From da711d17cdac390e75ed6e7d3d3b5c14965f814e Mon Sep 17 00:00:00 2001
From: "Harle, Antoine (Contracteur)" <Antoine.Harle@Teledyne.com>
Date: Wed, 22 Jan 2020 17:30:27 -0500
Subject: [PATCH] Transformations comments

---
 higher/transformations.py | 198 ++++++++++++++++++++------------------
 1 file changed, 106 insertions(+), 92 deletions(-)

diff --git a/higher/transformations.py b/higher/transformations.py
index c6cefde..f7b661e 100755
--- a/higher/transformations.py
+++ b/higher/transformations.py
@@ -18,11 +18,18 @@ import torch
 import kornia
 import random
 
-### Available TF for Dataug ###
 
+TF_no_mag={'Identity', 'FlipUD', 'FlipLR', 'Random', 'RandBlend'} #TF that don't have use for magnitude parameter.
+TF_no_grad={'Solarize', 'Posterize', '=Solarize', '=Posterize'} #TF which implemetation doesn't allow gradient propagaition.
+TF_ignore_mag= TF_no_mag | TF_no_grad #TF for which magnitude should be ignored (Magnitude fixed).
+
+PARAMETER_MAX = 1  # What is the max 'level' a transform could be predicted
+PARAMETER_MIN = 0.1 # What is the min 'level' a transform could be predicted
+
+### Available TF for Dataug ###
 # Dictionnary mapping tranformations identifiers to their function.
 # Each value of the dict should be a lambda function taking a (batch of data, magnitude of transformations) tuple as input and returns a batch of data.
-TF_dict={ #Dataugv5
+TF_dict={ #Dataugv5+
     ## Geometric TF ##
     'Identity' : (lambda x, mag: x),
     'FlipUD' : (lambda x, mag: flipUD(x)),
@@ -70,18 +77,12 @@ TF_dict={ #Dataugv5
     'Random':(lambda x, mag: torch.rand_like(x)),
     'RandBlend': (lambda x, mag: blend(x,torch.rand_like(x), alpha=torch.tensor(0.7,device=mag.device).expand(x.shape[0]))),
 
-    #Non fonctionnel
+    #Not ready for use
     #'Auto_Contrast': (lambda mag: None), #Pas opti pour des batch (Super lent)
     #'Equalize': (lambda mag: None),
 }
 
-TF_no_mag={'Identity', 'FlipUD', 'FlipLR', 'Random', 'RandBlend'} #TF that don't have use for magnitude parameter.
-TF_no_grad={'Solarize', 'Posterize', '=Solarize', '=Posterize'} #TF which implemetation doesn't allow gradient propagaition.
-TF_ignore_mag= TF_no_mag | TF_no_grad #TF for which magnitude should be ignored (Magnitude fixed).
-
-PARAMETER_MAX = 1  # What is the max 'level' a transform could be predicted
-PARAMETER_MIN = 0.1 # What is the min 'level' a transform could be predicted
-
+## Image type cast ##
 def int_image(float_image):
     """Convert a float Tensor/Image to an int Tensor/Image.
 
@@ -109,19 +110,7 @@ def float_image(int_image):
     """
     return int_image.type(torch.float)/255.
 
-#def rand_inverse(value):
-#    return  value if random.random() < 0.5 else -value
-
-#def rand_int(mag, maxval, minval=None): #[(-maxval,minval), maxval]
-#  real_max = int_parameter(mag, maxval=maxval)
-#  if not minval : minval = -real_max
-#  return random.randint(minval, real_max)
-
-#def rand_float(mag, maxval, minval=None): #[(-maxval,minval), maxval]
-#  real_max = float_parameter(mag, maxval=maxval)
-#  if not minval : minval = -real_max
-#  return random.uniform(minval, real_max)
-
+## Parameters utils ##
 def rand_floats(size, mag, maxval, minval=None):
     """Generate a batch of random values.
 
