import?torch
import?torch.nn.functional?as?F
from?torch.autograd?import?Variable
import?numpy?as?np
from?math?import?exp

def?gaussian（window_size?sigma）:
????gauss?=?torch.Tensor（[exp（-（x?-?window_size//2）**2/float（2*sigma**2））?for?x?in?range（window_size）]）
????return?gauss/gauss.sum（）

def?create_window（window_size?channel）:
????_1D_window?=?gaussian（window_size?1.5）.unsqueeze（1）
????_2D_window?=?_1D_window.mm（_1D_window.t（））.float（）.unsqueeze（0）.unsqueeze（0）
????window?=?Variable（_2D_window.expand（channel?1?window_size?window_size）.contiguous（））
????return?window

def?_ssim（img1?img2?window?window_size?channel?size_average?=?True）:
????mu1?=?F.conv2d（img1?window?padding?=?window_size//2?groups?=?channel）
????mu2?=?F.conv2d（img2?window?padding?=?window_size//2?groups?=?channel）

????mu1_sq?=?mu1.pow（2）
????mu2_sq?=?mu2.pow（2）
????mu1_mu2?=?mu1*mu2

????sigma1_sq?=?F.conv2d（img1*img1?window?padding?=?window_size//2?groups?=?channel）?-?mu1_sq
????sigma2_sq?=?F.conv2d（img2*img2?window?padding?=?window_size//2?groups?=?channel）?-?mu2_sq
????sigma12?=?F.conv2d（img1*img2?window?padding?=?window_size//2?groups?=?channel）?-?mu1_mu2

????C1?=?0.01**2
????C2?=?0.03**2

????ssim_map?=?（（2*mu1_mu2?+?C1）*（2*sigma12?+?C2））/（（mu1_sq?+?mu2_sq?+?C1）*（sigma1_sq?+?sigma2_sq?+?C2））

????if?size_average:
????????return?ssim_map.mean（）
????else:
????????return?ssim_map.mean（1）.mean（1）.mean（1）

class?SSIM（torch.nn.Module）:
????def?__init__（self?window_size?=?11?size_average?=?True）:
????????super（SSIM?self）.__init__（）
????????self.window_size?=?window_size
????????self.size_average?=?size_average
????????self.channel?=?3
????????self.window?=?create_window（window_size?self.channel）

????def?forward（self?img1?img2）:
????????（_?channel?_?_）?=?img1.size（）

????????if?channel?==?self.channel?and?self.window.data.type（）?==?img1.data.type（）:
????????????window?=?self.window
????????else:
????????????window?=?create_window（self.window_size?channel）
????????????
????????????if?img1.is_cuda:
????????????????window?=?window.cuda（img1.get_device（））
????????????window?=?window.type_as（img1）
????????????
????????????self.window?=?window
????????????self.channel?=?channel


????????return?_ssim（img1?img2?window?self.window_size?channel?self.size_average）

def?ssim（img1?img2?window_size?=?11?size_average?=?True）:
????（_?channel?_?_）?=?img1.size（）
????window?=?create_window（window_size?channel）
????
????if?img1.is_cuda:
????????window?=?window.cuda（img1.get_device（））
????window?=?window.type_as（img1）
????
????return?_ssim（img1?img2?window?window_size?channel?size_average）

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????目錄???????????0??2018-07-27?07:55??RESCAN-master\
?????文件????????1203??2018-07-27?07:55??RESCAN-master\.gitignore
?????文件????????1065??2018-07-27?07:55??RESCAN-master\LICENSE
?????文件????????3686??2018-07-27?07:55??RESCAN-master\README.md
?????目錄???????????0??2018-07-27?07:55??RESCAN-master\config\
?????文件????????2635??2018-07-27?07:55??RESCAN-master\config\cal_ssim.py
?????文件??????????96??2018-07-27?07:55??RESCAN-master\config\clean.sh
?????文件????????4336??2018-07-27?07:55??RESCAN-master\config\dataset.py
?????文件????????7086??2018-07-27?07:55??RESCAN-master\config\main.py
?????文件????????6194??2018-07-27?07:55??RESCAN-master\config\model.py
?????文件?????????742??2018-07-27?07:55??RESCAN-master\config\settings.py
?????文件????????2605??2018-07-27?07:55??RESCAN-master\config\show.py
?????文件?????????233??2018-07-27?07:55??RESCAN-master\config\tensorboard.sh
?????目錄???????????0??2018-07-27?07:55??RESCAN-master\docs\
?????文件???????????1??2018-07-27?07:55??RESCAN-master\docs\index.html
?????文件?????????180??2018-07-27?07:55??RESCAN-master\explore.sh