[{"data":1,"prerenderedAt":240},["ShallowReactive",2],{"content:\u002Fposts\u002F77ba0f1":3,"surround:\u002Fposts\u002F77ba0f1":233},{"id":4,"title":5,"body":6,"categories":205,"date":207,"description":208,"donation":209,"draft":210,"extension":211,"image":212,"meta":213,"navigation":209,"path":215,"permalink":215,"published":212,"readingTime":216,"recommend":212,"references":221,"seo":225,"sitemap":226,"stem":227,"tags":228,"type":230,"updated":231,"__hash__":232},"content\u002Fposts\u002F2026\u002Fmotion-extraction.md","使用 Pr 实现运动提取（Motion Extraction）",{"type":7,"value":8,"toc":196},"minimark",[9,18,23,26,29,34,40,126,131,134,137,140,143,146,149,152,158,162,165,170,173,176,184,187,190,193],[10,11,12,13,17],"p",{},"最近在网上冲浪时，刷到了 Posy 的 ",[14,15,16],"strong",{},"运动提取","：",[19,20],"video-embed",{"id":21,"type":22},"BV1Uc411i7dq","bilibili",[10,24,25],{},"视频里，静止的部分被压了下去，而原本很难注意到的小幅运动被凸显了出来。",[10,27,28],{},"大概明白原理后，我用 Pr 复现了一遍。",[30,31,33],"h2",{"id":32},"在-pr-里复现","在 Pr 里复现",[35,36],"pic",{":height":37,"caption":38,"src":39},"320","原画、灰底运动、黑底运动与 RGB 时间错位","https:\u002F\u002Fassets.kayro.cn\u002Fblog\u002Fmotion_extraction_1786798898.webp",[41,42,44,75,89],"tab",{":tabs":43},"[\"灰底运动\",\"黑底运动\",\"RGB 时间错位\"]",[45,46,48],"template",{"v-slot:tab1":47},"",[49,50,51,55,66,72],"ol",{},[52,53,54],"li",{},"在 V1 放入原视频，再复制一层到 V2",[52,56,57,58,62,63],{},"给 V2 添加 ",[59,60,61],"code",{"code":61},"反转（视频）","，通道保持 ",[59,64,65],{"code":65},"RGB",[52,67,68,69],{},"把 V2 的不透明度设置为 ",[59,70,71],{"code":71},"50%",[52,73,74],{},"将 V2 和 V1 错开一段时间",[45,76,77],{"v-slot:tab2":47},[49,78,79,81,83],{},[52,80,54],{},[52,82,74],{},[52,84,85,86],{},"把 V2 的混合模式设置为 ",[59,87,88],{"code":88},"差值",[45,90,91],{"v-slot:tab3":47},[49,92,93,104,107,113,116],{},[52,94,95,96,99,100,103],{},"在 ",[59,97,98],{"code":98},"Lumetri 颜色"," 里将原视频的饱和度设置为 ",[59,101,102],{"code":102},"0","，此时视频呈现灰色",[52,105,106],{},"将视频复制三层，分别作为 R、G、B 通道",[52,108,95,109,112],{},[59,110,111],{"code":111},"Lumetri 颜色 → RGB 曲线"," 中，每层只保留一个通道：R 层压掉 G、B，G 层压掉 R、B，B 层压掉 R、G",[52,114,115],{},"R 层保持不动，G 层向后错开一段时间，B 层在 G 层基础上再向后错开相同的时间",[52,117,118,119,122,123],{},"底层混合模式保持 ",[59,120,121],{"code":121},"正常","，其余两层使用 ",[59,124,125],{"code":125},"线性减淡（添加）",[10,127,128,17],{},[14,129,130],{},"完整成品视频",[19,132],{"id":133,"type":22},"BV1JLuU6fEhp",[10,135,136],{},"三种做法都会用到不同时刻的画面。间隔越短，看到的越接近瞬时变化；间隔拉大后，不明显的变化会更容易看出来。",[10,138,139],{},"具体错开多少没有固定值，可以先从几帧开始，再根据效果调整。",[30,141,142],{"id":142},"灰底运动",[10,144,145],{},"V2 反相后，画面的 RGB 三通道会翻转。把它以 50% 的不透明度叠在原画上，两层对齐时，原画和反相画面相互抵消，画面变成中灰色。",[10,147,148],{},"错开时间后，发生变化的地方无法继续保持中灰，运动就会从灰色中凸显出来。",[30,150,151],{"id":151},"黑底运动",[10,153,154,155,157],{},"Pr 的 ",[59,156,88],{"code":88}," 会比较上下两层对应像素的差异。两层相同的地方差值为 0，呈现黑色，前后发生变化的区域则会凸显出来。",[30,159,161],{"id":160},"rgb-时间错位","RGB 时间错位",[10,163,164],{},"把饱和度设置成 0，视频变成灰色，复制三层，分别只保留 R、G、B 中的一个通道。",[10,166,167,169],{},[59,168,125],{"code":125}," 的作用就是把上下图层对应像素的颜色值相加。用于合并 R、G、B 三通道，重新组成 RGB 画面。",[10,171,172],{},"三层完全同步时，R、G、B 三个通道的亮度相同，合成结果还是灰色。",[10,174,175],{},"错开时间后，同一个位置在三个时刻的亮度不同，于是运动边缘有了颜色。",[177,178,181],"alert",{"title":179,"type":180},"运动提取不等于运动识别","warning",[10,182,183],{},"这些做法只是在比较同一个位置的像素前后有没有变化。任何变化都会被算进去，所以固定机位、曝光稳定的素材更适合这种效果。",[30,185,186],{"id":186},"模糊和辉光",[10,188,189],{},"模糊可以压掉细碎纹理和压缩噪声，让结果更干净，但开得太大会把细小运动一起抹掉。",[10,191,192],{},"参与比较的图层要使用相同的模糊参数，不然模糊本身也会产生差值。",[10,194,195],{},"运动提取完成后，可以给结果加上辉光，再叠回原画，让运动区域更明显。",{"title":47,"searchDepth":197,"depth":197,"links":198},4,[199,201,202,203,204],{"id":32,"depth":200,"text":33},2,{"id":142,"depth":200,"text":142},{"id":151,"depth":200,"text":151},{"id":160,"depth":200,"text":161},{"id":186,"depth":200,"text":186},[206],"技术","2026-08-12 02:21:27","使用 Pr 复现 Posy 的运动提取，并简要讲解灰底、黑底与 RGB 时间错位的原理。",true,false,"md",null,{"slots":214},{},"\u002Fposts\u002F77ba0f1",{"text":217,"minutes":218,"time":219,"words":220},"4 min read",3.725,223500,745,[222],{"title":223,"link":224},"【Posy双语】运动提取 Motion Extraction","https:\u002F\u002Fwww.bilibili.com\u002Fvideo\u002FBV1Uc411i7dq\u002F",{"title":5,"description":208},{"loc":215},"posts\u002F2026\u002Fmotion-extraction",[229],"图像处理","tech","2026-08-15 23:57:03","LUNOTArp56QpC8Kq2qmXU_cPvwxRi1W4hqbZ4pSTLms",[234,212],{"title":235,"path":236,"stem":237,"date":238,"type":239,"children":-1},"嗯","\u002Fposts\u002Ffb927f2","posts\u002F2026\u002Fen","2026-08-11 22:56:55","story",1786878865044]