image (not thumbnails funcs) (tag)
file_is_displayable_image() | Validate that file is suitable for displaying within a web page. |
next_image_link() | Displays next image link that has the same post parent. |
previous_image_link() | Displays previous image link that has the same post parent. |
wp_get_additional_image_sizes() | Gets data of all additionally registered image sizes (thumbnails). |
wp_get_attachment_url() | Retrieve the URL for an attachment. |
wp_read_image_metadata() | Get extended image metadata, exif or iptc as available. |