Green screen is often used when shooting videos or photos in order to later combine two images/videos replacing the green background with another one. The Chroma Key effect available in green screen video editing software allows to make the overlaid image backdrop transparent so that a layer underneath becomes visible.
Using such software you can easily create a slideshow out of your photos with unusual landscape scenes in the background or insert an animated character into you video that will move over the video image during the file playback.
You will need the following:
Now you can follow the steps below to overlay your photo or video over any background footage.
Step 1: Add your background and foreground footage to the timeline
First add the video/image you want to use as a background. Drag and drop it to the Main Video line of the Timeline.
Then add the video/image you want to superpose over the main video. Drag and drop it to the Video Overlay line of the Timeline.
If necessary, you can change the upper-layer video position and duration.
To change the position of the foreground video in the movie, left-click it and drag left or right to a new position.
To change the duration of the foreground video, you can cut out unnecessary parts at the beginning and the end of the video by dragging its left boundary to the right or right boundary to the left at the Timeline.
Step 2: Apply the Chromakey effect
Select the video/image at the Video Overlay line of the Timeline and click the Edit Overlay button on the Timeline Toolbar.
A new window will open. By default, the foreground video/image is centered on the screen. You can make the following adjustments:
Activate the Chromakey effect checking the corresponding box in the right part of the window. So that the effect can be clearly distinguished, set a greater value dragging the Chromakey slider below.
You can select colors to be transparent using the Append Color option. Click the black arrow to open the color palette and select the color that forms the area you would like to be transparent. If you want to choose several colors, just repeat this operation. If you don't like the result use the Reset all colors button to discard the changes.
You can also pick a color from the image. To do that click the color field and move the color picker to find the appropriate color. To select colors with more precision, zoom in the image choosing the necessary zoom value from the Zoom drop-down list.
That's all, now your foreground picture has the transparent background.
Step 3: Playback the file to make sure the desired result is achieved
Preview your video with the applied Chroma Key effect to make sure you got the necessary result. Please, press the button within the Preview Area of the same window to start playback.
If you are completely satisfied with your video, click the OK button to accept all the changes and close the Video Overlay properties window. Then you can save the current project, as well as the edited video file into one of the supported formats. To learn more about it, read the How to save the project and the video in AVS Video Editor? guide.