
\documentclass[runningheads]{llncs}
\usepackage{graphicx}
\usepackage{amsmath,amssymb} % define this before the line numbering.
\usepackage{color}
\usepackage{subfigure}
\usepackage{multirow}

%===========================================================
\begin{document}
\pagestyle{headings}
\mainmatter

\def\ACCV20SubNumber{341}  % Insert your submission number here


\title{Supplementary Materials to ``Degradation Model Learning for Real-World Single Image Super-resolution''} % Replace with your title

\titlerunning{Degradation Model Learning for Real-World SISR}
% If the paper title is too long for the running head, you can set
% an abbreviated paper title here
%
\author{Jin Xiao\inst{1} \and % \inst{1}
Hongwei Yong\inst{1,2} \and
Lei Zhang\inst{1,2}\thanks{Corresponding author. This work is supported by the Hong Kong RGC GRF grant (PolyU 152216/18E).}}
%
\authorrunning{J. Xiao et al.}
% First names are abbreviated in the running head.
% If there are more than two authors, 'et al.' is used.
%
\institute{Department of Computing, The Hong Kong Polytechnic University, Hong Kong \and DAMO Academy, Alibaba Group, Hangzhou, China \\
\email{\{csjxiao, cshyong, cslzhang\}@comp.polyu.edu.hk}}
% \url{http://www.springer.com/gp/computer-science/lncs} \and
% ABC Institute, Rupert-Karls-University Heidelberg, Heidelberg, Germany\\
% \email{\{abc,lncs\}@uni-heidelberg.de}}


\maketitle


\noindent{In this supplementary file, we provide the following materials:}
\begin{enumerate}
\item Visual comparison of competing SISR models on the RealSR \cite{realsr} dataset;

\item Visual comparison of competing SISR models on the SR-RGB \cite{LearnToZoom} dataset.
\end{enumerate}
We compare the SISR results of VDSR/RCAN models trained on different training datasets, i.e., only RealSR \cite{realsr}, only Syn-DSGAN \cite{dsgan}, only Syn-DML, the combination of RealSR and Syn-DSGAN, and the combination of RealSR and Syn-DML (please refer to Section 4.4 in the main paper).

% We compare the SISR performance by VDSR/RCAN models trained on different training datasets, i.e., only RealSR \cite{realsr}, only Syn-DSGAN \cite{dsgan}, only Syn-DML dataset, the combination of RealSR and Syn-DSGAN, and the combination of RealSR and Syn-DML dataset (please refer to Section 4.4 in the main paper).
% This supplementary file provides the visual comparison of competing SISR methods on the real-world SR-RGB \cite{LearnToZoom} dataset (please refer to Section 4.4 in the main paper).
%
\section{\normalsize Visual comparison of competing SISR models on the RealSR \cite{realsr} dataset.}
Fig. \ref{fig:supp_realsr_2} $\sim$ Fig. \ref{fig:supp_realsr_4} show the super-resolved images from the RealSR \cite{realsr} dataset with zooming factors $\times2$, $\times3$ and $\times4$, respectively. One can see that models trained on Syn-DSGAN produce noticeable artifacts. Models trained on Syn-DML can effectively recover more image details with more pleasant perceptual quality than those trained using only the RealSR dataset. The models trained on RealSR+Syn-DML achieve the best visual quality.

% In Fig. \ref{fig:supp_realsr_2} to Fig. \ref{fig:supp_4} we visualized the super-resolved HR images on the RealSR \cite{realsr} dataset of zooming factors $\times2$, $\times3$, $\times4$ respectively.
% One can see that models trained on Syn-DSGAN produce noticeable artifacts.
% Models trained on Syn-DML can effectively recover more image details with more pleasant perceptual quality than those trained using only the RealSR dataset.
% In particular, the models trained on RealSR+Syn-DML achieve the best visual quality.


