mlib_ImageColorRGB2HSL(3mlib)

1mlib_ImageColorRGB2HSL(3MLImBe)diaLib Library Functiomnlsib_ImageColorRGB2HSL(3MLIB)
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NAME

6       mlib_ImageColorRGB2HSL - RGB to HSL color conversion
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SYNOPSIS

9       cc [ flag... ] file... -lmlib [ library... ]
10       #include <mlib.h>
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12       mlib_status mlib_ImageColorRGB2HSL(mlib_image *dst, const mlib_image *src);
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DESCRIPTION

16       The   mlib_ImageColorRGB2HSL()  function  performs  a  conversion  from
17       red/green/blue to hue/saturation/lightness. The source and  destination
18       images must be three-channel images.
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21       It uses the following equations:
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23            V = max(R, G, B)
24         Vmin = min(R, G, B)
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26            L = (V + Vmin)/2
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28            S = (V - Vmin)/(V + Vmin)         if L ≤ 1/2
29            S = (V - Vmin)/(2 - V - Vmin)     if L > 1/2
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31            H = (5.0 + (V - B)/(V - Vmin))/6  if R = V and G = Vmin
32            H = (1.0 - (V - G)/(V - Vmin))/6  if R = V and B = Vmin
33            H = (1.0 + (V - R)/(V - Vmin))/6  if G = V and B = Vmin
34            H = (3.0 - (V - B)/(V - Vmin))/6  if G = V and R = Vmin
35            H = (3.0 + (V - G)/(V - Vmin))/6  if B = V and R = Vmin
36            H = (5.0 - (V - R)/(V - Vmin))/6  if B = V and G = Vmin
37            H = 0.0                           if R = G = B
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41       where 0 ≤ R, G, B, V, Vmin, L, S ≤ 1 and 0 ≤ H < 1.
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44       Assuming a pixel in the source image is (r, g, b) and its corresponding
45       pixel in the destination image is (h, s, l), then for MLIB_BYTE images,
46       the following applies:
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48            R = r/255
49            G = g/255
50            B = b/255
51            h = H*256
52            s = S*255
53            l = L*255
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57       for MLIB_SHORT images, the following applies:
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59            R = (r + 32768)/65535
60            G = (g + 32768)/65535
61            B = (b + 32768)/65535
62            h = H*65536 - 32768
63            s = S*65535 - 32768
64            l = L*65535 - 32768
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68       for MLIB_USHORT images, the following applies:
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70            R = r/65535
71            G = g/65535
72            B = b/65535
73            h = H*65536
74            s = S*65535
75            l = L*65535
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79       and for MLIB_INT images, the following applies:
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81            R = (r + 2147483648)/4294967295
82            G = (g + 2147483648)/4294967295
83            B = (b + 2147483648)/4294967295
84            h = H*4294967296 - 2147483648
85            s = S*4294967295 - 2147483648
86            l = L*4294967295 - 2147483648
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PARAMETERS

90       The function takes the following arguments:
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92       dst    Pointer to destination image.
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95       src    Pointer to source image.
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RETURN VALUES

99       The  function  returns MLIB_SUCCESS if successful. Otherwise it returns
100       MLIB_FAILURE.
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ATTRIBUTES

103       See attributes(5) for descriptions of the following attributes:
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108       ┌─────────────────────────────┬─────────────────────────────┐
109       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
110       ├─────────────────────────────┼─────────────────────────────┤
111       │Interface Stability          │Committed                    │
112       ├─────────────────────────────┼─────────────────────────────┤
113       │MT-Level                     │MT-Safe                      │
114       └─────────────────────────────┴─────────────────────────────┘
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NAME

SYNOPSIS

DESCRIPTION

PARAMETERS

RETURN VALUES

ATTRIBUTES

SEE ALSO