Elevation return using ctb-info -e

i use cesium terrain builder to convert my height geotiff file to the terrain files.
The elevation range is 20-600 meters.
When i use ctb-info -e ,the number are large like 5445 5201 ...

Is that normal? or i should should be getting numbers between 20-600.


That looks correct. Per the definition of the “heightmap” terrain format at https://cesiumjs.org/data-and-assets/terrain/formats/heightmap-1.0.html , “Each height is the number of 1/5 meter units above -1000 meters”. So, a value of 0 is -1000 meters, and a value of 5000 is 0 meters. A value of 5200 would be 40 meters above the ellipsoid, which is exactly in the range you’re expecting.

Thanks for the explanation Mark. Guess I'm on the right track.