\section{\normalsize Visual comparison of competing SISR models on the SR-RGB \cite{LearnToZoom} dataset.}

Fig. \ref{fig:supp_2} $\sim$ Fig. \ref{fig:supp_4} show the super-resolved images from the SR-RGB \cite{LearnToZoom} dataset with zooming factors $\times2$, $\times3$ and $\times4$, respectively. One can observe that models trained on the RealSR dataset can only moderately recover some details. Models trained on Syn-DSGAN produce severe artifacts. Benefitting from the enlarged realistic training data, SISR models trained on Syn-DML dataset can produce visually pleasing results with more fine-grained details. And the models trained on combined RealSR+Syn-DML deliver the best perceptual quality of super-resolved HR images. This demonstrates that our proposed degradation model learning method can effectively improve the generalization performance of SISR models to real-world applications.


% In Fig. \ref{fig:supp_2} to Fig. \ref{fig:supp_4} we visualized the super-resolved HR images on the SR-RGB \cite{LearnToZoom} dataset of zooming factors $\times2$, $\times3$ and $\times4$ respectively. One can observe that models trained on RealSR dataset can only moderately recover some details. Models trained on Syn-DSGAN produce severe artifacts. Benefitting from the enlarged realistic training data, SISR models trained on Syn-DML dataset can produce visually pleasing results with more fine-grained details. And the models trained on combined RealSR+Syn-DML deliver the best perceptual quality of super-resolved HR images. These demonstrate that our proposed degradation learning based model can effectively improve the generalization performance of SISR models to real-world applications.





%------------------------------------------------------------------------------
\begin{figure*}[!tp]
%\vspace{-5mm}
\scriptsize
\centering
\setlength{\tabcolsep}{0.3mm}{
\begin{tabular}{cc}
%------------------------------------------------------
\begin{tabular}{c}
\includegraphics[width=0.132\linewidth,height=0.120\linewidth]{images//supp//realsrx2//im1.JPG}\\
\end{tabular}
\begin{tabular}{ccccccc}
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Nikon_002_LR2_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Nikon_002_LR2_vdsr_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Nikon_002_LR2_dsgan_vdsr_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Nikon_002_LR2_r_k15n8_vdsr_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Nikon_002_LR2_dsgan_vdsr_syn_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Nikon_002_LR2_r_k15n8_vdsr_syn_real_cr.png}
& \rotatebox[origin=rb]{-90}{VDSR \quad}
\\
\multirow{2}{*}{LR patch} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\\
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Nikon_002_HR_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Nikon_002_LR2_rcan_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Nikon_002_LR2_dsgan_rcan_syn_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Nikon_002_LR2_r_k15n8_rcan_syn_cr.png}&
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Nikon_002_LR2_dsgan_vdsr_syn_real_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Nikon_002_LR2_r_k15n8_rcan_syn_real_cr.png}
& \rotatebox[origin=rb]{-90}{RCAN \quad}
\\
\multirow{2}{*}{\shortstack{Reference \\GT patch}} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\end{tabular}
%----------------------------------------------------------------------------------------\\
