File size: 20,838 Bytes
1b2a9b1
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
"""
07-21
StyleLoss to encourage style statistics to be consistent within each cluster.
"""
import torch
import torchvision
import torch.nn as nn
import torch.nn.functional as F

# VGG architecter, used for the perceptual loss using a pretrained VGG network
class VGG19(torch.nn.Module):
    def __init__(self, requires_grad=False, device = torch.device(f'cuda:0')):
        super().__init__()
        vgg_pretrained_features = torchvision.models.vgg19(pretrained=True).features
        self.slice1 = torch.nn.Sequential()
        self.slice2 = torch.nn.Sequential()
        self.slice3 = torch.nn.Sequential()
        self.slice4 = torch.nn.Sequential()
        self.slice5 = torch.nn.Sequential()
        for x in range(2):
            self.slice1.add_module(str(x), vgg_pretrained_features[x])
        for x in range(2, 7):
            self.slice2.add_module(str(x), vgg_pretrained_features[x])
        for x in range(7, 12):
            self.slice3.add_module(str(x), vgg_pretrained_features[x])
        for x in range(12, 21):
            self.slice4.add_module(str(x), vgg_pretrained_features[x])
        for x in range(21, 30):
            self.slice5.add_module(str(x), vgg_pretrained_features[x])
        if not requires_grad:
            for param in self.parameters():
                param.requires_grad = False

        cnn_normalization_mean = torch.tensor([0.485, 0.456, 0.406]).to(device)
        cnn_normalization_std = torch.tensor([0.229, 0.224, 0.225]).to(device)
        self.normalization = Normalization(cnn_normalization_mean, cnn_normalization_std)

    def forward(self, X):
        #X = self.normalization(X)
        h_relu1 = self.slice1(X)
        h_relu2 = self.slice2(h_relu1)
        h_relu3 = self.slice3(h_relu2)
        h_relu4 = self.slice4(h_relu3)
        h_relu5 = self.slice5(h_relu4)
        out = [h_relu1, h_relu2, h_relu3, h_relu4, h_relu5]
        return out

# create a module to normalize input image so we can easily put it in a
# nn.Sequential
class Normalization(nn.Module):
    def __init__(self, mean, std):
        super(Normalization, self).__init__()
        # .view the mean and std to make them [C x 1 x 1] so that they can
        # directly work with image Tensor of shape [B x C x H x W].
        # B is batch size. C is number of channels. H is height and W is width.
        self.mean = torch.tensor(mean).view(-1, 1, 1)
        self.std = torch.tensor(std).view(-1, 1, 1)

    def forward(self, img):
        # normalize img
        return (img - self.mean) / self.std

class GramMatrix(nn.Module):
    def forward(self,input):
        b, c, h, w = input.size()
        f = input.view(b,c,h*w) # bxcx(hxw)
        # torch.bmm(batch1, batch2, out=None)   #
        # batch1: bxmxp, batch2: bxpxn -> bxmxn #
        G = torch.bmm(f,f.transpose(1,2)) # f: bxcx(hxw), f.transpose: bx(hxw)xc -> bxcxc
        return G.div_(c*h*w)

class StyleLoss(nn.Module):
    """
    Version 1. Compare mean and variance cluster-wise.
    """
    def __init__(self, style_layers = 'relu3, relu4, relu5', device = torch.device(f'cuda:0'), style_mode = 'gram'):
        super().__init__()
        self.vgg = VGG19()
        self.style_layers = []
        for style_layer in style_layers.split(','):
            self.style_layers.append(int(style_layer[-1]) - 1)
        self.style_mode = style_mode

        cnn_normalization_mean = torch.tensor([0.485, 0.456, 0.406]).to(device)
        cnn_normalization_std = torch.tensor([0.229, 0.224, 0.225]).to(device)
        self.normalization = Normalization(cnn_normalization_mean, cnn_normalization_std)

    def forward(self, pred, gt):
        """
        INPUTS:
         - pred: (B, 3, H, W)
         - gt: (B, 3, H, W)
         - seg: (B, H, W)
        """
        # extract features for images
        B, _, H, W = pred.shape
        pred = self.normalization(pred)
        gt = self.normalization(gt)
        pred_feats = self.vgg(pred)
        gt_feats = self.vgg(gt)
        loss = 0
        for style_layer in self.style_layers:
            pred_feat = pred_feats[style_layer]
            gt_feat = gt_feats[style_layer]
            pred_gram = GramMatrix()(pred_feat)
            gt_gram = GramMatrix()(gt_feat)
            loss += torch.sum((pred_gram - gt_gram) ** 2) / B
        return loss

class styleLossMask(nn.Module):
    """
    Version 1. Compare mean and variance cluster-wise.
    """
    def __init__(self, style_layers = 'relu3, relu4, relu5', device = torch.device(f'cuda:0'), style_mode = 'gram'):
        super().__init__()
        self.vgg = VGG19()
        self.style_layers = []
        for style_layer in style_layers.split(','):
            self.style_layers.append(int(style_layer[-1]) - 1)
        self.style_mode = style_mode

