OSAscript to output the footprint of what's visible in the current Google Earth Pro window as a geojson file

google-earth-perspective-to-geojson.js

#!/usr/bin/env osascript -l JavaScript

// usage: google-earth-perspective-to-geojson.js xSamples ySamples > currentPerspective.geojson

function run(argv) {
  var xSamples = argv[0] || 50;
  var ySamples = argv[1] || 50;

  var ge = Application('Google Earth Pro');

  var points = [];

  // kinda dumb but keeps things in correct order for geojson
  for (var x=0; x<xSamples; x++) {
    var xn = normalize(x, xSamples);
    var loc = ge.getpointonterrain([ xn, -1]);
    points.push([loc[1],loc[0]])
  }

  for (var y=0; y<ySamples; y++) {
    var yn = normalize(y, ySamples);
    var loc = ge.getpointonterrain([ 1, yn]);
    points.push([loc[1],loc[0]])
  }

  for (var x=xSamples; x>0; x--) {
    var xn = normalize(x, xSamples);
    var loc = ge.getpointonterrain([ xn, 1]);
    points.push([loc[1],loc[0]])
  }

  for (var y=xSamples; y>0; y--) {
    var yn = normalize(y, ySamples);
    var loc = ge.getpointonterrain([ -1, yn]);
    points.push([loc[1],loc[0]])
  }

  points.push(points[0]); // last point has to be same as first

  var output = {
    "type": "FeatureCollection",
    "features": [
      {
        "type": "Feature",
        "properties": {},
        "geometry": {
          "type": "Polygon",
          "coordinates": []
        }
      }
    ]
  };

  output.features[0].geometry.coordinates[0]=points;

  return JSON.stringify(output);
}

function normalize(n,outOf) {
  return (n/(outOf-1))*2-1;
}

coords default to 0,0 at infinity; could implement a scan to find horizon line when that happens

Use with rio clip input.tif output.tif --bounds $(fio info currentPerspective.json --bounds) to crop a raster to the smallest size that will cover the current perspective.

You can then convert that to a KML overlay with gdal_translate -of KMLSUPEROVERLAY input.tif output.kmz -co FORMAT=JPEG