all() : For only one image, this function checks that all bands of the image are True (i.e. !=0) and outputs
a singleband boolean raster
For several images, this function checks that all images are True (i.e. !=0) and outputs
a boolean raster, with as many bands as the inputs
any() : For only one image, this function checks that at least one band of the image is True (i.e. !=0) and outputs
a singleband boolean raster
For several images, this function checks that at least one of the images is True (i.e. !=0) and outputs
a boolean raster, with as many bands as the inputs