This plugin parses anything that's between its opening and closing tags and returns URLs for images in <img> html tags that are found in the text.
You can use 'prepend' and 'append' parameters to add something at the beginning/end of each row.
Example:
{exp:channel:entries limit="1"}
Set OpenGraph tags using images in body
{exp:extract_image prepend='<meta property="og:image" content="' append='" />'}
{body}
{/exp:extract_image}
{/exp:channel:entries}