Merge pull request #565 from girder/fix-noninteger-bands

Fix an issue with non-integer GDAL sources.
girder · Mar 11, 2021 · 5ceb84d · 5ceb84d
2 parents 97d099e + 88fae0a
commit 5ceb84d
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -3,7 +3,10 @@
 ## Unreleased
 
 ### Improvements
-- In Girder, prefer geospatial sources for geospatial data
+- In Girder, prefer geospatial sources for geospatial data (#564)
+
+### Bug Fixes
+- The GDAL source failed when getting band ranges on non-integer data (#565)
 
 ## Version 1.4.2
 

diff --git a/sources/gdal/large_image_source_gdal/__init__.py b/sources/gdal/large_image_source_gdal/__init__.py
@@ -258,11 +258,16 @@ def _scanForMinMax(self, dtype, frame=None, analysisSize=1024):
                 }}
             super(GDALFileTileSource, GDALFileTileSource)._scanForMinMax(
                 self, dtype=dtype, frame=frame, analysisSize=analysisSize, **kwargs)
-        self._bandRanges[frame]['min'] = numpy.append(
-            self._bandRanges[frame]['min'], 0)
-        self._bandRanges[frame]['max'] = numpy.append(
-            self._bandRanges[frame]['max'], numpy.iinfo(self._bandRanges[frame]['max'].dtype).max)
-        return
+        # Add the maximum range of the data type to the end of the band
+        # range list.  This changes autoscaling behavior.  For non-integer
+        # data types, this adds the range [0, 1].
+        self._bandRanges[frame]['min'] = numpy.append(self._bandRanges[frame]['min'], 0)
+        try:
+            # only valid for integer dtypes
+            range_max = numpy.iinfo(self._bandRanges[frame]['max'].dtype).max
+        except ValueError:
+            range_max = 1
+        self._bandRanges[frame]['max'] = numpy.append(self._bandRanges[frame]['max'], range_max)
 
     def _getDriver(self):
         """