Presentation 2018-03-18
Learning Convolutional Autoencoders Using a Loss Function Based on Spatial Frequencies and Colors
Naoyuki Ichimura,
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Abstract(in Japanese) (See Japanese page)
Abstract(in English) This paper presents a learning method for convolutional autoencoders (CAEs) for extracting features from images. CAEs can be obtained by utilizing convolutional neural networks to learn an approximation to the identity function in an unsupervised manner. The loss function based on the pixel loss (PL) that is computed from the mean squared errors between the pixel values of original images and reconstructed images is the common choice for learning. However, using the loss function leads to blurred reconstructed images and requires a large number of epochs to reproduce colors. A method for learning CAEs using a loss function based on spatial frequencies and colors is proposed to mitigate the problems. The blurs in reconstructed images show lack of high spatial frequency components. In order to evaluate the lack of components, a convolutional layer with a Laplacian filter bank as weights is added to CAEs and the mean squared error of a subband (Spatial Frequency Loss:SFL) is obtained from the output of each filter. The mean squared error of a chromatic component (Chromatic Loss:CL) is introduced as well to evaluate color reproduction by addition a convolutional layer by which chromatic components are separated from a luminance component. The learning is performed using a loss function based on the SFL and CL. Empirical evaluation demonstrates that using the SFL reduces the blurs and using the CL facilitates the reproduction of colors.
Keyword(in Japanese) (See Japanese page)
Keyword(in English) Convolutional autoencoders / Unsupervised learning / Loss function / Spatial frequency / Color
Paper # BioX2017-36,PRMU2017-172
Date of Issue 2018-03-11 (BioX, PRMU)

Conference Information
Committee PRMU / BioX
Conference Date 2018/3/18(2days)
Place (in Japanese) (See Japanese page)
Place (in English)
Topics (in Japanese) (See Japanese page)
Topics (in English)
Chair Shinichi Sato(NII) / Kazuhiko Sumi(AGU)
Vice Chair Hironobu Fujiyoshi(Chubu Univ.) / Yoshihisa Ijiri(Omron) / Hiroshi Takano(Toyama Pref. Univ.) / Hitoshi Imaoka(NEC)
Secretary Hironobu Fujiyoshi(AIST) / Yoshihisa Ijiri(NAIST) / Hiroshi Takano(Shizuoka Univ.) / Hitoshi Imaoka(Fujitsu Labs.)
Assistant Masato Ishii(NEC) / Yusuke Sugano(Osaka Univ.) / Masatsugu Ichino(Univ. of Electro-Comm.) / Naoyuki Takada(Secom) / Norihiro Okui(KDDI Research)

Paper Information
Registration To Technical Committee on Pattern Recognition and Media Understanding / Technical Committee on Biometrics
Language JPN
Title (in Japanese) (See Japanese page)
Sub Title (in Japanese) (See Japanese page)
Title (in English) Learning Convolutional Autoencoders Using a Loss Function Based on Spatial Frequencies and Colors
Sub Title (in English)
Keyword(1) Convolutional autoencoders
Keyword(2) Unsupervised learning
Keyword(3) Loss function
Keyword(4) Spatial frequency
Keyword(5) Color
1st Author's Name Naoyuki Ichimura
1st Author's Affiliation National Institute of Advanced Industrial Science and Technology(AIST)
Date 2018-03-18
Paper # BioX2017-36,PRMU2017-172
Volume (vol) vol.117
Number (no) BioX-513,PRMU-514
Page pp.pp.1-6(BioX), pp.1-6(PRMU),
#Pages 6
Date of Issue 2018-03-11 (BioX, PRMU)