\\
\begin{tabular}{c}
\includegraphics[width=0.132\linewidth,height=0.120\linewidth]{images//supp//realsrx2//im2.JPG}\\
\end{tabular}
\begin{tabular}{ccccccc}
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Nikon_001_LR2_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Nikon_001_LR2_vdsr_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Nikon_001_LR2_dsgan_vdsr_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Nikon_001_LR2_r_k15n8_vdsr_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Nikon_001_LR2_dsgan_vdsr_syn_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Nikon_001_LR2_r_k15n8_vdsr_syn_real_cr.png}
& \rotatebox[origin=rb]{-90}{VDSR \quad}
\\
\multirow{2}{*}{LR patch} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\\
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Nikon_001_HR_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Nikon_001_LR2_rcan_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Nikon_001_LR2_dsgan_rcan_syn_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Nikon_001_LR2_r_k15n8_rcan_syn_cr.png}&
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Nikon_001_LR2_dsgan_vdsr_syn_real_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Nikon_001_LR2_r_k15n8_vdsr_syn_cr.png}
& \rotatebox[origin=rb]{-90}{RCAN \quad}
\\
\multirow{2}{*}{\shortstack{Reference \\GT patch}} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\end{tabular}
%-----------------------------------------------------------------------------------------------
\\
\\
\begin{tabular}{c}
\includegraphics[width=0.132\linewidth,height=0.120\linewidth]{images//supp//realsrx2//im3.JPG}\\
\end{tabular}
\begin{tabular}{ccccccc}
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Canon_006_LR2_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Canon_006_LR2_vdsr_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Canon_006_LR2_dsgan_vdsr_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Canon_006_LR2_r_k15n8_vdsr_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Canon_006_LR2_dsgan_vdsr_syn_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Canon_006_LR2_r_k15n8_vdsr_syn_real_cr.png}
& \rotatebox[origin=rb]{-90}{VDSR \quad}
\\
\multirow{2}{*}{LR patch} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\\
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Canon_006_HR_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Canon_006_LR2_rcan_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Canon_006_LR2_dsgan_rcan_syn_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Canon_006_LR2_r_k15n8_rcan_syn_cr.png}&
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Canon_006_LR2_dsgan_vdsr_syn_real_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx2//Canon_006_LR2_r_k15n8_vdsr_syn_cr.png}
& \rotatebox[origin=rb]{-90}{RCAN \quad}
\\
\multirow{2}{*}{\shortstack{Reference \\GT patch}} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\end{tabular}
%----------------------------------------------------------------------------------------
\end{tabular}}
\caption{Visual comparison of the competing SISR models on RealSR \cite{realsr} dataset with zooming factor $\times$2. The first and second rows of each example are super-resolved patches by VDSR and RCAN networks, respectively, which are trained using different training data.}
\label{fig:supp_realsr_2}
\end{figure*}
%----------------------------------------------------------------------------------------











