Which term describes the method to isolate a subject against a background using color?

The method that describes isolating a subject against a background using color is known as chroma key. This technique involves removing a specific color range from the footage, typically a bright green or blue background, to allow another image or video to be displayed in that area. This process is commonly used in film production and video editing to create a composite image where the subject appears to be in a different environment.

Chroma key works by detecting and eliminating the chosen color, making it transparent, and thus enabling the background to be changed easily. The effectiveness of chroma key relies heavily on even lighting and solid colors in the background to ensure that the subject is cleanly isolated without any remnants of the background color.

While color grading enhances the overall look and mood of the footage, and masking allows for selective editing within a frame, neither directly describes the specific action of removing a color from a background to isolate a subject. Digital keying refers to the broader process of keying out portions of footage, but chroma key specifically refers to the color-based technique, making it the most precise term for this method.