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I have below rasters:

  1. One with dimension (13646, 7510) where INTEGER pixel values ranges from 0-14.

  2. One with dimension (13646, 7510) where DOUBLE (upto 10 decimal places) pixel values ranges from 0-181257.

I can easily read 1 with RasterToNumPyArray but when I try to read second raster exception raised as below:

return _RasterToNumPyArray(*args, **kwargs)

MemoryError:

I tried with scipy.misc it also gives me error for 2 but reads well 1. I have some problem with GDAL since, I think, I have installed OSGEO64 while I am using Python 2.7 32 bit. So I want to avoid GDAL.

Now what is the way to read 2 in arcpy. I am using rasterio in virtual environment now and I want to get rid of the mess of using virtual environment.

My machine details:

details

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    To do so you need over 1 GB of memory , obviously you don't have it or cannot access
    – FelixIP
    Nov 18, 2016 at 4:33
  • Ahh! but I think I have that resources in my machine?
    – Learner
    Nov 18, 2016 at 4:43
  • 3
    Raster pixel size is generally described in bits; "INTEGER" could refer to anything from 1-, 4-, 8- 13-, 16-, 32-, to 64-bit, which makes it difficult to gauge how much RAM the working raster requires. You state you're using a 32-bit Python, which is your issue -- It generally only has 1.2Gb of heap available to reference all objects.
    – Vince
    Nov 18, 2016 at 11:41
  • @Vince I think you should copy/paste that comment as an answer.
    – PolyGeo
    Jan 23, 2017 at 4:17

1 Answer 1

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Raster pixel size is generally described in bits; "INTEGER" could refer to anything from 1-, 4-, 8- 13-, 16-, 32-, to 64-bit, which makes it difficult to gauge how much RAM the working raster requires. You state you're using a 32-bit Python, which is your issue -- It generally only has 1.2Gb of heap available to reference all objects (including the Python language itself).

An image with dimensions 13646 x 7510 has 102,481,460 pixels. With 64-bit depth (IEEE "double" size), the contiguous memory required is 819,851,680 bytes (~782 Mb). While this is a trivial amount of addressable space in a 64-bit application, it represents 2/3 of the heap in a 32-bit application, so even if you were able to allocate it, it's unlikely you'd be able to manipulate it without generating a memory error.

As a rule, memory errors are encountered due to 32-bit application use (the problem confounds solution in the addressable space). The solution is to use a 64-bit application framework. If you run out of memory with a 64-bit application, then it's a coding issue (somebody hasn't thought through the task well enough).

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