@@ -188,20 +177,9 @@ def float_parameter(level, maxval):
     """
 
     #return float(level) * maxval / PARAMETER_MAX
-    return (level * maxval / PARAMETER_MAX)#.to(torch.float)
-
-#def int_parameter(level, maxval): #Perte de gradient
-    """Helper function to scale `val` between 0 and maxval .
-    Args:
-    level: Level of the operation that will be between [0, `PARAMETER_MAX`].
-    maxval: Maximum value that the operation can have. This will be scaled
-      to level/PARAMETER_MAX.
-    Returns:
-    An int that results from scaling `maxval` according to `level`.
-    """
-    #return int(level * maxval / PARAMETER_MAX)
-    #  return (level * maxval / PARAMETER_MAX) 
+    return (level * maxval / PARAMETER_MAX)#.to(torch.float) 
 
+## Tranformations ##
 def flipLR(x):
     """Flip horizontaly/Left-Right images.
         
@@ -343,16 +321,101 @@ def sharpeness(x, sharpness_factor):
     return blend(smooth_x, x, sharpness_factor).clamp(min=0.0,max=1.0) #Expect image in the range of [0, 1]
 
 def posterize(x, bits):
-  bits = bits.type(torch.uint8) #Perte du gradient
-  x = int_image(x) #Expect image in the range of [0, 1]
+    """Reduce the number of bits for each color channel.
 
-  mask = ~(2 ** (8 - bits) - 1).type(torch.uint8)
+        Be warry that the cast to integers block the gradient propagation.
+    Args:
+        x (Tensor): Batch of images.
+        bits (Tensor): The number of bits to keep for each channel (1-8).
 
-  (batch_size, channels, h, w) = x.shape
-  mask = mask.unsqueeze(dim=1).expand(-1,channels).unsqueeze(dim=2).expand(-1,channels, h).unsqueeze(dim=3).expand(-1,channels, h, w) #Il y a forcement plus simple ...
+    Returns:
+        (Tensor): Batch of posterized images.
+    """
+    bits = bits.type(torch.uint8) #Perte du gradient
+    x = int_image(x) #Expect image in the range of [0, 1]
 
-  return float_image(x & mask)
+    mask = ~(2 ** (8 - bits) - 1).type(torch.uint8)
 
+    (batch_size, channels, h, w) = x.shape
+    mask = mask.unsqueeze(dim=1).expand(-1,channels).unsqueeze(dim=2).expand(-1,channels, h).unsqueeze(dim=3).expand(-1,channels, h, w) #Il y a forcement plus simple ...
+
+    return float_image(x & mask)
+
+def solarize(x, thresholds):
+    """Invert all pixel values above a threshold.
+
+        Be warry that the use of the inequality (x>tresholds) block the gradient propagation.
+    Args:
+        x (Tensor): Batch of images.
+        thresholds (Tensor):  All pixels above this level are inverted
+
+    Returns:
+        (Tensor): Batch of solarized images.
+    """
+    batch_size, channels, h, w = x.shape
+    #imgs=[]
+    #for idx, t in enumerate(thresholds): #Operation par image
+    #  mask = x[idx] > t #Perte du gradient
+    #In place
+    #  inv_x = 1-x[idx][mask]
+    #  x[idx][mask]=inv_x
+    #
+
+    #Out of place
+    #  im = x[idx]
+    #  inv_x = 1-im[mask]
+
+    #  imgs.append(im.masked_scatter(mask,inv_x))
+
+    #idxs=torch.tensor(range(x.shape[0]), device=x.device)
+    #idxs=idxs.unsqueeze(dim=1).expand(-1,channels).unsqueeze(dim=2).expand(-1,channels, h).unsqueeze(dim=3).expand(-1,channels, h, w) #Il y a forcement plus simple ...
+    #x=x.scatter(dim=0, index=idxs, src=torch.stack(imgs))
+    #
+
+    thresholds = thresholds.unsqueeze(dim=1).expand(-1,channels).unsqueeze(dim=2).expand(-1,channels, h).unsqueeze(dim=3).expand(-1,channels, h, w) #Il y a forcement plus simple ...
+    x=torch.where(x>thresholds,1-x, x)
+
+    #x=x.min(thresholds)
+    #inv_x = 1-x[mask]
+    #x=x.where(x<thresholds,1-x)
+    #x[mask]=inv_x
+    #x=x.masked_scatter(mask, inv_x)
+
+    return x
+
+def blend(x,y,alpha):
+    """Creates a new images by interpolating between two input images, using a constant alpha.
+        
+        x and y should have the same size.
+        alpha should have the same batch size as the images.
+
+        Apply batch wise :
+            out = image1 * (1.0 - alpha) + image2 * alpha
+
+    Args:
+        x (Tensor): Batch of images.
+        y (Tensor): Batch of images.
+        alpha (Tensor):  The interpolation alpha factor for each images.
+    Returns:
+        (Tensor): Batch of solarized images.
+    """
+    #return kornia.add_weighted(src1=x, alpha=(1-alpha), src2=y, beta=alpha, gamma=0) #out=src1∗alpha+src2∗beta+gamma #Ne fonctionne pas pour des batch de alpha
+
+    if not isinstance(x, torch.Tensor):
+        raise TypeError("x should be a tensor. Got {}".format(type(x)))
+
+    if not isinstance(y, torch.Tensor):
+        raise TypeError("y should be a tensor. Got {}".format(type(y)))
+
+    assert(x.shape==y.shape and x.shape[0]==alpha.shape[0])
+
+    (batch_size, channels, h, w) = x.shape
+    alpha = alpha.unsqueeze(dim=1).expand(-1,channels).unsqueeze(dim=2).expand(-1,channels, h).unsqueeze(dim=3).expand(-1,channels, h, w) #Il y a forcement plus simple ...
+    res = x*(1-alpha) + y*alpha
+
+    return res
+
+#Not working
 def auto_contrast(x): #PAS OPTIMISE POUR DES BATCH #EXTRA LENT
   # Optimisation : Application de LUT efficace / Calcul d'histogramme par batch/channel
   print("Warning : Pas encore check !")
@@ -401,53 +464,4 @@ def equalize(x): #PAS OPTIMISE POUR DES BATCH
       #print(chan.shape)
       hist = torch.histc(chan, bins=256, min=0, max=255) #PAS DIFFERENTIABLE
 