%------------------------------------------------------------------------------
\begin{figure*}[!tp]
%\vspace{-5mm}
\scriptsize
\centering
\setlength{\tabcolsep}{0.3mm}{
\begin{tabular}{cc}
%------------------------------------------------------
\begin{tabular}{c}
\includegraphics[width=0.132\linewidth,height=0.120\linewidth]{images//supp//realsrx3//im.JPG}\\
\end{tabular}
\begin{tabular}{ccccccc}
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Nikon_048_LR3_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Nikon_048_LR3_vdsr_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Nikon_048_LR3_dsgan_vdsr_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Nikon_048_LR3_dml_vdsr_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Nikon_048_LR3_dsgan_vdsr_syn_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Nikon_048_LR3_dml_vdsr_syn_real_cr.png}
& \rotatebox[origin=rb]{-90}{VDSR \quad}
\\
\multirow{2}{*}{LR patch} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\\
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Nikon_048_HR_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Nikon_048_LR3_rcan_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Nikon_048_LR3_dsgan_rcan_syn_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Nikon_048_LR3_dml_rcan_syn_cr.png}&
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Nikon_048_LR3_dsgan_vdsr_syn_real_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Nikon_048_LR3_dml_rcan_syn_real_cr.png}
& \rotatebox[origin=rb]{-90}{RCAN \quad}
\\
\multirow{2}{*}{\shortstack{Reference \\GT patch}} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\end{tabular}
%----------------------------------------------------------------------------------------
\\
\\
\begin{tabular}{c}
\includegraphics[width=0.132\linewidth,height=0.120\linewidth]{images//supp//realsrx3//im2.JPG}\\
\end{tabular}
\begin{tabular}{ccccccc}
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Canon_020_LR3_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Canon_020_LR3_vdsr_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Canon_020_LR3_dsgan_vdsr_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Canon_020_LR3_dml_vdsr_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Canon_020_LR3_dsgan_vdsr_syn_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Canon_020_LR3_dml_vdsr_syn_real_cr.png}
& \rotatebox[origin=rb]{-90}{VDSR \quad}
\\
\multirow{2}{*}{LR patch} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\\
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Canon_020_HR_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Canon_020_LR3_rcan_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Canon_020_LR3_dsgan_rcan_syn_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Canon_020_LR3_dml_rcan_syn_cr.png}&
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Canon_020_LR3_dsgan_vdsr_syn_real_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Canon_020_LR3_dml_rcan_syn_real_cr.png}
& \rotatebox[origin=rb]{-90}{RCAN \quad}
\\
\multirow{2}{*}{\shortstack{Reference \\GT patch}} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\end{tabular}
%----------------------------------------------------------------------------------------
\\
\\
\begin{tabular}{c}
\includegraphics[width=0.132\linewidth,height=0.120\linewidth]{images//supp//realsrx3//im3.JPG}\\
\end{tabular}
\begin{tabular}{ccccccc}
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Canon_005_LR3_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Canon_005_LR3_vdsr_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Canon_005_LR3_dsgan_vdsr_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Canon_005_LR3_dml_vdsr_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Canon_005_LR3_dsgan_rcan_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Canon_005_LR3_dml_vdsr_syn_real_cr.png}
& \rotatebox[origin=rb]{-90}{VDSR \quad}
\\
\multirow{2}{*}{LR patch} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\\
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Canon_005_HR_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Canon_005_LR3_rcan_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Canon_005_LR3_dsgan_rcan_syn_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Canon_005_LR3_dml_rcan_syn_cr.png}&
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Canon_005_LR3_dsgan_rcan_syn_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx3//Canon_005_LR3_dml_rcan_syn_cr.png}
& \rotatebox[origin=rb]{-90}{RCAN \quad}
\\
\multirow{2}{*}{\shortstack{Reference \\GT patch}} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\end{tabular}
%----------------------------------------------------------------------------------------
\end{tabular}}
\caption{Visual comparison of the competing SISR models on RealSR \cite{realsr} dataset with zooming factor $\times$3. The first and second rows of each example are super-resolved patches by VDSR and RCAN networks, respectively, which are trained using different training data.}
\label{fig:supp_realsr_3}
\end{figure*}
%----------------------------------------------------------------------------------------







