# how to label and refer subfigures under tabular environment?

I have two subfigures and I need to refer them in text such as Fig. 1.1(a) and Fig. 1.1(a) using Fig. \ref{fig1.1a:chap1} and Fig. \ref{fig1.1b:chap1}. The output is not coming. Instead, a double question mark (Fig. ??) appears. How to resolve this?

\documentclass[12pt, a4paper, oneside]{Thesis}
\usepackage{amsmath}
\usepackage{graphicx}
\usepackage{caption}
\usepackage{subfigure}

\begin{document}
\begin{figure}
\centering
\begin{tabular}{@{}c@{}}
\includegraphics[width=\linewidth,height=125pt]{enrollment} \label{fig1.1a:chap1} \\[\abovecaptionskip]
\small (a) Enrollment phase
\end{tabular}
\vspace{\floatsep}
\begin{tabular}{@{}c@{}}
\includegraphics[width=\linewidth,height=125pt]{verification} \label{fig1.1b:chap1} \\[\abovecaptionskip]
\small (b) Verification phase
\end{tabular}
\caption{Mode of operations in a biometric authentication system}\label{fig1.1:chap1}%
\end{figure}
\end{document}

• Please add a full MWE, starting with \documentclass and ending with \end{document}, with the needed packages. – NBur Oct 12 at 6:34
• @NBur Suggestions done. – rudresh dwivedi Oct 12 at 6:37
• package subfigure is obsolete. use subfig insteadit or subcaption (which is more powerful). it load is not suficient, you should use its macro in table composition and than compile document at least twice. – Zarko Oct 12 at 6:40
• @Zarko I am getting everything from it except the correct reference. ?? appears when I use \label and \ref. – rudresh dwivedi Oct 12 at 6:42
• @rudreshdwivedi, see my answer below. with your code you can't obtain what you expect. – Zarko Oct 12 at 6:59

your approach to show two sub figures is at least unusual, frankly said wrong:

• you load obsolete package subfigure but than not use it. loading it is not sufficient, you should use its environment in figure composition and than compile document at least twice
• package subfigure is deprecated. use subfig instead it or subcaption (which is more powerful).
• references work on labels, which follows captions. that is not a case in your code example
• it is not clear, what is purpose of tables used in your images
• see if the following example works for you (i didn't use thesis document class, since i don't know which one you use. but this not influence on obtained result). after two compilation you will obtain working references

\documentclass{report} % <--- instead of "thesis" which i haven't
\usepackage{amsmath}
\usepackage{graphicx}
\usepackage{caption}
\usepackage{subcaption} % <--- it is not compatible with "subfigure"
% with it you had to replace "subfigure"

\usepackage{lipsum}     % <--- for dummy text

\begin{document}
\lipsum[1]
\begin{figure}[htb]     % <---
\centering
\begin{subfigure}[b]{0.6\linewidth}     % <---
\includegraphics[width=\linewidth]{example-image-duck}
\caption{Enrollment phase}          % <---
\label{fig1.1a:chap1}
\end{subfigure}                         % <---

\begin{subfigure}[b]{0.6\linewidth}     % <---
\includegraphics[width=\linewidth]{example-image-duck}
\caption{Verification phase}        % <---
\label{fig1.1b:chap1}
\end{subfigure}                         % <---
\caption{Mode of operations in a biometric authentication system}
\label{fig1.1:chap1}%
\end{figure}
Test of references: see subfigures \ref{fig1.1a:chap1}  and \ref{fig1.1b:chap1} in figure \ref{fig1.1:chap1}.
\end{document}


with % <--- are indicated changes in comparison to your document example. if you like to have wide images, than change width of subfigure to desired width.

you may be lucky and will can use subfigure package ... :-) :

    \documentclass{report}
\usepackage{amsmath}
\usepackage{graphicx}
\usepackage{caption}
\usepackage{subfigure} % <---

\usepackage{lipsum}

\begin{document}
\lipsum[1]
\begin{figure}[htb]     % <---
\centering
\subfigure[Enrollment phase \label{fig1.1a:chap1}]%
{
\includegraphics[width=0.6\linewidth]{example-image-duck}
}

\subfigure[Verification phase \label{fig1.1b:chap1}]%
{
\includegraphics[width=0.6\linewidth]{example-image-duck}
}
\caption{Mode of operations in a biometric authentication system}
\label{fig1.1:chap1}%
\end{figure}
Test of references: see subfigures \ref{fig1.1a:chap1}  and \ref{fig1.1b:chap1} in figure \ref{fig1.1:chap1}.
\end{document}


result is similar as before, however you may experienced new problems with it.

• Error: Package subcaption Error: This package can't be used in cooperation(subcaption) with the subfigure package. \subcaption@CheckCompatibility – rudresh dwivedi Oct 12 at 7:02
• when you use subcaption in document, you need to delete subfigure from preamble! – Zarko Oct 12 at 7:04
• how to delete that from preamble?? – rudresh dwivedi Oct 12 at 7:05
• you could help from this \documentclass which I am using: sharelatex.com/templates/thesis/… – rudresh dwivedi Oct 12 at 7:24
• @rudreshdwivedi, do you test my mwe as it is? if it work, please than try again with thesis instead report. if with thesis will not work, than you can consider ˙thesis as obsolete and you need to find more up-to-date document class or you try a luck and use subfigure environments from subfigure package. see addendum to my answer will appear asap) – Zarko Oct 12 at 10:21