Hi dmp007,
If you are developing custom component then you can make an ajax call with above given url which returns all the images matching search term.
Once you get the images paths, you can use below url to retrieve image meta data on clicking on the image
<host>:<port>/mnt/overlay/dam/gui/content/assets/metadataeditor.external.html?_charset_=utf-8&item=<image-path returned in first ajax call>
Ex: //<host>:<port>/mnt/overlay/dam/gui/content/assets/metadataeditor.external.html?_charset_=utf-8&item=/content/dam/we-retail/en/activities/hiking/hiking_5.jpg