Add an OverviewCreationError

Resolves #1333

CHANGES.txt

@@ -6,6 +6,9 @@ Changes
 
 Bug fixes:
 
+- If the build_overviews method of a dataset is passed a list of factors that
+  specify more than one 1x1 pixel overview (#1333), Rasterio raises an
+  exception.
 - Calling calculate_default_transform for large extents should no longer result
   in the out of memory error reported in #1131. The rio-warp command should
   also now run more quickly and with a smaller memory footprint.

rasterio/_io.pyx

@@ -6,6 +6,7 @@ from __future__ import absolute_import
 include "directives.pxi"
 include "gdal.pxi"
 
+from collections import Counter
 import logging
 import sys
 import uuid
@@ -24,7 +25,7 @@ from rasterio.enums import ColorInterp, MaskFlags, Resampling
 from rasterio.errors import (
     CRSError, DriverRegistrationError, RasterioIOError,
     NotGeoreferencedWarning, NodataShadowWarning, WindowError,
-    UnsupportedOperation
+    UnsupportedOperation, OverviewCreationError
 )
 from rasterio.sample import sample_gen
 from rasterio.transform import Affine
@@ -1549,6 +1550,11 @@ cdef class DatasetWriterBase(DatasetReaderBase):
                     ['Resampling.{0}'.format(Resampling(k).name) for k in
                      resampling_map.keys()])))
 
+        # Check factors
+        ovr_shapes = Counter([(int((self.height + f - 1) / f), int((self.width + f - 1) / f)) for f in factors])
+        if ovr_shapes[(1, 1)] > 1:
+            raise OverviewCreationError("Too many overviews levels of 1x1 dimension were requested")
+
         # Allocate arrays.
         if factors:
             factors_c = <int *>CPLMalloc(len(factors)*sizeof(int))

rasterio/errors.py

@@ -98,3 +98,7 @@ class WarpOptionsError(RasterioError):
 
 class UnsupportedOperation(RasterioError):
     """Raised when reading from a file opened in 'w' mode"""
+
+
+class OverviewCreationError(RasterioError):
+    """Raised when creation of an overview fails"""

tests/test_overviews.py

@@ -9,6 +9,8 @@
 import rasterio
 from rasterio.enums import Resampling
 from rasterio.env import GDALVersion
+from rasterio.errors import OverviewCreationError
+
 
 gdal_version = GDALVersion()
 
@@ -79,3 +81,12 @@ def test_test_unsupported_algo(data):
         with rasterio.open(inputfile, 'r+') as src:
             overview_factors = [2, 4]
             src.build_overviews(overview_factors, resampling=Resampling.q1)
+
+
+def test_issue1333(data):
+    """Fail if asked to create more than one 1x1 overview"""
+    inputfile = str(data.join('RGB.byte.tif'))
+    with pytest.raises(OverviewCreationError):
+        with rasterio.open(inputfile, 'r+') as src:
+            overview_factors = [1024, 2048]
+            src.build_overviews(overview_factors, resampling=Resampling.average)