Speed up some tile iteration

CHANGELOG.md

@@ -14,6 +14,7 @@
 - Remove logic for determining DICOMweb transfer syntax ([#1393](../../pull/1393))
 - Speed up tile output ([#1407](../../pull/1407))
 - Speed up import time ([#1408](../../pull/1408))
+- Speed up some tile iteration by reducing the chance of multiple image decodes ([#1410](../../pull/1410))
 
 ### Changes
 - Use an enum for priority constants ([#1400](../../pull/1400))

large_image/tilesource/base.py

@@ -2186,8 +2186,12 @@ def getRegion(self, format=(TILE_FORMAT_IMAGE, ), **kwargs):
                 y0 = 0
             subimage = subimage[:min(subimage.shape[0], regionHeight - y0),
                                 :min(subimage.shape[1], regionWidth - x0)]
-            image = self._addRegionTileToImage(
-                image, subimage, x0, y0, regionWidth, regionHeight, tiled, tile, **kwargs)
+            if tiled:
+                image = self._addRegionTileToTiled(
+                    image, subimage, x0, y0, regionWidth, regionHeight, tile, **kwargs)
+            else:
+                image = self._addRegionTileToImage(
+                    image, subimage, x0, y0, regionWidth, regionHeight, **kwargs)
         # Scale if we need to
         outWidth = int(math.floor(outWidth))
         outHeight = int(math.floor(outHeight))
@@ -2209,7 +2213,7 @@ def getRegion(self, format=(TILE_FORMAT_IMAGE, ), **kwargs):
         return _encodeImage(image, format=format, **kwargs)
 
     def _addRegionTileToImage(
-            self, image, subimage, x, y, width, height, tiled=False, tile=None, **kwargs):
+            self, image, subimage, x, y, width, height, tile=None, **kwargs):
         """
         Add a subtile to a larger image.
 
@@ -2221,12 +2225,8 @@ def _addRegionTileToImage(
             the output image.
         :param width: the output image size.
         :param height: the output image size.
-        :param tiled: true to generate a tiled output image.
-        :param tile: the original tile record with the current scale, etc.
         :returns: the output image record.
         """
-        if tiled:
-            return self._addRegionTileToTiled(image, subimage, x, y, width, height, tile, **kwargs)
         if image is None:
             if (x, y, width, height) == (0, 0, subimage.shape[1], subimage.shape[0]):
                 return subimage
@@ -2473,9 +2473,12 @@ def tileFrames(self, format=(TILE_FORMAT_IMAGE, ), frameList=None,
                 self.logger.debug(
                     'Tiling frame %d (%d/%d), offset %dx%d',
                     frame, idx, len(frameList), offsetX, offsetY)
-            image = self._addRegionTileToImage(
-                image, subimage, offsetX, offsetY, outWidth, outHeight, tiled,
-                tile=tile, **kwargs)
+            if tiled:
+                image = self._addRegionTileToTiled(
+                    image, subimage, offsetX, offsetY, outWidth, outHeight, tile, **kwargs)
+            else:
+                image = self._addRegionTileToImage(
+                    image, subimage, offsetX, offsetY, outWidth, outHeight, **kwargs)
         if tiled:
             return self._encodeTiledImage(image, outWidth, outHeight, iterInfo, **kwargs)
         return _encodeImage(image, format=format, **kwargs)

large_image/tilesource/tiledict.py

@@ -165,7 +165,8 @@ def __getitem__(self, key, *args, **kwargs):
             if not self.retile:
                 tileData = self.source.getTile(
                     self.x, self.y, self.level,
-                    pilImageAllowed=True, numpyAllowed=True,
+                    pilImageAllowed=True,
+                    numpyAllowed='always' if TILE_FORMAT_NUMPY in self.format else True,
                     sparseFallback=True, frame=self.frame)
                 if self.crop:
                     tileData, _ = _imageToNumpy(tileData)
@@ -217,6 +218,10 @@ def __getitem__(self, key, *args, **kwargs):
                     raise exceptions.TileSourceError(
                         'Cannot yield tiles in desired format %r' % (
                             self.format, ))
+            elif (TILE_FORMAT_PIL not in self.format and TILE_FORMAT_NUMPY in self.format and
+                    not isinstance(tileData, PIL.Image.Image)):
+                tileData, _ = _imageToNumpy(tileData)
+                tileFormat = TILE_FORMAT_NUMPY
             else:
                 tileData = pilData if pilData is not None else _imageToPIL(tileData)
                 tileFormat = TILE_FORMAT_PIL