Add a singleBand option to the multisource specification

CHANGELOG.md

@@ -7,6 +7,7 @@
 
 ### Improvements
 - Remove NaN values from band information ([#1414](../../pull/1414))
+- Add a singleBand option to the multi-source specification ([#1416](../../pull/1416))
 
 ## 1.26.3
 

large_image/tilesource/base.py

@@ -1560,7 +1560,9 @@
         if hasattr(sc, 'styleIndex'):
             del sc.styleIndex
         sc.output = self._applyStyleFunction(sc.output, sc, 'main')
-        if sc.dtype == 'uint16':
+        if sc.dtype == 'uint8':
+            sc.output = sc.output.astype(np.uint8)
+        elif sc.dtype == 'uint16':
             sc.output = (sc.output * 65535 / 255).astype(np.uint16)
         elif sc.dtype == 'float':
             sc.output /= 255

sources/multi/large_image_source_multi/__init__.py

@@ -333,6 +333,11 @@
                 'layout and size, assume all sources are so similar',
             'type': 'boolean',
         },
+        'singleBand': {
+            'description':
+                'If true, output only the first band of compositied results',
+            'type': 'boolean',
+        },
         'axes': {
             'description': 'A list of additional axes that will be parsed.  '
                            'The default axes are z, t, xy, and c.  It is '
@@ -761,7 +766,7 @@
                             self._nativeMagnification[key] or tsMag.get(key))
                 numChecked += 1
                 tsMeta = ts.getMetadata()
-                if 'bands' in tsMeta:
+                if 'bands' in tsMeta and self._info.get('singleBand') is not True:
                     if not hasattr(self, '_bands'):
                         self._bands = {}
                     self._bands.update(tsMeta['bands'])
@@ -1200,6 +1205,8 @@
                 tile = np.full((self.tileHeight, self.tileWidth, len(colors)),
                                colors,
                                dtype=getattr(self, '_firstdtype', np.uint8))
+        if self._info.get('singleBand'):
+            tile = tile[:, :, 0]
         # We should always have a tile
         return self._outputTile(tile, TILE_FORMAT_NUMPY, x, y, z,
                                 pilImageAllowed, numpyAllowed, **kwargs)