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.