%------------------------------------------------------------------------------
\begin{figure*}[!tp]
%\vspace{-5mm}
\scriptsize
\centering
\setlength{\tabcolsep}{0.3mm}{
\begin{tabular}{cc}
%------------------------------------------------------
\begin{tabular}{c}
\includegraphics[width=0.132\linewidth,height=0.120\linewidth]{images//supp//realsrx4//im1.JPG}\\
\end{tabular}
\begin{tabular}{ccccccc}
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Nikon_041_LR4_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Nikon_041_LR4_vdsr_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Nikon_041_LR4_dsgan_vdsr_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Nikon_041_LR4_r_k15n8_vdsr_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Nikon_041_LR4_dsgan_vdsr_syn_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Nikon_041_LR4_r_k15n8_vdsr_syn_cr.png}
& \rotatebox[origin=rb]{-90}{VDSR \quad}
\\
\multirow{2}{*}{LR patch} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\\
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Nikon_041_HR_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Nikon_041_LR4_rcan_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Nikon_041_LR4_dsgan_rcan_syn_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Nikon_041_LR4_r_k15n8_rcan_syn_cr.png}&
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Nikon_041_LR4_dsgan_rcan_syn_real_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Nikon_041_LR4_r_k15n8_rcan_syn_cr.png}
& \rotatebox[origin=rb]{-90}{RCAN \quad}
\\
\multirow{2}{*}{\shortstack{Reference \\GT patch}} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\end{tabular}
%----------------------------------------------------------------------------------------
\\
\\
\begin{tabular}{c}
\includegraphics[width=0.132\linewidth,height=0.120\linewidth]{images//supp//realsrx4//im3.JPG}\\
\end{tabular}
\begin{tabular}{ccccccc}
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Nikon_006_LR4_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Nikon_006_LR4_vdsr_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Nikon_006_LR4_dsgan_vdsr_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Nikon_006_LR4_r_k15n8_vdsr_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Nikon_006_LR4_dsgan_vdsr_syn_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Nikon_006_LR4_r_k15n8_vdsr_syn_cr.png}
& \rotatebox[origin=rb]{-90}{VDSR \quad}
\\
\multirow{2}{*}{LR patch} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\\
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Nikon_006_HR_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Nikon_006_LR4_rcan_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Nikon_006_LR4_dsgan_rcan_syn_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Nikon_006_LR4_r_k15n8_rcan_syn_cr.png}&
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Nikon_006_LR4_dsgan_rcan_syn_real_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Nikon_006_LR4_r_k15n8_rcan_syn_cr.png}
& \rotatebox[origin=rb]{-90}{RCAN \quad}
\\
\multirow{2}{*}{\shortstack{Reference \\GT patch}} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\end{tabular}
%----------------------------------------------------------------------------------------
\\
\\
\begin{tabular}{c}
\includegraphics[width=0.132\linewidth,height=0.120\linewidth]{images//supp//realsrx4//im2.JPG}\\
\end{tabular}
\begin{tabular}{ccccccc}
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Canon_050_LR4_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Canon_050_LR4_vdsr_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Canon_050_LR4_dsgan_vdsr_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Canon_050_LR4_r_k15n8_vdsr_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Canon_050_LR4_dsgan_vdsr_syn_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Canon_050_LR4_r_k15n8_vdsr_syn_real_cr.png}
& \rotatebox[origin=rb]{-90}{VDSR \quad}
\\
\multirow{2}{*}{LR patch} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\\
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Canon_050_HR_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Canon_050_LR4_rcan_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Canon_050_LR4_dsgan_rcan_syn_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Canon_050_LR4_r_k15n8_rcan_syn_cr.png}&
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Canon_050_LR4_dsgan_rcan_syn_real_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//realsrx4//Canon_050_LR4_r_k15n8_rcan_syn_cr.png}
& \rotatebox[origin=rb]{-90}{RCAN \quad}
\\
\multirow{2}{*}{\shortstack{Reference \\GT patch}} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\end{tabular}
%----------------------------------------------------------------------------------------
\end{tabular}}
\caption{Visual comparison of the competing SISR models on RealSR \cite{realsr} dataset with zooming factor $\times$4. The first and second rows of each example are super-resolved patches by VDSR and RCAN networks, respectively, which are trained using different training data.}
\label{fig:supp_realsr_4}
\end{figure*}
%----------------------------------------------------------------------------------------














