LossModules.py

import torch
import torch.nn as nn
import torchvision

# Define an nn Module to compute content loss in-place
class ContentLoss(nn.Module):
    def __init__(self, strength, normalize):
      super(ContentLoss, self).__init__()
      self.strength = strength
      self.target = torch.Tensor()
      self.normalize = 'false'
      self.loss = 0
      self.crit = nn.MSELoss()
      self.mode = None
          
    def updateOutput(self, input):
      if self.mode == 'loss':
        self.loss = self.crit.updateOutput(input, self.target) * self.strength #Forward
      elif self.mode == 'capture':
        self.target.resize_as_(input).copy_(input)
      self.output = input 
      return self.output
  
    def updateGradInput(self, input, gradOutput):
      if self.mode == 'loss':
        if input.nelement() == self.target.nelement():
          self.gradInput = self.crit.updateGradInput(input, self.target) #Backward
        if self.normalize:
          self.gradInput.div(torch.norm(self.gradInput, 1) + 1e-8) # Normalize Gradients
        self.gradInput.mul(self.strength)
        self.gradInput.add(gradOutput)
      else:
        self.target.resize_as_(gradOutput).copy_(gradOutput)
      return self.gradInput
 

class GramMatrix(nn.Module):
   def __init__(self):
     super(GramMatrix, self).__init__()

   def updateOutput(self, input):
     assert input.dim() == 3
     C, H, W = input.size(0), input.size(1), input.size(2)
     x_flat = input.view(C, H * W)
     self.output.resize_(C, C)
     self.output = torch.mm(x_flat, x_flat.t())
     return self.output

   def updateGradInput(self, input, gradOutput):
     assert input.dim() == 3 and input.size(0)
     C, H, W = input.size(0), input.size(1), input.size(2)
     x_flat = input.view(C, H * W)
     #self.gradInput.resize(C, H * W).mm(gradOutput, x_flat)
     self.gradInput.resize_(C, H * W)#.mm(gradOutput, x_flat)
     self.gradInput = torch.mm(gradOutput, x_flat) #, out=self.gradInput
     self.gradInput.addmm(gradOutput.t(), x_flat)
     self.gradInput = self.gradInput.view(C, H, W)
     return self.gradInput


# Define an nn Module to compute style loss in-place
class StyleLoss(nn.Module):
    def __init__(self, strength, normalize):
      super(StyleLoss, self).__init__()
      self.normalize = 'false'
      self.strength = strength
      self.target = torch.Tensor()
      self.mode = None
      self.loss = 0
      self.gram = GramMatrix()
      self.blend_weight = None
      self.G = None
      self.crit = nn.MSELoss()
        
    def updateOutput(self, input):
      self.G = self.gram.updateOutput(input) # Forward Gram
      self.G.div(input.nelement()) #Lua (Fix): self.G:div(input:nElement())
      if self.mode == 'capture':
        if self.blend_weight == None:
          self.target.resize_as_(self.G).copy_(self.G)
        elif self.target.nelement() == 0:
          self.target.resize_as_(self.G).copy_(self.G).mul_(self.blend_weight)
        else:
          self.target.add(self.blend_weight, self.G)
      elif self.mode == 'loss':
        self.loss = self.strength * self.crit.forward(self.G, self.target) #Forward
      self.output = input
      return self.output

    def updateGradInput(self, input, gradOutput):
      if self.mode == 'loss':
        dG = self.crit.updateGradInput(self.G, self.target) # Backward
        #dG.div(input.nelement())
        self.gradInput = self.gram.updateGradInput(input, dG) # Gram Backward
        if self.normalize:
          self.gradInput.div(torch.norm(self.gradInput, 1) + 1e-8) # Normalize Gradients
        self.gradInput.mul(self.strength)
        self.gradInput.add(gradOutput)
      else: 
        self.gradInput = gradOutput
      return self.gradInput

st.py

import torch
import torch.nn as nn
import torchvision
import torchvision.models as models
import torchvision.transforms as transforms
from torch.autograd import Variable
import torch.optim as optim

from PIL import Image
from LossModules import ContentLoss
from LossModules import StyleLoss
from LossModules import GramMatrix

