Add Image to title/sidebar

Hello,

My sidebar is using the site name as the “header.” The code is below:

<h1><a href="<?php echo site_url('') ?>" title="<?php echo __('Home page', 'free01') ?>"><?php echo bloginfo( 'name' ); ?> </a> </h1>

I’m okay with that. However, I want to add an image to the sidebar. The image is sitting in the theme folder under the name “iris.jpg.”

How would I change the code to include the image?