        #cnn_normalization_mean = torch.tensor([0.485, 0.456, 0.406]).to(device)
        #cnn_normalization_std = torch.tensor([0.229, 0.224, 0.225]).to(device)
        #self.normalization = Normalization(cnn_normalization_mean, cnn_normalization_std)

    def forward(self, input, target, mask):
        B, _, H, W = input.shape
        #pred = self.normalization(input)
        #target = self.normalization(target)
        pred_feats = self.vgg(input)
        gt_feats = self.vgg(target)


        loss = 0
        mb, mc, mh, mw = mask.shape
        for style_layer in self.style_layers:
            pred_feat = pred_feats[style_layer]
            gt_feat = gt_feats[style_layer]

            ib,ic,ih,iw = pred_feat.size()
            iF = pred_feat.view(ib,ic,-1)
            tb,tc,th,tw = gt_feat.size()
            tF = gt_feat.view(tb,tc,-1)

            for i in range(mb):
                # resize mask to have the same size of the feature
                maski = F.interpolate(mask[i:i+1], size = (ih, iw), mode = 'nearest')
                mask_flat_i = maski.view(mc, -1)

                maskt = F.interpolate(mask[i:i+1], size = (th, tw), mode = 'nearest')
                mask_flat_t = maskt.view(mc, -1)
                for j in range(mc):
                    # get features for each part
                    idx = torch.nonzero(mask_flat_i[j]).squeeze()
                    if len(idx.shape) == 0 or idx.shape[0] == 0:
                        continue
                    ipart = torch.index_select(iF, 2, idx)

                    idx = torch.nonzero(mask_flat_t[j]).squeeze()
                    if len(idx.shape) == 0 or idx.shape[0] == 0:
                        continue
                    tpart = torch.index_select(tF, 2, idx)

                    iMean = torch.mean(ipart,dim=2)
                    iGram = torch.bmm(ipart, ipart.transpose(1,2)).div_(ic*ih*iw) # f: bxcx(hxw), f.transpose: bx(hxw)xc -> bxcxc

                    tMean = torch.mean(tpart,dim=2)
                    tGram = torch.bmm(tpart, tpart.transpose(1,2)).div_(tc*th*tw) # f: bxcx(hxw), f.transpose: bx(hxw)xc -> bxcxc

                    loss_j = nn.MSELoss()(iMean,tMean) + nn.MSELoss()(iGram,tGram)
                    loss += loss_j
        return loss/tb

# Perceptual loss that uses a pretrained VGG network
class VGGLoss(nn.Module):
    def __init__(self, weights = [1.0 / 32, 1.0 / 16, 1.0 / 8, 1.0 / 4, 1.0], device = torch.device(f'cuda:0')):
        super(VGGLoss, self).__init__()
        self.vgg = VGG19(device = device)
        self.criterion = nn.L1Loss()
        self.weights = weights

    def forward(self, x, y):
        x_vgg, y_vgg = self.vgg(x), self.vgg(y)
        loss = 0
        for i in range(len(x_vgg)):
            loss += self.weights[i] * self.criterion(x_vgg[i], y_vgg[i].detach())
        return loss

class styleLossMaskv2(nn.Module):
    def __init__(self, style_layers = 'relu3, relu4, relu5', device = torch.device(f'cuda:0')):
        super().__init__()
        self.vgg = VGG19(device = device)
        self.style_layers = []
        for style_layer in style_layers.split(','):
            self.style_layers.append(int(style_layer[-1]) - 1)
        cnn_normalization_mean = torch.tensor([0.485, 0.456, 0.406]).to(device)
        cnn_normalization_std = torch.tensor([0.229, 0.224, 0.225]).to(device)
        self.normalization = Normalization(cnn_normalization_mean, cnn_normalization_std)

    def forward(self, input, target, mask_input, mask_target):
        B, _, H, W = input.shape
        input = self.normalization(input)
        target = self.normalization(target)
        pred_feats = self.vgg(input)
        gt_feats = self.vgg(target)