import argparse
parser = argparse.ArgumentParser()
# Basic options
parser.add_argument("-style_image", help="Style target image", default='examples/inputs/seated-nude.jpg')
parser.add_argument("-content_image", help="Content target image", default='examples/inputs/tubingen.jpg')
parser.add_argument("-image_size", help="Maximum height / width of generated image", type=int, default=512)
# Optimization options
parser.add_argument("-num_iterations", help="iterations", type=int, default=1000)
parser.add_argument("-optimizer", help="optimiser", default="lbfgs", choices=["lbfgs", "adam"])
params = parser.parse_args()

use_cuda = torch.cuda.is_available()
dtype = torch.cuda.FloatTensor if use_cuda else torch.FloatTensor


def ImageSetup(image_name, image_size):
    image = Image.open(image_name)
    image = image.convert('RGB')
    loader = transforms.Compose([transforms.Resize((image_size)), transforms.ToTensor()])  # resize and convert to tensor
    image = Variable(loader(image))
    #image = image.permute(2, 1, 0)
    image = image.unsqueeze(0)
    print(image.size())
    return image
	
def SaveImage(output_img, output_name): 
   torchvision.utils.save_image(output_img, output_name, nrow=8, padding=2, normalize=False, range=None, scale_each=False, pad_value=0)


content_image = ImageSetup(params.content_image, params.image_size)
style_image = ImageSetup(params.style_image, params.image_size)



# Separate names for layers
VGG19_Layer_List = ['conv1_1', 'relu1_1', 'conv1_2', 'relu1_2', 'pool1', 'conv2_1', 'relu2_1', 'conv2_2', 'relu2_2', 'pool2', 'conv3_1', 'relu3_1', 'conv3_2', 'relu3_2', 'conv3_3', 'relu3_3', 'conv3_4', 'relu3_4', 'pool3', 'conv4_1', 'relu4_1', 'conv4_2', 'relu4_2', 'conv4_3', 'relu4_3', 'conv4_4', 'relu4_4', 'pool4', 'conv5_1', 'relu5_1', 'conv5_2', 'relu5_2', 'conv5_3', 'relu5_3', 'conv5_4', 'relu5_4', 'pool5', 'torch_view', 'fc6', 'relu6', 'drop6', 'fc7', 'relu7', 'drop7', 'fc8', 'prob']
VGG16_layer_List = ['conv1_1', 'relu1_1', 'conv1_2', 'relu1_2', 'pool1', 'conv2_1', 'relu2_1', 'conv2_2', 'relu2_2', 'pool2', 'conv3_1', 'relu3_1', 'conv3_2', 'relu3_2', 'conv3_3', 'relu3_3', 'pool3', 'conv4_1', 'relu4_1', 'conv4_2', 'relu4_2', 'conv4_3', 'relu4_3', 'pool4', 'conv5_1', 'relu5_1', 'conv5_2', 'relu5_2', 'conv5_3', 'relu5_3', 'pool5', 'torch_view', 'fc6', 'relu6', 'drop6', 'fc7', 'relu7', 'drop7', 'fc8', 'prob']
NIN_Layer_List = ['conv1', 'relu0', 'cccp1', 'relu1', 'cccp2', 'relu2', 'pool0', 'conv2', 'relu3', 'cccp3', 'relu5', 'cccp4', 'relu6', 'pool2', 'conv3', 'relu7', 'cccp5', 'relu8', 'cccp6', 'relu9', 'pool3', 'drop', 'conv4-1024', 'relu10', 'cccp7-1024', 'relu11', 'cccp8-1024', 'relu12', 'pool4', 'loss']

  
def ModelSetup(cnn, style_weight, content_weight, Layer_List, content_layers, style_layers, normalize_gradients):
    content_losses = []
    style_losses = []
    next_content_idx = 1
    next_style_idx = 1
    net = nn.Sequential()
	  
    i = 0
    for layer in list(cnn):
        l = int(i)
        layer_name = Layer_List[l]

        if "conv" in layer_name:
            net.add_module(layer_name, layer)
            if layer_name in content_layers:
                print("Setting up content layer " + str(i) + ": " + str(layer_name))
                norm = normalize_gradients
                loss_module = ContentLoss(content_weight, norm)
                net.add_module(layer_name, loss_module)
                content_losses.append(loss_module)
                next_content_idx = next_content_idx + 1
            if layer_name in style_layers:
                print("Setting up style layer " + str(i) + ": " + str(layer_name))
                norm = normalize_gradients
                loss_module = StyleLoss(style_weight, norm)#.type(dtype)
                net.add_module(layer_name, loss_module)
                style_losses.append(loss_module)
                next_style_idx = next_style_idx + 1

