Overview and Strategy
At some point, you may want to port an animation from
one format to another or from one program to another.
There are a lot of animation programs and a few formats
in wide use. This series of tutorials will take up the
following formats and programs:
|Audio Video Interleave
|Graphics Interchange Format (GIF89a)
Apple QuickTime Pro
Jasc® Animation Shop
Although there are many more programs to consider,
I chose these because of their popularity. These programs
have a lot of flexibility, and this reason alone can
explain their popularity.
When porting any image the goal is to obtain the format
of choice with no loss in quality. When porting animations
there is an additional goal to do it in the least amount
of time. This is because an animation (or movie) is
made up of a number of individual frame images. The
trick is to port the entire image sequence in one step
and avoid having to extract or import them one at a
The color depth and compression of the frame images
are paramount in order to attain the best quality when
moving them from one format or program to another. Images
stored in AVI or MOV formats can be true color (more
here on color depth). Bear in mind that any GIF
file has a limited color palette by definition. GIF
files only support a maximum of 256 colors, so when
porting frame images from one program or format to another,
keep this in mind. If you start out with a true color
image, you can always generate a GIF file from it. This
will ensure that all the colors will be available to
create the palette. However, if the frames are GIF files
to begin with, the resulting animation will not have
any more colors than the ones it started with.
Image compression is another factor affecting quality.
When you generate an Apple QuickTime movie or Windows®
AVI file, you can elect to use image compression. If
you use a lossy compression scheme such as JPEG, this
will lower the image quality of the frames (more
here on the JPEG format). GIF uses a lossless compression
scheme, so if you're not concerned about a limit of
256 colors then at least image quality can be maintained
when using the GIF format to port animations. I emphasize
that quality "can" be maintained, because
you still have to make sure there is no reduction in
Porting an Image Sequence in One Step
Not all programs support the import or export of an
entire image sequence. This can be a huge time saver
and should always be taken into consideration. If faced
with a choice whether to save or import images one at
a time or all at once, the choice should be obvious.
The next tutorial will detail which programs do and
which ones don't.
So the porting strategy you should use is twofold:
1. Port the images with no loss in quality
2. Try to port the image sequence in a single step.
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