        loss = 0
        mb, mc, mh, mw = mask_input.shape
        for style_layer in self.style_layers:
            pred_feat = pred_feats[style_layer]
            gt_feat = gt_feats[style_layer]

            ib,ic,ih,iw = pred_feat.size()
            iF = pred_feat.view(ib,ic,-1)
            tb,tc,th,tw = gt_feat.size()
            tF = gt_feat.view(tb,tc,-1)

            for i in range(mb):
                # resize mask to have the same size of the feature
                maski = F.interpolate(mask_input[i:i+1], size = (ih, iw), mode = 'nearest')
                mask_flat_i = maski.view(mc, -1)

                maskt = F.interpolate(mask_target[i:i+1], size = (th, tw), mode = 'nearest')
                mask_flat_t = maskt.view(mc, -1)
                for j in range(mc):
                    # get features for each part
                    idx = torch.nonzero(mask_flat_i[j]).squeeze()
                    if len(idx.shape) == 0 or idx.shape[0] == 0:
                        continue
                    ipart = torch.index_select(iF[i:i+1], 2, idx)

                    idx = torch.nonzero(mask_flat_t[j]).squeeze()
                    if len(idx.shape) == 0 or idx.shape[0] == 0:
                        continue
                    tpart = torch.index_select(tF[i:i+1], 2, idx)

                    iGram = torch.bmm(ipart, ipart.transpose(1,2)).div_(ipart.shape[1] * ipart.shape[2]) # f: bxcx(hxw), f.transpose: bx(hxw)xc -> bxcxc
                    tGram = torch.bmm(tpart, tpart.transpose(1,2)).div_(tpart.shape[1] * tpart.shape[2]) # f: bxcx(hxw), f.transpose: bx(hxw)xc -> bxcxc

                    loss += torch.sum((iGram - tGram) ** 2)
        return loss/tb

class styleLossMaskv3(nn.Module):
    def __init__(self, style_layers = 'relu1, relu2, relu3, relu4, relu5', device = torch.device(f'cuda:0')):
        super().__init__()
        self.vgg = VGG19(device = device)
        self.style_layers = []
        for style_layer in style_layers.split(','):
            self.style_layers.append(int(style_layer[-1]) - 1)
        cnn_normalization_mean = torch.tensor([0.485, 0.456, 0.406]).to(device)
        cnn_normalization_std = torch.tensor([0.229, 0.224, 0.225]).to(device)
        self.normalization = Normalization(cnn_normalization_mean, cnn_normalization_std)

    def forward_img_img(self, input, target, mask_input, mask_target):
        B, _, H, W = input.shape
        input = self.normalization(input)
        target = self.normalization(target)
        pred_feats = self.vgg(input)
        gt_feats = self.vgg(target)

        loss = 0
        mb, mc, mh, mw = mask_input.shape
        for style_layer in self.style_layers:
            pred_feat = pred_feats[style_layer]
            gt_feat = gt_feats[style_layer]

            ib,ic,ih,iw = pred_feat.size()
            iF = pred_feat.view(ib,ic,-1)
            tb,tc,th,tw = gt_feat.size()
            tF = gt_feat.view(tb,tc,-1)

            for i in range(mb):
                # resize mask to have the same size of the feature
                maski = F.interpolate(mask_input[i:i+1], size = (ih, iw), mode = 'nearest')
                mask_flat_i = maski.view(mc, -1)

                maskt = F.interpolate(mask_target[i:i+1], size = (th, tw), mode = 'nearest')
                mask_flat_t = maskt.view(mc, -1)
                for j in range(mc):
                    # get features for each part
                    idx = torch.nonzero(mask_flat_i[j]).squeeze()
                    if len(idx.shape) == 0 or idx.shape[0] == 0:
                        continue
                    ipart = torch.index_select(iF[i:i+1], 2, idx)

                    idx = torch.nonzero(mask_flat_t[j]).squeeze()
                    if len(idx.shape) == 0 or idx.shape[0] == 0:
                        continue
                    tpart = torch.index_select(tF[i:i+1], 2, idx)

                    iGram = torch.bmm(ipart, ipart.transpose(1,2)).div_(ipart.shape[1] * ipart.shape[2]) # f: bxcx(hxw), f.transpose: bx(hxw)xc -> bxcxc
                    tGram = torch.bmm(tpart, tpart.transpose(1,2)).div_(tpart.shape[1] * tpart.shape[2]) # f: bxcx(hxw), f.transpose: bx(hxw)xc -> bxcxc

