RGBHSV

RGBHSV refers to the relationship between the RGB and HSV color models in digital imaging. RGB represents colors as a mix of red, green, and blue light, typically with integer components in the range 0 to 255 on 8-bit channels. HSV, also known as HSB, expresses color in terms of hue (the type of color, usually 0 to 360 degrees), saturation (colorfulness, 0 to 1 or 0 to 100%), and value or brightness (0 to 1 or 0 to 100%). The two models serve different purposes: RGB aligns with how displays mix light, while HSV aligns more closely with human color perception and intuitive color selection.

Conversions between RGB and HSV are routinely performed in graphics, image processing, and computer vision. In RGB space, normalize r, g, b to the range 0–1. Let max = max(r, g, b), min = min(r, g, b), and d = max − min. Value V equals max. If max is zero, saturation S is zero; otherwise S = d / max. Hue H is defined only when d > 0 and depends on which channel is the maximum:

- if max = r, H = (g − b) / d + (g < b ? 6 : 0)

- if max = g, H = (b − r) / d + 2

- if max = b, H = (r − g) / d + 4

Then H is multiplied by 60 to convert to degrees. For HSV to RGB, compute C = V × S, X = C × (1 − |(H/60) mod 2 − 1|), m = V − C, and map (C, X, 0) permutations to RGB, then add m and scale to 0–255.

Applications include color pickers, image editing, and color-based segmentation. Limitations include non-perceptual uniformity of HSV and potential clipping or rounding errors during conversion.