Graphics Programs Reference
In-Depth Information
transparency. Some of these pixels get colors from the background layers or
may not appear fully transparent. These pixels need to be ixed using the
matting technique.
The matting technique guides Photoshop to correct these edges or pixels
and let them match the background of the video or the image. For example,
if the image sequence or video ile will be displayed over a red background,
then it is a best practice to set the matting for the exported sequence of
images or the video ile to be red, which means that Photoshop can translate
the transparent edges better.
Note: When you export
the 3D animation to a
format that does not
support the alpha
channel, the Alpha
Channel option is
disabled.
Figure 13.10
Alpha Channel options.
The Alpha Channel settings include the following matting options, which will
help you understand how Photoshop reacts with the transparency of the
exported content:
• None: Avoids the alpha channel and the background of the exported
video, or images become as the same as the document background
color.
•
Straight-Unmatted: Exports the alpha channel with its default without
any matting color.
•
Premultiplied with Black: Mattes the alpha channel with black.
•
Premultiplied with White: Mattes the alpha channel with white.
•
Premultiplied with Color: Allows you to choose the matting color for the
alpha channel using the Color Picker.
As you can see in the following images, the matting afect appears with
antialiased pixels in the image edges. The following two igures show the
diference between an unmatted image's edges and an image matted with
red edges.
Frame Rate
Similar to the dimension presets, there are default video frame rates that are
associated with each standard. For example, the video output for the PAL
standard requires the video output frame rate to be 25 fps, and the NTSC
video standard requires the animation to be 29.97 fps.
In the Frame Rate section, you can choose the frame rate preset that suits
your output standard from the drop-down list, or you can add your custom
frame rate to the provided frame rate presets.