%------------------------------------------------------------------------------
\begin{figure*}[!tp]
%\vspace{-5mm}
\scriptsize
\centering
\setlength{\tabcolsep}{0.3mm}{
\begin{tabular}{cc}
%------------------------------------------------------
\begin{tabular}{c}
\includegraphics[width=0.132\linewidth,height=0.120\linewidth]{images//supp//x2//im2.JPG}\\
%Image from\\ SR-RGB \cite{LearnToZoom}\\
\end{tabular}
\begin{tabular}{ccccccc}
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00366_LR2_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00366_rcan_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00366_dsgan_vdsr_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00366_dml_vdsr_syn_cr} &
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00366_dsgan_vdsr_syn_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00366_dml_vdsr_syn_real_cr.png}
& \rotatebox[origin=rb]{-90}{VDSR \quad\quad}
\\
\multirow{2}{*}{LR patch} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\\
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00366_HR_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00366_rcan_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00366_dsgan_rcan_syn_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00366_dml_rcan_syn_cr.png}&
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00366_dsgan_rcan_syn_real_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00366_dml_rcan_syn_real_cr.png}
& \rotatebox[origin=rb]{-90}{RCAN \quad\quad}
\\
\multirow{2}{*}{\shortstack{Reference \\GT patch}} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\end{tabular}
%----------------------------------------------------------------------------------------
\\
\\
\begin{tabular}{c}
\includegraphics[width=0.132\linewidth,height=0.120\linewidth]{images//supp//x2//im0.JPG}\\
% Image from\\ SR-RGB \cite{LearnToZoom}\\
\end{tabular}
\begin{tabular}{ccccccc}
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00349_LR2_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00349_vdsr_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00349_dsgan_vdsr_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00349_dml_vdsr_syn_cr} &
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00349_dsgan_vdsr_syn_real_cr.png} &
%{images//realsr_x4//realsr//Nikon_040_LR4_r_k15n8_vdsr_syn_real_cr.png}&
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00349_dml_vdsr_syn_real_cr.png}
& \rotatebox[origin=rb]{-90}{VDSR \quad}
\\
\multirow{2}{*}{LR patch} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\\
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00349_HR_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00349_rcan_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00349_dsgan_rcan_syn_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00349_dml_vdsr_syn_cr.png}&
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00349_dsgan_rcan_syn_real_cr.png}  &
%{images//realsr_x4//realsr//Nikon_040_LR4_r_k15n8_rcan_syn_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00349_dml_vdsr_syn_cr.png}
& \rotatebox[origin=rb]{-90}{RCAN \quad}
\\
\multirow{2}{*}{\shortstack{Reference \\GT patch}} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\end{tabular}
%----------------------------------------------------------------------------------------
\\
\\
\begin{tabular}{c}
\includegraphics[width=0.132\linewidth,height=0.120\linewidth]{images//supp//x2//im3.JPG}\\
%Image from\\ SR-RGB \cite{LearnToZoom}\\
\end{tabular}
\begin{tabular}{ccccccc}
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00169_LR2_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00169_vdsr_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00169_dsgan_vdsr_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00169_dml_vdsr_syn_cr} &
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00169_dsgan_rcan_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00169_dml_vdsr_syn_real_cr.png}
& \rotatebox[origin=rb]{-90}{VDSR \quad}
\\
\multirow{2}{*}{LR patch} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\\
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00169_HR_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00169_rcan_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00169_dsgan_rcan_syn_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00169_dml_vdsr_syn_real_cr.png}&
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00169_dsgan_rcan_syn_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//x2//00169_dml_vdsr_syn_real_cr.png}
& \rotatebox[origin=rb]{-90}{RCAN \quad}
\\
\multirow{2}{*}{\shortstack{Reference \\GT patch}} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\end{tabular}
%----------------------------------------------------------------------------------------
\end{tabular}}
\caption{Visual comparison of the competing SISR models on SR-RGB \cite{LearnToZoom} dataset with zooming factor $\times$2. The first and second rows of each example are super-resolved patches by VDSR and RCAN networks, respectively, which are trained using different training data.}
\label{fig:supp_2}
\end{figure*}
%----------------------------------------------------------------------------------------






