rleEncoded = rle.encode(data);
base64Encoded = new Buffer(new Uint8Array(rleEncoded.buffer)).toString('base64');
//....
var base64Decoded = new Uint32Array(new Uint8Array(new Buffer(base64Encoded, 'base64')).buffer);
var rleDecoded = rle.decode(base64Decoded);