Chroma Key is a technique of layering two images or video streams together based on their colour hues or chroma range – hence the name Chroma Key. This technique is mainly used to remove the background from a person doing a live stream or recording, and is being used in newscasting, live streams and even movies. By using a Chroma Key, a certain colour in the footage is made transparent, which allows it to be replaced by a static image or separate background video.
All in all, this technique is very useful due to a multitude of reasons, but in this article we will focus on the most popular RTMP software encoders that offer chroma key functions, namely:
- OBS Studio
OBS Studio is a streaming app which offers chroma key functionality and the best part about it is that it’s really easy to use.
To enable chroma key, simply right click on your video source and select “Filters” from the menu. Now you will have the option of adding Audio/Video Filters or Effect Filters. Click on the + symbol under the Effect Filters section and select Chroma Key form the list. You will also have to add a name for your Chroma Key
Now you will be able to select the colour which you want to make transparent by double clicking the color box which will open the colour palette.
You will also have to set the “similarity”, “blend” and “spill reductions”. Tweak and test these settings until you get a satisfactory result and after that you can add your second source to preview how it will look.
If you want to see how OBS Studio works with WpStream, just check out our guide available HERE.
You can add a chroma key to your vMix stream by clicking on the “Add Input” button in left-hand window and add your video or camera input.
Now, double click on the image and click on “Colour Key” – you can now use the eye dropper tool to select the colour which you want to become transparent. Clicking on the “Auto Chroma Key” button will remove the green screen background and turn it into black by default.
Now click the “Add Input” button and select the media you want to use as a background. You can also opt for a few templates offered by vMix if you don’t have other available images or videos. Once that’s done, click on the “Set Up” button and start layering your input media with the foreground video in the “Talent” layer.
You can also check our article on live streaming to WpStream with vMix.
Xsplit has been designed to broadcast live gameplay streams, so it offers chroma key functions and tweaks which allow streamers to place images or videos over their gameplay footage. Even if it was developed with gameplay live streams in mind, Xsplit can be used for different types of streams which require the chroma key functionality.
To use the chroma key, you will have to set up your input layers in a way so that the foreground stream is higher than the image or video you are using for a background.
After positioning your two image or video sources and assigning their layer priority, simply right click on the foreground stream to open a new options menu. Now click on the “Colour” tab and hit the radio button to activate your chroma key. A new submenu will appear which will allow you to select the colour which will be made transparent. You can further test and tweak for optimal results.
VidBlaster offers chroma key in the form of an effect module. You can add a chroma key to your stream by clicking on the “Module” menu and then clicking “Add” and “Effect” from the pop-up which appears. Select “Chroma Key” from the pop-up and you will be able to select a foreground source and a background source. The background source can be a white screen, a program, an image or a camera.
Wirecast offers chroma key options in the shot editor and the settings can be changed even during a live broadcast. Accessing the editor can be done by right clicking on the camera source and then clicking on “Edit Shot”. From the new menu, click on the chroma key attributes button which opens a sub-menu with more options such as adding a video or image replacement for the chroma key. Wirecast also offers some interesting virtual templates which you can use, most of which are formed from several layers of media. After adding your chroma key, simply click “Go” and you will start streaming.
Regardless of the streaming app you are using, setting up a chroma key for your stream is fairly easy to do. It only takes a few minutes and your stream will look better than ever – more professional and more engaging.
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