%------------------------------------------------------------------------------
\begin{figure*}[!tp]
%\vspace{-5mm}
\scriptsize
\centering
\setlength{\tabcolsep}{0.3mm}{
\begin{tabular}{cc}
%------------------------------------------------------
\begin{tabular}{c}
\includegraphics[width=0.132\linewidth,height=0.120\linewidth]{images//supp//x3//im1.JPG}\\
%Image from\\ SR-RGB \cite{LearnToZoom}\\
\end{tabular}
\begin{tabular}{ccccccc}
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00434_LR3_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00434_vdsr_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00434_dsgan_vdsr_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00434_dml_vdsr_syn_cr} &
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00434_dsgan_vdsr_syn_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00434_dml_vdsr_syn_real_cr.png}
& \rotatebox[origin=rb]{-90}{VDSR \quad}
\\
\multirow{2}{*}{LR patch} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\\
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00434_HR_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00434_rcan_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00434_dsgan_rcan_syn_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00434_dml_rcan_syn_cr.png}&
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00434_dsgan_rcan_syn_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00434_dml_rcan_syn_real_cr.png}
& \rotatebox[origin=rb]{-90}{RCAN \quad}
\\
\multirow{2}{*}{\shortstack{Reference \\GT patch}} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\end{tabular}
%----------------------------------------------------------------------------------------
\\
\\
\begin{tabular}{c}
\includegraphics[width=0.132\linewidth,height=0.120\linewidth]{images//supp//x3//im2.JPG}\\
%Image from\\ SR-RGB \cite{LearnToZoom}\\
\end{tabular}
\begin{tabular}{ccccccc}
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00101_LR3_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00101_vdsr_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00101_dsgan_vdsr_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00101_dml_vdsr_syn_cr} &
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00101_dsgan_vdsr_syn_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00101_dml_vdsr_syn_real_cr.png}
& \rotatebox[origin=rb]{-90}{VDSR \quad}
\\
\multirow{2}{*}{LR patch} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\\
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00101_HR_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00101_rcan_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00101_dsgan_rcan_syn_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00101_dml_rcan_syn_cr.png}&
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00101_dsgan_rcan_syn_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00101_dml_rcan_syn_real_cr.png}
& \rotatebox[origin=rb]{-90}{RCAN \quad}
\\
\multirow{2}{*}{\shortstack{Reference \\GT patch}} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\end{tabular}
%----------------------------------------------------------------------------------------
\\
\\
\begin{tabular}{c}
\includegraphics[width=0.132\linewidth,height=0.120\linewidth]{images//supp//x3//im3.JPG}\\
%Image from\\ SR-RGB \cite{LearnToZoom}\\
\end{tabular}
\begin{tabular}{ccccccc}
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00169_LR3_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00169_vdsr_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00169_dsgan_vdsr_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00169_dml_vdsr_syn_real_cr} &
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00169_dsgan_vdsr_syn_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00169_dml_vdsr_syn_real_cr.png}
& \rotatebox[origin=rb]{-90}{VDSR \quad}
\\
\multirow{2}{*}{LR patch} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\\
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00169_HR_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00169_rcan_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00169_dsgan_rcan_syn_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00169_dml_rcan_syn_real_cr.png}&
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00169_dsgan_rcan_syn_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//x3//00169_dml_rcan_syn_real_cr.png}
& \rotatebox[origin=rb]{-90}{RCAN \quad}
\\
\multirow{2}{*}{\shortstack{Reference \\GT patch}} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\end{tabular}
\end{tabular}}
\caption{Visual comparison of the competing SISR models on SR-RGB \cite{LearnToZoom} dataset with zooming factor $\times$3. The first and second rows of each example are super-resolved patches by VDSR and RCAN networks, respectively, which are trained using different training data.}
\label{fig:supp_3}
\end{figure*}
%----------------------------------------------------------------------------------------

















