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<title>PNG Third Edition: animated PNG, dispose ops</title>
<link rel="author" title="Philip Taylor" href="mailto:excors@gmail.com">
<link rel="author" title="Chris Lilley" href="mailto:chris@w3.org">
<link rel="help" href="https://www.w3.org/TR/png-3/#apng-frame-based-animation">
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<meta name="assert" content="the frame's region of the output buffer is to be cleared to fully transparent bla