视频演示：
资源介绍：
UnMult是一款免费插件，兼容After Effects、Premiere Pro和Media Encoder，用于将黑色背景去除并生成透明通道。它可以为光效素材（如镜头光晕、炫光等）创建Alpha通道，让这些效果直接在Normal正常混合模式下叠加到画面中，而无需使用叠加或屏幕模式。插件的工作原理是对RGB通道进行“反预乘”处理，使颜色达到完整饱和度，并同步调整Alpha值，从而得到半透明的真实效果。非常适合处理基于黑底的光效素材，简洁高效，且完全免费。
The UnMult plug-in generates an alpha channel for a lighting effect, allowing it to be applied to your footage using the Normal transfer mode in After Effects or another program. It does this by un-premultiplying the RGB to reach full saturation and then attenuating the alpha by the same amount.
UnMult assumes your lighting effect (a lens flare, for example) is applied to a black solid with a fully opaque alpha channel. After applying UnMult, the lighting effect may appear unchanged, but the pixel values will have been modified to use a semi-transparent alpha.