-  return float_image(x)
-
-def solarize(x, thresholds):
-  batch_size, channels, h, w = x.shape
-  #imgs=[]
-  #for idx, t in enumerate(thresholds): #Operation par image
-  #  mask = x[idx] > t #Perte du gradient
-    #In place
-  #  inv_x = 1-x[idx][mask]
-  #  x[idx][mask]=inv_x
-    #
-
-  #Out of place
-  #  im = x[idx]
-  #  inv_x = 1-im[mask]
-
-  #  imgs.append(im.masked_scatter(mask,inv_x))
-
-  #idxs=torch.tensor(range(x.shape[0]), device=x.device)
-  #idxs=idxs.unsqueeze(dim=1).expand(-1,channels).unsqueeze(dim=2).expand(-1,channels, h).unsqueeze(dim=3).expand(-1,channels, h, w) #Il y a forcement plus simple ...
-  #x=x.scatter(dim=0, index=idxs, src=torch.stack(imgs))
-  #
-
-  thresholds = thresholds.unsqueeze(dim=1).expand(-1,channels).unsqueeze(dim=2).expand(-1,channels, h).unsqueeze(dim=3).expand(-1,channels, h, w) #Il y a forcement plus simple ...
-  #print(thresholds.grad_fn)
-  x=torch.where(x>thresholds,1-x, x)
-  #print(mask.grad_fn)
-
-  #x=x.min(thresholds)
-  #inv_x = 1-x[mask]
-  #x=x.where(x<thresholds,1-x)
-  #x[mask]=inv_x
-  #x=x.masked_scatter(mask, inv_x)
-
-  return x
-
-def blend(x,y,alpha): #out = image1 * (1.0 - alpha) + image2 * alpha
-    #return kornia.add_weighted(src1=x, alpha=(1-alpha), src2=y, beta=alpha, gamma=0) #out=src1∗alpha+src2∗beta+gamma #Ne fonctionne pas pour des batch de alpha
-
-    if not isinstance(x, torch.Tensor):
-        raise TypeError("x should be a tensor. Got {}".format(type(x)))
-
-    if not isinstance(y, torch.Tensor):
-        raise TypeError("y should be a tensor. Got {}".format(type(y)))
-
-    (batch_size, channels, h, w) = x.shape
-    alpha = alpha.unsqueeze(dim=1).expand(-1,channels).unsqueeze(dim=2).expand(-1,channels, h).unsqueeze(dim=3).expand(-1,channels, h, w) #Il y a forcement plus simple ...
-    res = x*(1-alpha) + y*alpha
-
-    return res
+  return float_image(x)
\ No newline at end of file