Converting a FeatureCollection to an ImageCollection

Question

I am trying to convert a FeatureCollection (a bit heavy one though) to an Imagecollection. It seems that the job has been done successfully, however, I can't take any further steps with the Imagecollection such as clipping or reducing, and I cannot address the issue, Ang thoughts on this? Here is the link to the code:

https://code.earthengine.google.com/31de43e96b218cac08248e9177800d7e

Answer 1

This is due to the client/server split of Earth Engine.

The Earth Engine servers know that if you map() a feature collection and each result feature is an image, then the result collection can be an image collection. But the Earth Engine client — the JavaScript (or Python) functions you actually call to define your computation — don't look at the map() and conclude "this always returns an ee.Image". So, as far as the client knows, you're working on a FeatureCollection, not an ImageCollection, and can't use any methods of ImageCollection.

The solution is to write a cast, to inform the client that the result will definitely be an ImageCollection:

//                  add this to your script
//                    ↓        ↓       ↓
var imageCollection = ee.ImageCollection(featureCollection.map(function (feature) {
  return ee.Image.constant(feature.get('myProperty')).rename('myBand');
}));