                    #loss += torch.sum((iGram - tGram) ** 2)
                    loss += F.mse_loss(iGram, tGram)
        #return loss/tb
        return loss * 100000 / tb

    def forward_patch_img(self, input, target, mask_target):
        input = self.normalization(input)
        target = self.normalization(target)
        pred_feats = self.vgg(input)
        gt_feats = self.vgg(target)
        patch_num = input.shape[0] // target.shape[0]

        loss = 0
        for style_layer in self.style_layers:
            pred_feat = pred_feats[style_layer]
            gt_feat = gt_feats[style_layer]

            ib,ic,ih,iw = pred_feat.size()
            iF = pred_feat.view(ib,ic,-1)
            tb,tc,th,tw = gt_feat.size()
            tF = gt_feat.view(tb,tc,-1)

            for i in range(tb):
                # resize mask to have the same size of the feature
                maskt = F.interpolate(mask_target[i:i+1], size = (th, tw), mode = 'nearest')
                mask_flat_t = maskt.view(-1)

                idx = torch.nonzero(mask_flat_t).squeeze()
                if len(idx.shape) == 0 or idx.shape[0] == 0:
                    continue
                tpart = torch.index_select(tF[i:i+1], 2, idx)
                tGram = torch.bmm(tpart, tpart.transpose(1,2)).div_(tpart.shape[1] * tpart.shape[2]) # f: bxcx(hxw), f.transpose: bx(hxw)xc -> bxcxc

                ipart = iF[i * patch_num: (i + 1) * patch_num]
                iGram = torch.bmm(ipart, ipart.transpose(1,2)).div_(ipart.shape[1] * ipart.shape[2]) # f: bxcx(hxw), f.transpose: bx(hxw)xc -> bxcxc

                #loss += torch.sum((iGram - tGram.repeat(patch_num, 1, 1)) ** 2)
                loss += F.mse_loss(iGram, tGram.repeat(patch_num, 1, 1))
        return loss/ib * 100000

class KLDLoss(nn.Module):
    def forward(self, mu, logvar):
        return -0.5 * torch.sum(1 + logvar - mu.pow(2) - logvar.exp())

class LPIPSorGramMatch(nn.Module):
    """
    Version 1. Compare mean and variance cluster-wise.
    """
    def __init__(self, style_layers = 'relu3, relu4, relu5', device = torch.device(f'cuda:0'),
                 weights = [1.0 / 32, 1.0 / 16, 1.0 / 8, 1.0 / 4, 1.0],):
        super().__init__()
        self.vgg = VGG19(device = device)
        self.style_layers = []
        for style_layer in style_layers.split(','):
            self.style_layers.append(int(style_layer[-1]) - 1)

        cnn_normalization_mean = torch.tensor([0.485, 0.456, 0.406]).to(device)
        cnn_normalization_std = torch.tensor([0.229, 0.224, 0.225]).to(device)
        self.normalization = Normalization(cnn_normalization_mean, cnn_normalization_std)

        self.criterion = nn.L1Loss()
        self.weights = weights

    def forward(self, pred, gt, mode = 'lpips'):
        """
        INPUTS:
         - pred: (B, 3, H, W)
         - gt: (B, 3, H, W)
         - seg: (B, H, W)
        """
        # extract features for images
        B, _, H, W = pred.shape
        pred = self.normalization(pred)
        gt = self.normalization(gt)
        pred_feats = self.vgg(pred)
        gt_feats = self.vgg(gt)

        if mode == 'lpips':
            lpips_loss = 0
            for i in range(len(pred_feats)):
                lpips_loss += self.weights[i] * self.criterion(pred_feats[i], gt_feats[i].detach())
            return lpips_loss
        elif mode == 'gram_match':
            gram_match_loss = 0
            for style_layer in self.style_layers:
                pred_feat = pred_feats[style_layer]
                gt_feat = gt_feats[style_layer]
                pred_gram = GramMatrix()(pred_feat)
                gt_gram = GramMatrix()(gt_feat)
                gram_match_loss += torch.sum((pred_gram - gt_gram) ** 2) / B
            return gram_match_loss
        else:
            raise ValueError("Only computes lpips or gram match loss.")

