@thi.ng/pixel-io-geotiff/read.js

GeoTIFF reader support for @thi.ng/pixel

import { typedArrayType } from "@thi.ng/api";
import { FLOAT_GRAY_RANGE, floatBuffer } from "@thi.ng/pixel";
import { Pool, fromArrayBuffer } from "geotiff";
const readGeoTiff = async (src, opts = {}) => {
  const tiff = await fromArrayBuffer(src.buffer);
  const tiffImg = await tiff.getImage();
  const width = tiffImg.getWidth();
  const height = tiffImg.getHeight();
  const pool = opts.pool instanceof Pool ? opts.pool : opts.pool ? new Pool() : void 0;
  const data = (await tiffImg.readRasters({ pool, samples: [opts.channel || 0] }))[0];
  const type = typedArrayType(data);
  const [min, max] = opts.range ? opts.range : data.reduce(
    (acc, x) => {
      acc[0] = Math.min(acc[0], x);
      acc[1] = Math.max(acc[1], x);
      return acc;
    },
    [Infinity, -Infinity]
  );
  const fmt = FLOAT_GRAY_RANGE(min, max);
  let img;
  switch (type) {
    case "i8":
    case "u8":
    case "i16":
    case "u16":
    case "i32":
    case "u32":
      img = floatBuffer(width, height, fmt, new Float32Array(data));
      break;
    case "f32":
      img = floatBuffer(width, height, fmt, data);
      break;
    case "f64":
      img = floatBuffer(width, height, fmt, new Float32Array(data));
      break;
  }
  return { img, tiff: tiffImg };
};
export {
  readGeoTiff
};