local p = {}
function rgb2hsv(r, g, b)
local max = math.max(r, g, b)
local min = math.min(r, g, b)
local c = max - min
-- calculate hue
local h
if c == 0 then
h = 0
elseif max == r then
h = 60 * (0 + ((g - b)/c))
elseif max == g then
h = 60 * (2 + ((g - b)/c))
elseif max == b then
h = 60 * (4 + ((g - b)/c))
end
if h < 0 then h = h + 360 end
-- calculate value
local v = max
-- calculate luminance
-- local l = (max + min) / 2
-- calculate saturation
local s
if c == 0 then
s = 0
else
s = c/v
end
return h, s, v
end
function hsv2rgb(h, s, v)
local hi = math.floor(h / 60)
local f = ((h / 60) - hi)
local p = v * (1 - s)
local q = v * (1 - s * f)
local t = v * (1 - s * (1 - f))
if hi == 1 then
return q, v, p
elseif hi == 2 then
return p, v, t
elseif hi == 3 then
return p, q, v
elseif hi == 4 then
return t, p, v
elseif hi == 5 then
return v, p, q
else
return v, t, p
end
end
--[[ toHSV
Description: Converts a RGB color to a HSV color.
Usage: {{#invoke:HSV|toHSV|R|G|B}}
Output: hue [0°..360°], saturation [0..1], value [0..1] ]] function p.toHSV(frame)
return rgb2hsv(frame.args[1] / 255, frame.args[2] / 255, frame.args[3] / 255)
end
--[[ toHSV
Description: Returns the hue of a RGB color.
Usage: {{#invoke:HSV|hue|R|G|B}}
Output: hue [0°..360°] ]] function p.hue(frame)
local h, s, v = rgb2hsv(frame.args[1] / 255, frame.args[2] / 255, frame.args[3] / 255) return h
end
--[[ toHSV
Description: Returns the saturation of a RGB color.
Usage: {{#invoke:HSV|saturation|R|G|B}}
Output: saturation [0..1] ]] function p.saturation(frame)
local h, s, v = rgb2hsv(frame.args[1] / 255, frame.args[2] / 255, frame.args[3] / 255) return s
end
--[[ toHSV
Description: Returns the saturation of a RGB color.
Usage: {{#invoke:HSV|saturation|R|G|B}}
Output: saturation [0..1] ]] function p.saturate(frame)
local h, s, v = rgb2hsv(frame.args[1] / 255, frame.args[2] / 255, frame.args[3] / 255) return s
end
--[[ toHSV
Description: Returns the hue of a RGB color.
Usage: {{#invoke:HSV|value|R|G|B}}
Output: value [0..1] ]] function p.value(frame)
local h, s, v = rgb2hsv(frame.args[1] / 255, frame.args[2] / 255, frame.args[3] / 255) return v
end
--[[ toHSV
Description: Saturates a RGB color by a given factor.
Usage: {{#invoke:HSV|saturate|R|G|B|factor}}
Output: saturated RGB ]] function p.saturate(frame)
-- convert to HSV
local h, s, v = rgb2hsv(frame.args[1] / 255, frame.args[2] / 255, frame.args[3] / 255)
-- saturate
s = s * frame.args[4]
if s < 0 then
s = 0
elseif s > 1 then
s = 1
end
-- convert back to RGB
local r, g, b = hsv2rgb(h, s, v)
return math.floor(r * 255 + 0.5), math.floor(g * 255 + 0.5), math.floor(b * 255 + 0.5)
end
--[[ toHSV
Description: Converts a HSV color to a RGB color.
Usage: {{#invoke:HSV|toRGB|H|S|V}} with H in [0°..360°], S in [0..1] and V in [0..1]
Output: R, G, B ]] function p.toRGB(frame)
local r, g, b = hsv2rgb(frame.args[1], frame.args[2], frame.args[3]) -- transform from real [0..1] to integer [0..255] return math.floor(r * 255 + 0.5), math.floor(g * 255 + 0.5), math.floor(b * 255 + 0.5)
end
return p