commit

modules/saul-core.js

@@ -200,14 +200,14 @@ async function compareZ(options) {
  * @param {object} options.terrain - GeoTIFF object from getTerrainGeoTIFF() output
  * @returns {array} Array with world coordinates (indexes 0 and 1) and elevation (index 2). Coordinates are EPSG:25832 format.
  */
-async function getWorldXYZ(options) {
+async function getWorldXYZ(options, precision = 0.3) {
 
   const best_world_xyz = compareZ({
     image: options.image,
     terrain: options.terrain,
     xy: options.xy,
     z: 0,
-    limit: 0.5,
+    limit: precision,
     iteration: 1
   })
 

modules/saul-elevation.js

@@ -30,12 +30,14 @@ function getTerrainGeoTIFF(stac_item, auth, fidelity = 0.05) {
   })
 }
 
+/** Converts raw GeoTIFF arrayBuffer to image */
 async function consumeGeoTIFF(raw_data) {
   const tiff = await fromArrayBuffer(raw_data)
   const image = await tiff.getImage()
   return image
 }
 
+/** Constrain coordinates to be within a bounding box */
 function constrainToBbox(bbox, x, y) {
   let new_x = x
   let new_y = y

test/saul-elevation.test.js

@@ -9,7 +9,7 @@ import { getZ, getWorldXYZ, world2image } from '../modules/saul-core.js'
 
 // Vars
 const stac_item = '2021_83_29_2_0019_00003995'
-const fidelity = 0.05 // Higher number means more points and better precision
+const fidelity = 0.03 // Higher number means more points and better precision
 const max_deviation = 0.5
 
 // STAC API endpoint
@@ -53,10 +53,10 @@ function testGetWorldXYZAnumberOfTimes(item, terrain, times) {
       image: item,
       terrain: terrain
     }).then(world_xy => {
-      compareElevations(world_xy[0], world_xy[1], terrain) // lower left corner of image
+      compareElevations(world_xy[0], world_xy[1], terrain)
       const image_coords = world2image(item, world_xy[0], world_xy[1], world_xy[2])
-      assert(is_equalIsh(image_coords[0], xy[0], 0.75), `Image x coordinates ${image_coords[0]} / ${xy[0]} do not match`)
-      assert(is_equalIsh(image_coords[1], xy[1], 0.75), `Image y coordinates ${image_coords[1]} / ${xy[1]} do not match`)
+      assert(is_equalIsh(image_coords[0], xy[0], 2), `Image x coordinates ${image_coords[0]} / ${xy[0]} do not match`)
+      assert(is_equalIsh(image_coords[1], xy[1], 2), `Image y coordinates ${image_coords[1]} / ${xy[1]} do not match`)
       console.log('getWorldXYZ => world2image OK')
     })
   }
@@ -67,7 +67,7 @@ function compareElevations(x,y,geotiff) {
   .then(elevation => {
     getZ(x, y, auth)
     .then(getz_e => {
-      assert(is_equalIsh(getz_e, elevation), `Elevations ${elevation} / ${getz_e} at ${x} ${y} do not match`)
+      assert(is_equalIsh(getz_e, elevation, 0.5), `Elevations ${elevation} / ${getz_e} at ${x} ${y} do not match`)
       console.log(`Elevation at ${ x } ${ y } with delta ${Math.abs(elevation - getz_e).toFixed(2)} OK`)
     })
   })