Earth Engine: How can I loop over an image with 400+bands to make an image collection?

Question

In Google Earth Engine, I have an image with 400+ bands that represent probabilities through time when they are group by 3. The bands look something like this

• prob1_0
• prob2_0
• prob3_0
• prob1_1
• prob2_1
• prob3_1 ...
• prob1_152
• prob2_152
• prob3_152

I want to select the 3 bands starting with 0 to get a separate image that I can add to an image collection. I understand how to do it for 1 image (as coded below) but I want to be able to loop over the list variable to create an image collection with 153 images.

var list = ee.List.sequence(0, 152)
var matchKey = '.*' + list.get(0)
var event0 = ee.Image(image400).select(matchKey).clip(studyArea)
var imageCollection = ee.ImageCollection([event0])

How should I go about it?

Answer 1

You can use map to loop over each entry in the list to select the bands that match the value of matchKey. Finally, you can use ee.ImageCollection.fromImages to create an image collection from the list of images.

var list = ee.List.sequence(0, 152);

var listImages = list.map(function(number){
  var matchKey = '.*' + number;
  var event0 = ee.Image(image400).select(matchKey);
  
  return event0;
});


var imageCollection = ee.ImageCollection.fromImages(listImages);