Merge branch 'faster-make-argb' into develop

- Speed improvements in functions.makeARGB
- ImageItem is faster by avoiding makeQImage(transpose=True)

pyqtgraph/functions.py

@@ -782,25 +782,6 @@ def makeARGB(data, lut=None, levels=None, scale=None, useRGBA=False):
     if levels is not None and not isinstance(levels, np.ndarray):
         levels = np.array(levels)
     
-    ## sanity checks
-    #if data.ndim == 3:
-        #if data.shape[2] not in (3,4):
-            #raise Exception("data.shape[2] must be 3 or 4")
-        ##if lut is not None:
-            ##raise Exception("can not use lookup table with 3D data")
-    #elif data.ndim != 2:
-        #raise Exception("data must be 2D or 3D")
-        
-    #if lut is not None:
-        ##if lut.ndim == 2:
-            ##if lut.shape[1] :
-                ##raise Exception("lut.shape[1] must be 3 or 4")
-        ##elif lut.ndim != 1:
-            ##raise Exception("lut must be 1D or 2D")
-        #if lut.dtype != np.ubyte:
-            #raise Exception('lookup table must have dtype=ubyte (got %s instead)' % str(lut.dtype))
-            
-
     if levels is not None:
         if levels.ndim == 1:
             if len(levels) != 2:
@@ -813,16 +794,6 @@ def makeARGB(data, lut=None, levels=None, scale=None, useRGBA=False):
         else:
             print(levels)
             raise Exception("levels argument must be 1D or 2D.")
-        #levels = np.array(levels)
-        #if levels.shape == (2,):
-            #pass
-        #elif levels.shape in [(3,2), (4,2)]:
-            #if data.ndim == 3:
-                #raise Exception("Can not use 2D levels with 3D data.")
-            #if lut is not None:
-                #raise Exception('Can not use 2D levels and lookup table together.')
-        #else:
-            #raise Exception("Levels must have shape (2,) or (3,2) or (4,2)")
         
     prof.mark('1')
 
@@ -865,8 +836,6 @@ def makeARGB(data, lut=None, levels=None, scale=None, useRGBA=False):
 
     ## copy data into ARGB ordered array
     imgData = np.empty(data.shape[:2]+(4,), dtype=np.ubyte)
-    if data.ndim == 2:
-        data = data[..., np.newaxis]
 
     prof.mark('4')
 
@@ -875,20 +844,26 @@ def makeARGB(data, lut=None, levels=None, scale=None, useRGBA=False):
     else:
         order = [2,1,0,3] ## for some reason, the colors line up as BGR in the final image.
         
-    if data.shape[2] == 1:
+    if data.ndim == 2:
+        # This is tempting:
+        #   imgData[..., :3] = data[..., np.newaxis]
+        # ..but it turns out this is faster:
         for i in range(3):
-            imgData[..., order[i]] = data[..., 0]    
+            imgData[..., i] = data
+    elif data.shape[2] == 1:
+        for i in range(3):
+            imgData[..., i] = data[..., 0]
     else:
         for i in range(0, data.shape[2]):
-            imgData[..., order[i]] = data[..., i]    
+            imgData[..., i] = data[..., order[i]] 
         
     prof.mark('5')
         
-    if data.shape[2] == 4:
-        alpha = True
-    else:
+    if data.ndim == 2 or data.shape[2] == 3:
         alpha = False
         imgData[..., 3] = 255
+    else:
+        alpha = True
         
     prof.mark('6')
         

pyqtgraph/graphicsItems/ImageItem.py

@@ -260,8 +260,8 @@ class ImageItem(GraphicsObject):
         #print lut.shape
         #print self.lut
             
-        argb, alpha = fn.makeARGB(self.image, lut=lut, levels=self.levels)
-        self.qimage = fn.makeQImage(argb, alpha)
+        argb, alpha = fn.makeARGB(self.image.transpose((1, 0, 2)[:self.image.ndim]), lut=lut, levels=self.levels)
+        self.qimage = fn.makeQImage(argb, alpha, transpose=False)
         prof.finish()