Merge pull request #593 from girder/simplify-thumbnail-code

Simplify thumbnail generation.

girder/test_girder/test_tiles_rest.py

@@ -836,14 +836,6 @@ def testGetTileSource(server, admin, fsAssetstore):
     image, mime = source.getThumbnail(encoding='JPEG', width=200)
     assert image[:len(utilities.JPEGHeader)] == utilities.JPEGHeader
 
-    # Test the level0 thumbnail code path
-    image, mime = source.getThumbnail(
-        encoding='PNG', width=200, height=100, levelZero=True, fill='blue')
-    assert image[:len(utilities.PNGHeader)] == utilities.PNGHeader
-    (width, height) = struct.unpack('!LL', image[16:24])
-    assert width == 200
-    assert height == 100
-
 
 @pytest.mark.usefixtures('unbindLargeImage')
 @pytest.mark.plugin('large_image')

large_image/tilesource/base.py

@@ -1694,17 +1694,16 @@ def getTileMimeType(self):
         return TileOutputMimeTypes.get(self.encoding, 'image/jpeg')
 
     @methodcache()
-    def getThumbnail(self, width=None, height=None, levelZero=False, **kwargs):
+    def getThumbnail(self, width=None, height=None, **kwargs):
         """
         Get a basic thumbnail from the current tile source.  Aspect ratio is
         preserved.  If neither width nor height is given, a default value is
         used.  If both are given, the thumbnail will be no larger than either
-        size.
+        size.  A thumbnail has the same options as a region except that it
+        always includes the entire image and has a default size of 256 x 256.
 
         :param width: maximum width in pixels.
         :param height: maximum height in pixels.
-        :param levelZero: if true, always use the level zero tile.  Otherwise,
-            the thumbnail is generated so that it is never upsampled.
         :param kwargs: optional arguments.  Some options are encoding,
             jpegQuality, jpegSubsampling, and tiffCompression.
         :returns: thumbData, thumbMime: the image data and the mime type.
@@ -1714,35 +1713,10 @@ def getThumbnail(self, width=None, height=None, levelZero=False, **kwargs):
             raise ValueError('Invalid width or height.  Minimum value is 2.')
         if width is None and height is None:
             width = height = 256
-        # There are two code paths for generating thumbnails.  If
-        # alwaysUseLevelZero is True, then the the thumbnail is generated more
-        # swiftly, but may look poor.  We may want to add a parameter for this
-        # option, or only use the high-quality results.
-        if not levelZero:
-            params = dict(kwargs)
-            params['output'] = {'maxWidth': width, 'maxHeight': height}
-            params.pop('region', None)
-            return self.getRegion(**params)
-        metadata = self.getMetadata()
-        tileData = self.getTile(0, 0, 0)
-        image = _imageToPIL(tileData)
-        imageWidth = int(math.floor(
-            metadata['sizeX'] * 2 ** -(metadata['levels'] - 1)))
-        imageHeight = int(math.floor(
-            metadata['sizeY'] * 2 ** -(metadata['levels'] - 1)))
-        image = image.crop((0, 0, imageWidth, imageHeight))
-
-        if width or height:
-            maxWidth, maxHeight = width, height
-            width, height, calcScale = self._calculateWidthHeight(
-                width, height, imageWidth, imageHeight)
-
-            image = image.resize(
-                (width, height),
-                PIL.Image.BICUBIC if width > imageWidth else PIL.Image.LANCZOS)
-            if kwargs.get('fill') and maxWidth and maxHeight:
-                image = _letterboxImage(image, maxWidth, maxHeight, kwargs['fill'])
-        return _encodeImage(image, **kwargs)
+        params = dict(kwargs)
+        params['output'] = {'maxWidth': width, 'maxHeight': height}
+        params.pop('region', None)
+        return self.getRegion(**params)
 
     def getPreferredLevel(self, level):
         """

sources/gdal/large_image_source_gdal/__init__.py

@@ -879,17 +879,17 @@ def _getRegionBounds(self, metadata, left=None, top=None, right=None,
             metadata, left, top, right, bottom, width, height, units, **kwargs)
 
     @methodcache()
-    def getThumbnail(self, width=None, height=None, levelZero=False, **kwargs):
+    def getThumbnail(self, width=None, height=None, **kwargs):
         """
         Get a basic thumbnail from the current tile source.  Aspect ratio is
         preserved.  If neither width nor height is given, a default value is
         used.  If both are given, the thumbnail will be no larger than either
-        size.
+        size.  A thumbnail has the same options as a region except that it
+        always includes the entire image if there is no projection and has a
+        default size of 256 x 256.
 
         :param width: maximum width in pixels.
         :param height: maximum height in pixels.
-        :param levelZero: if true, always use the level zero tile.  Otherwise,
-            the thumbnail is generated so that it is never upsampled.
         :param kwargs: optional arguments.  Some options are encoding,
             jpegQuality, jpegSubsampling, and tiffCompression.
         :returns: thumbData, thumbMime: the image data and the mime type.
@@ -904,7 +904,7 @@ def getThumbnail(self, width=None, height=None, levelZero=False, **kwargs):
             params['output'] = {'maxWidth': width, 'maxHeight': height}
             params['region'] = {'units': 'projection'}
             return self.getRegion(**params)
-        return super().getThumbnail(width, height, levelZero, **kwargs)
+        return super().getThumbnail(width, height, **kwargs)
 
     def toNativePixelCoordinates(self, x, y, proj=None, roundResults=True):
         """