Applies a reducer across all of the images in a collection.

If the reducer has a single input, it will be applied separately to each band of the collection; otherwise it must have the same number of inputs as the collection has bands.

The reducer output names determine the names of the output bands: reducers with multiple inputs will use the output names directly, while reducers with a single input will prefix the output name with the input band name (e.g. '10_mean', '20_mean', etc.).

ImageCollection.reduce(reducer, parallelScale)Image
this: collectionImageCollection

The image collection to reduce.


The reducer to apply to the given collection.

parallelScaleFloat, default: 1

A scaling factor used to limit memory use; using a larger parallelScale (e.g. 2 or 4) may enable computations that run out of memory with the default.