Cutting the backgrounds out of videos without using a green screen can be done through a process called rotoscoping. Rotoscoping is a technique used in animation and film production to trace over live-action footage frame by frame to create a matte, or a silhouette, of a subject. This matte can then be used to isolate the subject from the background.
To begin the process of rotoscoping, the video is imported into a software program, such as Adobe After Effects or Photoshop. The editor then selects the subject they wish to isolate and begins tracing around the edges of the subject with a pen tool. This process is repeated for every frame of the video.
Once the subject has been completely traced, the editor can then create a matte by filling in the traced lines with a solid color, such as white or black. The matte can then be applied to the video to isolate the subject from the background.
While rotoscoping can be an effective method for cutting backgrounds out of videos, it is a time-consuming process that requires a great deal of skill and patience. It can also be difficult to achieve a clean and accurate matte, particularly if the subject is moving quickly or has fine details such as hair or fur.
In addition to rotoscoping, there are other techniques that can be used to cut backgrounds out of videos without a green screen. One such technique is called luma keying, which involves isolating a subject based on its brightness values. This method works best when the subject is significantly brighter or darker than the background.
Another technique is called chroma keying, which is similar to green screen but uses a different color, such as blue. This method works best when the subject is not wearing green or blue clothing or has green or blue objects in the scene.
It should be noted that while these techniques can be effective, they are not always perfect and may require additional editing or touch-up work to achieve a seamless result.
- Adobe. (2021). Rotoscoping basics. Retrieved from https://helpx.adobe.com/after-effects/how-to/rotoscope-basics-aftereffects.html.