unnecessary(?) extra dimension when reading GeoImage to array

[F-Sullivan]

when reading a multiband GeoImage to array with img.Read(), there is an extra dimension in the resulting array:

For example, this 80 band image:

        img = gippy.GeoImage(filename)
        arr = img.Read()
        arr.shape
        (80, 1, 548, 4395)

This can be overcome with a numpy function ( arr = img.Read().squeeze() ), but seems an unnecessary step if there isn't a reason to have the extra dimension.

[ircwaves]

Is there any case where you wouldn't want to drop that dimension?

It is a placeholder for a temporal dimension. I guess you wouldn't want to always squeeze. If you were expecting 4 dimensions, but there was only one image, then that dim would disappear.

Does it cause a problem if you don't squeeze?

Sent from a touch screen,
so might be full of typos.

[bhbraswell]

I think that was really the original question - is the dimension potentially used for anything. I was not sure.

On Dec 10, 2015, at 1:44 PM, ircwaves [email protected] wrote:

Is there any case where you wouldn't want to drop that dimension?

It is a placeholder for a temporal dimension. I guess you wouldn't want to always squeeze. If you were expecting 4 dimensions, but there was only one image, then that dim would disappear.

Does it cause a problem if you don't squeeze?

Sent from a touch screen,
so might be full of typos.
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Reply to this email directly or view it on GitHub #7 (comment).

[F-Sullivan]

a temporal dimension makes sense, but I think it would make more sense if it were (time, bands, rows, columns). Then you could call arr = img[0].Read() which would return a shape of (80, 548, 4395) [i.e., the same result as if you were to call arr = img.Read().squeeze() on an image with 4 dimensions (time, bands, rows, cols)]

Is there an advantage or a particular convention for having the temporal dimension expressed band by band instead of entire images expressed over time?

[ircwaves]

Any ordering is fine to me, but I guess I like the idea of GeoImages.Read returning 4D, GeoImage.Read returning 3D, and GeoRaster.Read Returning 2D. Whether it is possible would take some poking around in the code.