%------------------------------------------------------------------------------
\begin{figure*}[!tp]
%\vspace{-5mm}
\scriptsize
\centering
\setlength{\tabcolsep}{0.3mm}{
\begin{tabular}{cc}
%------------------------------------------------------
\begin{tabular}{c}
\includegraphics[width=0.132\linewidth,height=0.120\linewidth]{images//supp//x4//im2.JPG}\\
%Image from\\ SR-RGB \cite{LearnToZoom}\\
\end{tabular}
\begin{tabular}{ccccccc}
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00062_LR4_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00062_00004_vdsr_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00062_00004_dsgan_vdsr_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00062_00004_r_k15n8_vdsr_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00062_00004_dsgan_vdsr_syn_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00062_00004_r_k15n8_vdsr_syn_real_cr.png}
& \rotatebox[origin=rb]{-90}{VDSR \quad}
\\
\multirow{2}{*}{LR patch} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\\
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00062_HR_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00062_00004_rcan_real_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00062_00004_dsgan_rcan_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00062_00004_r_k15n8_rcan_syn_cr.png}&
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00062_00004_dsgan_rcan_syn_real_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00062_00004_r_k15n8_rcan_syn_real_cr.png}
& \rotatebox[origin=rb]{-90}{RCAN \quad}
\\
\multirow{2}{*}{\shortstack{Reference \\GT patch}} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\end{tabular}
%----------------------------------------------------------------------------------------
\\
\\
\begin{tabular}{c}
\includegraphics[width=0.132\linewidth,height=0.120\linewidth]{images//supp//x4//im3.JPG}\\
%Image from\\ SR-RGB \cite{LearnToZoom}\\
\end{tabular}
\begin{tabular}{ccccccc}
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00341_LR4_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00341_00004_vdsr_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00341_00004_dsgan_vdsr_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00341_00004_r_k15n8_vdsr_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00341_00004_dsgan_vdsr_syn_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00341_00004_r_k15n8_vdsr_syn_real_cr.png}
& \rotatebox[origin=rb]{-90}{VDSR \quad}
\\
\multirow{2}{*}{LR patch} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\\
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00341_HR_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00341_00004_rcan_real_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00341_00004_dsgan_rcan_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00341_00004_r_k15n8_rcan_syn_cr.png}&
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00341_00004_dsgan_rcan_syn_real_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00341_00004_r_k15n8_rcan_syn_real_cr.png}
& \rotatebox[origin=rb]{-90}{RCAN \quad}
\\
\multirow{2}{*}{\shortstack{Reference \\GT patch}} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\end{tabular}
%----------------------------------------------------------------------------------------
\\
\\
\begin{tabular}{c}
\includegraphics[width=0.132\linewidth,height=0.120\linewidth]{images//supp//x4//im1.JPG}\\
%Image from\\ SR-RGB \cite{LearnToZoom}\\
\end{tabular}
\begin{tabular}{ccccccc}
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00101_LR4_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00101_00004_vdsr_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00101_00004_dsgan_vdsr_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00101_00004_r_k15n8_vdsr_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00101_00004_dsgan_vdsr_syn_real_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00101_00004_r_k15n8_vdsr_syn_real_cr.png}
& \rotatebox[origin=rb]{-90}{VDSR \quad}
\\
\multirow{2}{*}{LR patch} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\\
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00101_HR_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00101_00004_rcan_real_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00101_00004_dsgan_rcan_syn_cr.png} &
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00101_00004_r_k15n8_rcan_syn_cr.png}&
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00101_00004_dsgan_rcan_syn_real_cr.png}  &
\includegraphics[width=0.132\linewidth]
{images//supp//x4//00101_00004_r_k15n8_rcan_syn_real_cr.png}
& \rotatebox[origin=rb]{-90}{RCAN \quad}
\\
\multirow{2}{*}{\shortstack{Reference \\GT patch}} &
\multirow{2}{*}{RealSR} &
\multirow{2}{*}{Syn-DSGAN} &
\multirow{2}{*}{Syn-DML} &
\multirow{2}{*}{\shortstack{Syn-DSGAN\\ +RealSR}} &
\multirow{2}{*}{\shortstack{Syn-DML\\ +RealSR}}
\\
\end{tabular}
%----------------------------------------------------------------------------------------
\end{tabular}}
\caption{Visual comparison of the competing SISR models on SR-RGB \cite{LearnToZoom} dataset with zooming factor $\times$4. The first and second rows of each example are super-resolved patches by VDSR and RCAN networks, respectively, which are trained using different training data.}
\label{fig:supp_4}
\end{figure*}
%----------------------------------------------------------------------------------------












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