from?__future__?import?print_function

import?os
import?sys
import?timeit

import?numpy

import?theano
import?theano.tensor?as?T
from?theano.sandbox.rng_mrg?import?MRG_RandomStreams?as?RandomStreams

from?logistic_sgd?import?load_data
from?utils?import?tile_raster_images

try:
????import?PIL.Image?as?Image
except?ImportError:
????import?Image


class?dA（object）:
????“““Denoising?Auto-Encoder?class?（dA）

????A?denoising?autoencoders?tries?to?reconstruct?the?input?from?a?corrupted
????version?of?it?by?projecting?it?first?in?a?latent?space?and?reprojecting
????it?afterwards?back?in?the?input?space.?Please?refer?to?Vincent?et?al.2008
????for?more?details.?If?x?is?the?input?then?equation?（1）?computes?a?partially
????destroyed?version?of?x?by?means?of?a?stochastic?mapping?q_D.?Equation?（2）
????computes?the?projection?of?the?input?into?the?latent?space.?Equation?（3）
????computes?the?reconstruction?of?the?input?while?equation?（4）?computes?the
????reconstruction?error.

????..?math::

????????\tilde{x}?~?q_D（\tilde{x}|x）?????????????????????????????????????（1）

????????y?=?s（W?\tilde{x}?+?b）???????????????????????????????????????????（2）

????????x?=?s（W‘?y??+?b‘）????????????????????????????????????????????????（3）

????????L（xz）?=?-sum_{k=1}^d?[x_k?\log?z_k?+?（1-x_k）?\log（?1-z_k）]??????（4）

????“““

????def?__init__（
????????self
????????numpy_rng
????????theano_rng=None
????????input=None
????????n_visible=784
????????n_hidden=500
????????W=None
????????bhid=None
????????bvis=None
????）:
????????“““
????????Initialize?the?dA?class?by?specifying?the?number?of?visible?units?（the
????????dimension?d?of?the?input?）?the?number?of?hidden?units?（?the?dimension
????????d‘?of?the?latent?or?hidden?space?）?and?the?corruption?level.?The
????????constructor?also?receives?symbolic?variables?for?the?input?weights?and
????????bias.?Such?a?symbolic?variables?are?useful?when?for?example?the?input
????????is?the?result?of?some?computations?or?when?weights?are?shared?between
????????the?dA?and?an?MLP?layer.?When?dealing?with?SdAs?this?always?happens
????????the?dA?on?layer?2?gets?as?input?the?output?of?the?dA?on?layer?1
????????and?the?weights?of?the?dA?are?used?in?the?second?stage?of?training
????????to?construct?an?MLP.

????????:type?numpy_rng:?numpy.random.RandomState
????????:param?numpy_rng:?number?random?generator?used?to?generate?weights

????????:type?theano_rng:?theano.tensor.shared_randomstreams.RandomStreams
????????:param?theano_rng:?Theano?random?generator;?if?None?is?given?one?is
?????????????????????generated?based?on?a?seed?drawn?from?‘rng‘

????????:type?input:?theano.tensor.TensorType
????????:param?input:?a?symbolic?description?of?the?input?or?None?for
??????????????????????standalone?dA

????????:type?n_visible:?int
????????:param?n_visible:?number?of?visible?units

????????:type?n_hidden:?int
????????:param?n_hidden:??number?of?hidden?units

????????:type?W:?theano.tensor.TensorType
????????:param?W:?Theano?variable?pointing?to?a?set?o

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????目錄???????????0??2017-12-14?10:45??image-denoising-master\
?????文件????????2320??2017-12-14?10:45??image-denoising-master\README.md
?????文件???????13234??2017-12-14?10:45??image-denoising-master\dA.py
?????目錄???????????0??2017-12-14?10:45??image-denoising-master\data\
?????文件???????86860??2017-12-14?10:45??image-denoising-master\data\band1_denoised1.png
?????文件???????89019??2017-12-14?10:45??image-denoising-master\data\band1_denoised2.png
?????文件???????96255??2017-12-14?10:45??image-denoising-master\data\band1_noisy1.png
?????文件???????95355??2017-12-14?10:45??image-denoising-master\data\band1_noisy2.png
?????文件???????29920??2017-12-14?10:45??image-denoising-master\denoise_function.py
?????目錄???????????0??2017-12-14?10:45??image-denoising-master\graphs\
?????文件???????20564??2017-12-14?10:45??image-denoising-master\graphs\patches_plot.png
?????文件???????14858??2017-12-14?10:45??image-denoising-master\graphs\psnr_plot.png
?????文件???????21213??2017-12-14?10:45??image-denoising-master\graphs\variation_with_no_of_hidden_layers1.png
?????文件???????21676??2017-12-14?10:45??image-denoising-master\graphs\variation_with_size_of_hidden_layers.png
?????文件???????16224??2017-12-14?10:45??image-denoising-master\logistic_sgd.py
?????文件???????13634??2017-12-14?10:45??image-denoising-master\mlp.py
?????目錄???????????0??2017-12-14?10:45??image-denoising-master\paper\
?????文件?????2633933??2017-12-14?10:45??image-denoising-master\paper\Final_icmla_poster（1）_jp.jpg
?????文件?????1440465??2017-12-14?10:45??image-denoising-master\paper\Final_paper.pdf