The Assemble HSY component assembles an image from the supplied H, S and Y channels according to the HSY color model. H, S and Y correspond to hue, saturation, and lightness respectively. The HSY color model is similar to the well-known HLS model, however, the HSY model has a notable advantage: its lightness (Y) channel takes human perception of color into account. For more information, see HSY Color Model. Assemble HSY is a map component, it can be located in the Channels category on the Components Bar. This component can output HDR colors.
Since all the channels are supplied by map inputs, their values can be controlled separately for different image areas by connecting a map component to the corresponding input. In this case the output brightness of the map component defines the channel value: black areas correspond to the value of 0, white areas to the maximum channel value (360 for the H channel and 100 for S and Y), and the values in-between are represented by intermediate brightness levels.
The alpha channel of the image produced by this component is always set to 100%; to set a different alpha channel, use the Set Alpha component.
H: Map Input
Defines the value of the Hue channel in the range between 0 and 360. Value of 0 yields red hue, 120 yields green, 240 — blue, and 360 yields red again; intermediate values yield hues such as cyan, magenta and yellow. Since H is a map input, its value can be controlled separately for different image areas by connecting a map component to this input.
S: Map Input
Defines the value of the Saturation channel in the range between 0 and 100. With the value of 0, the color is completely desaturated; with the value of 100, the color is most saturated. Since S is a map input, its value can be controlled separately for different image areas by connecting a map component to this input.
Defines the value of the lightness (Y) channel in the range between 0 and 100, reflecting the perception of color by a human eye. At 0, the color looks "very dark", though not actually black, and at 100 "very light", though not actually white. Since Y is a map input, its value can be controlled separately for different image areas by connecting a map component to this input. This input can accept HDR colors.
