How to show figures in two columns in latex

I'm trying to show 7 figures in two columns in IEEE conference format latex. I need each column's width to be equal to the half width of the page. so the two columns should takes the entire width of the page. Here is what I have tried to show 4 out of those 7 figures in latex according to the following link 'https://tex.stackexchange.com/questions/501488/place-4-figures-side-by-side-in-2-column-latex-document':

\begin{figure*}
    %\centering % Not needed
    \begin{subfigure}[b]{1\columnwidth}
        \includegraphics[width=\textwidth]{out_1.png}
    \end{subfigure}
    \hfill
    \begin{subfigure}[b]{1\columnwidth}
        \includegraphics[width=\textwidth]{out_2.png}
    \end{subfigure}
    %% leave a blank line to create a line break
    \begin{subfigure}[b]{1\columnwidth}
        \includegraphics[width=\textwidth]{out_3.png}
    \end{subfigure}
    \hfill
    \begin{subfigure}[b]{1\columnwidth}
        \includegraphics[width=\textwidth]{out_4.png}
    \end{subfigure}
    \caption{Four Figures}
    \label{fig:four figures}
\end{figure*}

But, My problem is the figures appear small and blur and the width of each figure is not equal to the width of half of the page. H appreciate if any one can help me with this problem. Even when I use the following code to show 1 figure with the width of almost the whole page, it shows the figure small and in the left column of my document.

\begin{figure*}
    \centering
    \includegraphics[width=0.8\textwidth]{out.jpg}
    \caption{This is a wide figure that spans both columns.}
    \label{fig:img1}
\end{figure*}