An overlay ad is a promotional message that is inserted on top of another
media item. Overlay ad insertion can be the insertion of logos, images, or
scrolling text. Overlay ads may be solid or transparent.
For some media types, overlay ads must be merged with the underlying
media. For other media types (such as MPEG-4), overlay ads may be sent as
a separate file and merged by the viewing device. Overlay ads that can be
sent via a separate channel or stream may require less bandwidth and
appear cleaner (less fuzzy edges).
Overlay ads can be a low bandwidth solution that may be used on any type
of system and can be relatively simple and low cost addition. However, content licensing agreements may include restrictions on the modifying of programs prohibiting the use of digital overlay ads.
Logo insertion is placing of an image that identifies or is associated with a
company, product, or service. Advertisers may pay for the time logos appear
on programs or media.
Image placement is the process of inserting a graphic object into a display
area or within a media stream such as a television program. Images may be
static or they may be animated (change over time). For TV broadcasting systems, image inserts are typically inserted in programs based on their distribution networks.
A transparent overlay is a media object such as text or images that appear
on top of another media display (such as on top of a television program)
where the overlay image allows some of the underlying image to bleed
through.
Video text crawling is the displaying of text or image signals so they continuously move (crawl) across a video display.