Question: Original band data types

[Nightsphere]

Hello, it's once again question time! I would like to be able to display the raster's original data types for each band for users. For example, being able to know for sure that in band X, number A is an integer and number B is floating point. JavaScript converts everything to number, which I'm sure you know, and it doesn't help if the original data type was uint16, float32, etc.

Is there a way to determine this already in the georaster object somewhere that I've missed?

[DanielJDufour]

Hi, @Nightsphere . This is a great question. I don't have a great answer. The current version of georaster doesn't technically support it, but I'll make sure the next version does (I'm actively working on it).

In the interim, there are two ways to get the information: 1) For georasters that you load via url you can do:

// inside an async function
const geotiff = georaster._geotiff;
const image = await geotiff.getImage();
const bitsPerSample = image.fileDirectory.BitsPerSample;
// bitsPerSample is [16]

2) For georasters that have been loaded by a file or array buffer, you will have to use the geotiff-js library to get at the values and can do something like this:

import { fromArrayBuffer } from 'geotiff';

// inside async function
const geotiff = await fromArrayBuffer(arrayBuffer);
const image = await geotiff.getImage();
const bitsPerSample = image.fileDirectory.BitsPerSample;
// bitsPerSample is [16]

However, I can't guarantee that the next major version of georaster will support georaster._geotiff, so use with caution.

Thanks for bringing this up and let's keep this issue open, so I can track it and include this info in the next version of georaster.

[Nightsphere]

Awesome, thank you for the quick response as always. We are using georasters from a file and were already looking into geotiff-js, so it's good to hear it was the right direction.

It's also great to hear another version is being worked on! Looking forward to it.