@weacast/gtiff2json


A command line utility that decodes GeoTIFF files as JSON.

This utility uses the native GDAL binding for Node.js : node-gdal.

This work is highly inspired from geotiff2json but extends it to support:
* simple JSON conversion without RLE encoding
* any block size in TIFF files (not just squares)

Installation

``
npm install -g @weacast/gtiff2json
`

Usage

$3

The gtiff2json CLI can be used similarly from the native OS CLI or from Node.

`
> grib2json --help (or node bin.js --help)
Usage: grib2json (or node bin.js) [options]
-V, --version output the version number
-c, --compress Output RLE compressed JSON
-r, --round Round values to nearest integer when performing RLE compression
-p, --precision Limit precision in JSON using the given number of digits after the decimal point (default: -1)
-o, --output Output in a file instead of stdout
-v, --verbose Verbose mode for debug purpose
-h, --help output usage information
`

$3

Here's an example that converts file.tif into a JSON array and writes it to disk as data.json:

`javascript
const geotiff2json = require('@weacast/gtiff2json')
const fs = require('fs')

geotiff2json('file.tif').then(function(data) {
fs.writeFile('data.json', JSON.stringify(data), function(err) {
if(err) {
console.error('Oh no, writing failed!', err)
return
}
})
})
`

Here's an example that converts file.tif into an RLE value array and writes it to disk as data.json:

`javascript
const geotiff2json = require('@weacast/gtiff2json')
const fs = require('fs')

geotiff2json('file.tif', true).then(function(data) {
fs.writeFile('data.json', JSON.stringify(data), function(err) {
if(err) {
console.error('Oh no, writing failed!', err)
return
}
console.log('wrote ' + (data.length / 2) + ' tuples into file.')
})
`

The output file's content will look similar to this:

`json
[
100,10,
132,1,
80,5,
...
]
`
Note: The linebreaks and whitespace have been added for better readability, the file won't contain those to reduce size.

These values are in fact value pairs.
* The first value of each pair is the y-coordinate of the point.
* The second value of each pair is the number of times this y-coordinate is repeated.

So in the example above, the y-value 100 shall be repeated 10 times, the y-value 132` shall be repeated once and so on..

Contribute

If you find a bug or a problem or data that doesn't parse correctly, even though it should, please report an issue here.

In case you found a GeoTIFF that doesn't parse correctly, please attach a link to the file or attach it to the issue directly.

If you have improvement suggestions, feel free to fork this repository and submit a pull request.

Thank you for your help and support.