This week our teacher showed us how to use the green screen for processing and how to use the Keyer and Colourspace nodes for color and saturation adjustment.
We can use the IBKGizmo and keylight nodes to deduct the green screen so that the object can be separated quickly
![](https://zhangyikun.myblog.arts.ac.uk/wp-content/plugins/lazy-load/images/1x1.trans.gif)
Then, we learned the node Keyer,
![](https://zhangyikun.myblog.arts.ac.uk/wp-content/plugins/lazy-load/images/1x1.trans.gif)
![](https://zhangyikun.myblog.arts.ac.uk/wp-content/plugins/lazy-load/images/1x1.trans.gif)
his node gives you access to several simple keyers. You can use it to pull keys based on the input image’s:
• red, green, or blue channel,
• red screen, greenscreen, or bluescreen,
• luminance (the default),
• saturation, or
• maximum and minimum values.
To use this node, view the alpha channel in the Viewer. Then, use the range graph to adjust the low and high pixel values of the matte. The A handle determines the low or transparent values of the key: any pixels that fall below this value are clipped to black. The B handle determines your high or opaque values: pixel values above this setting are clipped to white.
![](https://zhangyikun.myblog.arts.ac.uk/wp-content/plugins/lazy-load/images/1x1.trans.gif)
After that, I learned that I can get the part I want to highlight by using the phase subtraction of the color channel, but this paragraph is a little difficult to understand.
![](https://zhangyikun.myblog.arts.ac.uk/wp-content/plugins/lazy-load/images/1x1.trans.gif)
After that, a new node EdgeDetect, which is a node that detects edges, is also known. It can identify edges quickly.
![](https://zhangyikun.myblog.arts.ac.uk/wp-content/plugins/lazy-load/images/1x1.trans.gif)
After that, we learned a series of nodes such as colorlookup, which helps us to adjust colors faster.
For the final assignment, I used the channel color subtraction method to try to come up with the area I wanted, a knowledge I will have to continue to consolidate in the future.
![](https://zhangyikun.myblog.arts.ac.uk/wp-content/plugins/lazy-load/images/1x1.trans.gif)