        if "relu" in layer_name:
            net.add_module(layer_name, layer)
            if layer_name in content_layers:
                print("Setting up content layer " + str(i) + ": " + str(layer_name))
                norm = normalize_gradients
                loss_module = ContentLoss(content_weight, norm)
                net.add_module(layer_name, loss_module)
                content_losses.append(loss_module)
                next_content_idx = next_content_idx + 1
            if layer_name in style_layers:
                print("Setting up style layer " + str(i) + ": " + str(layer_name))
                norm = normalize_gradients
                loss_module = StyleLoss(style_weight, norm)
                net.add_module(layer_name, loss_module)
                style_losses.append(loss_module)
                next_style_idx = next_style_idx + 1
				
        if "pool" in layer_name:
            net.add_module(layer_name, layer)  # ***
			
        i = i + 1
    cnn = None
    return net, style_losses, content_losses


model_type ='vgg19' # Default value for testing
style_weight = 1000 # Default value for testing
content_weight = 100 # Default value for testing
normalize_gradients = 'False' # Default value for testing
content_layers = ['relu4_2'] # Default value for testing
style_layers = ['relu1_1', 'relu2_1', 'relu3_1', 'relu4_1', 'relu5_1'] # Default value for testing
max_iter = 1000 # Default value for testing


cnn = None
Layer_List = []
if model_type == 'vgg19':
   cnn = models.vgg19(pretrained=True).features
   Layer_List = VGG19_Layer_List
elif model_type == 'vgg16':
   cnn = models.vgg16(pretrained=True).features
   Layer_List = VGG16_Layer_List
# Figure out what layer setup to use:	


# Build the style transfer model:
net, style_losses, content_losses = ModelSetup(cnn, style_weight, content_weight, Layer_List, content_layers, style_layers, normalize_gradients)

#print(net)
################################################
# This doesn't look right, but it works: 
norm = normalize_gradients
CL = ContentLoss(content_weight, norm)
SL = StyleLoss(style_weight, norm)
img = content_image.clone()
img = nn.Parameter(img.data)
content_image = nn.Parameter(content_image.data)
style_image = nn.Parameter(style_image.data)
################################################

print(CL)
print(SL)

# Capture content targets
for i in content_losses:
  i.mode = 'capture'
#CL.updateOutput(content_image) #This works, but then StyleLoss doesn't have it's self.output variable from ContentLoss. So GramMatrix can't run properly.
net.forward(content_image)

print("Capturing content targets")
# Capture style targets
for i in content_losses:
  i.mode = None
for j in style_losses:
  j.mode = 'capture'
  #j.blend_weight = style_blend_weights[i]
SL.updateOutput(style_image)

# Set all loss modules to loss mode
for i in content_losses:
  i.mode = 'loss'
for i in style_losses:
  i.mode = 'loss'



img = content_image.clone()
img = nn.Parameter(img.data)

y = net.forward(img)
dy = y.zero_()


num_calls = [0]
def feval(x):
  num_calls[0] += 1
  print("feval(x)")
  x.data.clamp_(0, 1)
  optimizer.zero_grad()
  for mod in content_losses:
    loss = loss + mod.loss
  for mod in style_losses:
    loss = loss + mod.loss
  maybe_print(num_calls[0], loss)
  maybe_save(num_calls[0])
  # optim.lbfgs expects a vector for gradients
  return loss, grad.view(grad.nelement())
  
 



optim_state = None
if params.optimizer == 'lbfgs':
  max_iter = params.num_iterations,
  tolerance_change = -1,
  tolerance_grad = -1,
  optim_state = {
    max_iter,
    tolerance_change,
    tolerance_grad,
  }
elif params.optimizer == 'adam':
  optim_state = {
    "lr": 1,
  }

# Run optimization.
if params.optimizer == 'lbfgs':
  print("Running optimization with L-BFGS")
  x, losses = optim.LBFGS(feval, img, optim_state)
elif params.optimizer == 'adam':
  print("Running optimization with ADAM")
  for t in xrange(params.num_iterations):
    x, losses = optim.Adam(feval, img, optim_state)


optim_state2 = {
    "max_iter": params.num_iterations,
    "tolerance_change": -1,
    "tolerance_grad": -1,
}