Add/display all images of mycollection in google earth engine

Question

I started with GoogleEngine recently and I was wondering how I can display all images of my collection as layers. I guess there is a better way than manually copy past / typing:

 var img1 = ee.Image('COPERNICUS/.....);
 var img2 = ....;
 var imgx = ....

 Map.addLayer (img1);
 Map.addLayer(img2);
 Map.addLayer(imgx)....

This questions was already asked in 2017 but I was unable to retrace the link/shared google group...

Displaying a lot of layers simultaneously would take a lot of time. — Dima Chubarov, May 30 '18 at 11:05
My images are clipped, and since I can manually display 15 images, I guess "the time it takes" is not the problem... I',m just looking for an auto-way — Andreas Eugster, May 30 '18 at 15:49

Kersten · Accepted Answer · 2020-04-12T11:33:16.727

9

If you are only displaying a reasonable amount of images you can use a client-side function to add each image as a layer to the map.

Here's an example using 15 images in a polygon you would draw and rename roi.

var s2 = ee.ImageCollection("COPERNICUS/S2")
  .filterBounds(roi)
  .select("B2")
  .limit(15)

function addImage(image) { // display each image in collection
  var id = image.id
  var image = ee.Image(image.id)
  Map.addLayer(image)
}

s2.evaluate(function(s2) {  // use map on client-side
  s2.features.map(addImage)
})

edited Apr 12 '20 at 11:33

answered May 30 '18 at 20:08

Kersten

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the above code gives the output but displays only one band as constant. how to go about it – rao Jan 22 '20 at 12:05
1

@Kersten, could you please explain why we need the id inside of the addImage() function? – cengstro Feb 07 '22 at 00:36
The ID is used to identify what image to display as part of the map function. You could shorten the code to a single line but I prefer readability over brevity for examples. – Kersten Feb 12 '22 at 08:21
I'm also puzzled by the id part... are you actually using the id object (i.e. doing image.image.id), or is `id unused in your script? – Matifou Jun 14 '22 at 10:14

score 7 · Answer 2 · answered Jun 19 '18 at 09:09

In addition to the answer of Kersten, you could also add this piece of code to easily view all the images by moving a slider:

var slider = ui.Slider();
slider.onSlide(function(value) {
  var int_value = value * (Map.layers().length() - 1) >> 0;
  Map.layers().get(int_value).setOpacity(1);
  for (var i = int_value + 1; i < Map.layers().length(); i++) {
    Map.layers().get(i).setOpacity(0);
}
});
print(slider);

It does this by changing the opacity of each layer.

Add/display all images of mycollection in google earth engine

2 Answers2

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