class styleLossMaskv4(nn.Module):
    def __init__(self, style_layers = 'relu3, relu4, relu5', device = torch.device(f'cuda:0')):
        super().__init__()
        self.vgg = VGG19(device = device)
        self.style_layers = []
        for style_layer in style_layers.split(','):
            self.style_layers.append(int(style_layer[-1]) - 1)
        cnn_normalization_mean = torch.tensor([0.485, 0.456, 0.406]).to(device)
        cnn_normalization_std = torch.tensor([0.229, 0.224, 0.225]).to(device)
        self.normalization = Normalization(cnn_normalization_mean, cnn_normalization_std)

    def forward_img_img(self, input, target, mask_input, mask_target):
        B, _, H, W = input.shape
        input = self.normalization(input)
        target = self.normalization(target)
        pred_feats = self.vgg(input)
        gt_feats = self.vgg(target)


        loss = 0
        mb, mc, mh, mw = mask_input.shape
        for style_layer in self.style_layers:
            pred_feat = pred_feats[style_layer]
            gt_feat = gt_feats[style_layer]

            ib,ic,ih,iw = pred_feat.size()
            iF = pred_feat.view(ib,ic,-1)
            tb,tc,th,tw = gt_feat.size()
            tF = gt_feat.view(tb,tc,-1)

            for i in range(mb):
                # resize mask to have the same size of the feature
                maski = F.interpolate(mask_input[i:i+1], size = (ih, iw), mode = 'nearest')
                mask_flat_i = maski.view(mc, -1)

                maskt = F.interpolate(mask_target[i:i+1], size = (th, tw), mode = 'nearest')
                mask_flat_t = maskt.view(mc, -1)
                for j in range(mc):
                    # get features for each part
                    idx = torch.nonzero(mask_flat_i[j]).squeeze()
                    if len(idx.shape) == 0 or idx.shape[0] == 0:
                        continue
                    ipart = torch.index_select(iF[i:i+1], 2, idx)

                    idx = torch.nonzero(mask_flat_t[j]).squeeze()
                    if len(idx.shape) == 0 or idx.shape[0] == 0:
                        continue
                    tpart = torch.index_select(tF[i:i+1], 2, idx)

                    iGram = torch.bmm(ipart, ipart.transpose(1,2)).div_(ipart.shape[1] * ipart.shape[2]) # f: bxcx(hxw), f.transpose: bx(hxw)xc -> bxcxc
                    iMean = torch.mean(ipart, dim=2)
                    tGram = torch.bmm(tpart, tpart.transpose(1,2)).div_(tpart.shape[1] * tpart.shape[2]) # f: bxcx(hxw), f.transpose: bx(hxw)xc -> bxcxc
                    tMean = torch.mean(tpart, dim=2)

                    loss += torch.sum((iGram - tGram) ** 2) + torch.sum((iMean - tMean) ** 2) * 0.01
        return loss/tb

    def forward_patch_img(self, input, target, mask_target):
        input = self.normalization(input)
        target = self.normalization(target)
        pred_feats = self.vgg(input)
        gt_feats = self.vgg(target)
        patch_num = input.shape[0] // target.shape[0]

        loss = 0
        for style_layer in self.style_layers:
            pred_feat = pred_feats[style_layer]
            gt_feat = gt_feats[style_layer]

            ib,ic,ih,iw = pred_feat.size()
            iF = pred_feat.view(ib,ic,-1)
            tb,tc,th,tw = gt_feat.size()
            tF = gt_feat.view(tb,tc,-1)

            for i in range(tb):
                # resize mask to have the same size of the feature
                maskt = F.interpolate(mask_target[i:i+1], size = (th, tw), mode = 'nearest')
                mask_flat_t = maskt.view(-1)

                idx = torch.nonzero(mask_flat_t).squeeze()
                if len(idx.shape) == 0 or idx.shape[0] == 0:
                    continue
                tpart = torch.index_select(tF[i:i+1], 2, idx)
                tGram = torch.bmm(tpart, tpart.transpose(1,2)).div_(tpart.shape[1] * tpart.shape[2]) # f: bxcx(hxw), f.transpose: bx(hxw)xc -> bxcxc
                tMean = torch.mean(tpart, dim=2)

                ipart = iF[i * patch_num: (i + 1) * patch_num]
                iMean = torch.mean(ipart, dim=2)
                iGram = torch.bmm(ipart, ipart.transpose(1,2)).div_(ipart.shape[1] * ipart.shape[2]) # f: bxcx(hxw), f.transpose: bx(hxw)xc -> bxcxc

                loss += torch.sum((iGram - tGram.repeat(patch_num, 1, 1)) ** 2)
                loss += torch.sum((iMean - tMean.repeat(patch_num, 1)) ** 2) * 0.01
        return loss/ib