Specifications

Chapter 3 Media 35
Transparency Some image formats include transparency information in addition to the image
itself. This transparency information is sometimes referred to as an “alpha
channel”, although some image editing applications use this term for other
functions. Transparency can be used to create non-square images, holes inside
images or semi-transparent areas, such as drop shadows. Photoshop, PNG,
TIFF and Targa file are examples of file formats that support transparency.
▲ CAUTION: Even if an application supports writing to a particular file format,
it may not support transparency in that format. Perform tests with images to
determine the suitability of particular formats and applications.
WATCHOUT supports most methods used for encoding transparency into
images. Which method to use is usually determined automatically. If not, you
can specify this manually by opening the Specifications dialog box for the
image and choosing the desired encoding (see “Transparency” on page 142).
+=
Background image. Image with a transparent back-
ground and a semi-transparent
shadow.
Result when composited in
WATCHOUT.