Read Meta Raster Format Files (e.g. .mrf, .idx, .data)
npm install mrfbash
npm install mrf
`Usage
loading the library
You can load the library in three different ways.
$3
If you are using CommonJS, you can require the library like so:
js
const mrf = require("mrf");
`
Or import a specific function like so:
js
const { parseIDX } = require("mrf");
`
$3
If you are using ES6 Modules, you can import like so:
js
import mrf from 'mrf';
`
Or import a specific function like so:
js
import { parseIDX } from "mrf";
`
$3
html
`parsing .mrf files
The .mrf file includes the metadata about your project. You can parse it by calling parseMRF, as in the example below:
js
import { readFileSync } from 'fs';
import { parseMRF } from 'mrf';const buffer = readFileSync("./example.mrf");
const result = parseMRF(buffer);
`
result is a JSON serializable object that looks like the following:
javascript
{
"area": 50362506,
"height": 7587,
"width": 6638,
"depth": 1,
"numBands": 4,
"pageHeight": 512,
"pageWidth": 512,
"pageDepth": 1,
"pageBands": 1,
"compression": "LERC",
"rsets": {
"model": "uniform",
"scale": 2
},
"xmin": 601135,
"ymin": 3422859,
"xmax": 607773,
"ymax": 3430446,
"projection": "PROJCS[\"NAD83 / UTM zone 16N\",GEOGCS[...]]",
"order": "band",
"overviews": [
{
"height": 3794,
"heightInPages": 8,
"pages": 224,
"offset": 780,
"width": 3319,
"widthInPages": 7,
"scale": {
"height": 1.999736425935688,
"width": 2
}
},
/*
.
.
.
*/
]
}
`
There are other properties available that deal with time and build options. Please see the examples.parsing .idx files
Index files list the offset and length of each tile in binary format. You can parse this information like so:
javascript
import { readFileSync } from 'fs';
import { parseIDX } from 'mrf';const buffer = readFileSync("test.idx");
const result = parseIDX(buffer);
`
result is an array of objects that looks like the following:
js
[
{ "offset": 0, "length": 181646 },
{ "offset": 35326744, "length": 178797 },
{ "offset": 70080116, "length": 171538 },
// 1085 more items
]
``