It can convert rgb to lab, lab to rgb, rgb to hsl and hsl to rgb.
RGB：0...255
LAB：
L：Lightness 0...100
A: -128...127
B: -128...127
HSL:
h(float): hue 0...1
s(float): Saturation 0...1 (0=toward grey, 1=pure color)
l(float): Lightness 0...1 (0=black 0.5=pure color 1=white)
As we often need to convert the whole image colors, I also add matrix calculation so the speed could be very fast when we need to convert a lot of colors at once.
Single color conversion
import LAB
rgb=[123,245,211]
lab=LAB.rgb2lab(rgb)
rgb=LAB.lab2rgb(lab)Multi colors conversion
import LAB
import numpy as np
colors=np.random.randint(0,255,size=(900*600,3))
labs=LAB.rgb2lab_matrix(colors)
rgbs=LAB.lab2rgb_matrix(labs)Single color conversion
import HSL
rgb=[123,245,211]
hsl=HSL.rgb2hsl(rgb)
rgb=HSL.hsl2rgb(hsl)Multi colors conversion
import LAB
import numpy as np
colors=np.random.randint(0,255,size=(900*600,3))
hsls=LAB.rgb2hsl_matrix(colors)
rgbs=LAB.hsl2rgb_matrix(hsls)Time comparison
For n is 600*900, the time table is as follows. We can see using matrix calculation is much faster and it saves a lot of time.
| time | single for n times | matrix |
| -------- |:------------------:|:------:|
| rgb2lab | 5.923s | 0.234s |
| lab2rgb | 7.313s | 0.235s |
| | | |
| rgb2hsl | 4.782s | 0.156s |
| hsl2rgb | 3.249s | 0.140s |