Visible-invisible background prompter
AssigneeiMatte, Inc.
InventorsPaul Vlahos, Petro Vlahos
Life of this patent
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Abstract
A video signal is generated representative of a background scene, such as a weather map, which provides an outline of all the detail in the map. This outline detail is made visible to a foreground subject by projecting it onto a white screen behind the subject in a selected color such as green. The projector is selectively inhibited so as to prevent the background detail from projecting onto the foreground subject. The white screen and the green detail lines are removed and replaced by the background scene by an image compositing process. Prompts are visible to the foreground subject, but not visible to a home viewing audience.
Claims10
A method for projecting and then removing visible prompts comprising the steps of:
- a) computing reference RGB color ratios of a white screen,
- b) generating a binary matte signal from said color ratios that identifies areas of said white screen unobstructed by a subject as those pixels in a current image whose color ratios match reference color ratios, and all remaining pixels identify a subject area,
- c) generating a detail signal of a background scene by differentiating its red, green and blue components,
- d) inhibiting said detail signal in said subject area,
- e) projecting said inhibited detail signal onto said white screen,
- f) removing from a camera signal said projected inhibited detail signal by reducing the level of the color of each pixel of said detail signal to a level that results in the pixel's color ratios equaling those of the white screen,
- g) generating a linear matte signal by calculating the percent contribution of the background to the image in a current frame,
- h) removing the contribution of the background scene from a current image frame, by subtracting the product of the linear matte signal and a selected clear frame signal, to create a processed foreground image for use as input to a compositing system.
Dependencies are inferred from the claim text.