Improve Multiply, Shift, and Add Xform for issue #233

Author: junchaoxia

src/aspire/source/__init__.py

@@ -416,10 +416,10 @@ def invert_contrast(self, batch_size=512):
 
         if signal_mean < noise_mean:
             logger.info('Need to invert contrast')
-            scale_factor = -1.0 * np.ones(self.n)
+            scale_factor = np.array(-1.0)
         else:
             logger.info('No need to invert contrast')
-            scale_factor = 1.0 * np.ones(self.n)
+            scale_factor = np.array(1.0)
 
         logger.info('Adding Scaling Xform to end of generation pipeline')
         self.generation_pipeline.add_xform(Multiply(scale_factor))

src/aspire/source/xform.py

@@ -133,7 +133,21 @@ def __init__(self, factor):
         self.multipliers = factor
 
     def _forward(self, im, indices):
-        return im * self.multipliers[indices]
+        if self.multipliers.size == 1:
+            return im * self.multipliers
+        else:
+            return im * self.multipliers[indices]
+
+    def __str__(self):
+        """
+        Show class name and related scaling information
+        :return: A string of class name and related information
+        """
+        if self.multipliers.size == 1:
+            return (self.__class__.__name__ + ' by same number of '
+                    + str(self.multipliers))
+        else:
+            return self.__class__.__name__ + ' by difference numbers'
 
 
 class Shift(LinearXform):
@@ -151,10 +165,27 @@ def __init__(self, shifts):
         self.n = shifts.shape[0]
 
     def _forward(self, im, indices):
-        return im.shift(self.shifts[indices])
+        if self.n == 1:
+            return im.shift(self.shifts)
+        else:
+            return im.shift(self.shifts[indices])
 
     def _adjoint(self, im, indices):
-        return im.shift(-self.shifts[indices])
+        if self.n == 1:
+           return im.shift(-self.shifts)
+        else:
+            return im.shift(-self.shifts[indices])
+
+    def __str__(self):
+        """
+        Show class name and related shift information
+        :return: A string of class name and related information
+        """
+        if self.n == 1:
+            return (self.__class__.__name__ + ' by same number of '
+                    + str(self.shifts))
+        else:
+            return self.__class__.__name__ + ' by difference numbers'
 
 
 class Downsample(LinearXform):
@@ -219,7 +250,21 @@ def __init__(self, addend):
         self.addend = addend
 
     def _forward(self, im, indices):
-        return im + self.addend[indices]
+        if self.addend.size == 1:
+            return im + self.addend
+        else:
+            return im + self.addend[indices]
+
+    def __str__(self):
+        """
+        Show class name and related Add information
+        :return: A string of class name and related information
+        """
+        if self.addend.size == 1:
+            return (self.__class__.__name__ + ' with same number of '
+                    + str(self.addend))
+        else:
+            return self.__class__.__name__ + ' with different numbers'
 
 
 class FlipXform(Xform):