Sony XVS-7000 Users Guide - Page 114

Key Adjustments (Menu) You can make the following adjustments using a menu operation. • Chroma key adjustments (see page 114) • Key edge modifications (see page 116) • Masks (see page 119) • DME effects for keys (see page 121) • Specifying the key output destination (see page 123) • Blink (see page 123) • Video process (see page 123) • Key modify clear (see page 123) This section describes adjustment of key 1 on the M/E-1 bank as an example. Chroma Key Adjustments Methods of adjusting the composite obtained from chroma keying include automatic adjustment with the auto chroma key function, and manual adjustment carrying out the necessary processing separately. The optimum results will be obtained by first carrying out adjustments with the auto chroma key function, then making any fine adjustments as required. The following manual adjustments are possible. Key active When disabled, only the foreground is output and you can make color cancel adjustments. Color cancel If the foreground image includes shades of the background color, this function removes the color from the foreground image. Window You can adjust the range over which the key signal is determined as matching the specified hue. When disabled, the default range is used for image adjustment. Chroma keying generates a key signal based on a particular color (reference color) in the foreground (typically a blue background), and the "window" refers to the range of colors which are regarded as matching this specified reference color to create the key signal. The region that makes up the key signal in the foreground (to be replaced by the background) appears as a fan shape with a cropped tip when viewed on a vectorscope. This region is specified by two parameters: an "Angle" parameter and a "Crop" parameter, which determines the degree of cropping. Crop a) Angle a) Hue value of reference color Region remaining as the foreground Region creating the key signal (replaced by the background) a) The Angle and Crop values do not change even if you use the auto chroma key function. Y balance In normal chroma keying, the key signal is based on the chrominance component only, and all elements of the foreground with the same hue are replaced by the background. Using the Y balance function, you can specify a luminance level range within which the key is active, and replace the specified part by the background. You can use the Y balance function independently on the key signal for the composition and the key signal for the color cancel function. When applied to the key signal for the composition, this produces the foreground with the color cancel effect applied. For example, this can therefore be used to provide an impression of smoke. When the Y balance function is applied to the color cancel key, the relevant part is output in its original color without canceling, and therefore it is possible to combine colors which are the same color as the background (i.e. typically blue) in the foreground. Chroma key shadow This function allows a shadow falling on the (typically blue) background color to be rendered more realistically. Since parts of the blue background darker than a specified intensity are treated as shadows, there is no effect on cutting out of the foreground. Video signal adjustment You can vary the foreground signal gain, or change the hue. There are separate adjustments for the gain of the overall video signal, and Y and C components. Adjusting auto chroma keys Auto chroma key is an automatic adjustment function which allows you to specify a part of the foreground video (for example, the blue background color) and use it as a reference for creating the chroma key image. 1 In the M/E-1 >Key1 >Type menu (1111), press [Chroma] in the group. 114