COPC

!test

A TypeScript library for reading and parsing COPC data.

npm install copc

Usage

$3

``typescript
// Can also pass a getter instead of a filename string.
const copc = await Copc.create(filename)
console.log(copc)
`
`
{
header: {
fileSignature: 'LASF',
fileSourceId: 0,
globalEncoding: 16,
projectId: '00000000-0000-0000-0000000000000000',
majorVersion: 1,
minorVersion: 4,
systemIdentifier: '',
generatingSoftware: '',
fileCreationDayOfYear: 1,
fileCreationYear: 1,
headerLength: 375,
pointDataOffset: 1424,
vlrCount: 3,
pointDataRecordFormat: 7,
pointDataRecordLength: 36,
pointCount: 100000,
pointCountByReturn: [
50002, 49998, 0, 0,
0, 0, 0, 0,
0, 0, 0, 0,
0, 0, 0
],
scale: [ 0.01, 0.01, 0.01 ],
offset: [ -8242596, 4966606, 0 ],
min: [ -8242746, 4966506, -50 ],
max: [ -8242446, 4966706, 50 ],
waveformDataOffset: 0,
evlrOffset: 630520,
evlrCount: 1
},
vlrs: [
{
userId: 'copc',
recordId: 1,
contentOffset: 429,
contentLength: 160,
description: 'COPC info VLR',
isExtended: false
},
{
userId: 'laszip encoded',
recordId: 22204,
contentOffset: 643,
contentLength: 46,
description: 'lazperf variant',
isExtended: false
},
{
userId: 'LASF_Projection',
recordId: 2112,
contentOffset: 743,
contentLength: 681,
description: '',
isExtended: false
},
{
userId: 'copc',
recordId: 1000,
contentOffset: 630580,
contentLength: 160,
description: 'COPC Hierarchy',
isExtended: true
}
],
info: {
cube: [ -8242746, 4966506, -50, -8242446, 4966806, 250 ],
spacing: 2.34375,
rootHierarchyPage: { pageOffset: 630580, pageLength: 160 },
gpsTimeRange: [ 42, 42 ]
},
wkt: 'PROJCS["WGS 84 / Pseudo-Mercator",GEOGCS["WGS 84",DATUM["WGS_1984",SPHEROID["WGS 84",6378137,298.257223563,AUTHORITY["EPSG","7030"]],AUTHORITY["EPSG","6326"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4326"]],PROJECTION["Mercator_1SP"],PARAMETER["central_meridian",0],PARAMETER["scale_factor",1],PARAMETER["false_easting",0],PARAMETER["false_northing",0],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Easting",EAST],AXIS["Northing",NORTH],EXTENSION["PROJ4","+proj=merc +a=6378137 +b=6378137 +lat_ts=0 +lon_0=0 +x_0=0 +y_0=0 +k=1 +units=m +nadgrids=@null +wktext +no_defs"],AUTHORITY["EPSG","3857"]]',
eb: []
}
`

$3

`typescript
const { nodes, pages } = await Copc.loadHierarchyPage(
filename,
copc.info.rootHierarchyPage
)
const root = nodes['0-0-0-0']!
const view = await Copc.loadPointDataView(filename, copc, root)
console.log('Dimensions:', view.dimensions)

const getters = ['X', 'Y', 'Z', 'Intensity'].map(view.getter)
function getXyzi(index: number) {
return getters.map(get => get(index))
}
const point = getXyzi(0)
console.log('Point:', point)
`
`
Dimensions: {
X: { type: 'float', size: 8 },
Y: { type: 'float', size: 8 },
Z: { type: 'float', size: 8 },
Intensity: { type: 'unsigned', size: 2 },
ReturnNumber: { type: 'unsigned', size: 1 },
NumberOfReturns: { type: 'unsigned', size: 1 },
Synthetic: { type: 'unsigned', size: 1 },
KeyPoint: { type: 'unsigned', size: 1 },
Withheld: { type: 'unsigned', size: 1 },
Overlap: { type: 'unsigned', size: 1 },
ScannerChannel: { type: 'unsigned', size: 1 },
ScanDirectionFlag: { type: 'unsigned', size: 1 },
EdgeOfFlightLine: { type: 'unsigned', size: 1 },
Classification: { type: 'unsigned', size: 1 },
UserData: { type: 'unsigned', size: 1 },
ScanAngle: { type: 'float', size: 4 },
PointSourceId: { type: 'unsigned', size: 2 },
GpsTime: { type: 'float', size: 8 },
Red: { type: 'unsigned', size: 2 },
Green: { type: 'unsigned', size: 2 },
Blue: { type: 'unsigned', size: 2 }
}
Point: [-8242596, 4966706, 50, 128]
``