mlib_ImageColorRGB2HSV(3MLIB) mediaLib Library Functions mlib_ImageColorRGB2HSV(3MLIB)
NAME
mlib_ImageColorRGB2HSV - RGB to HSV color conversion
SYNOPSIS
cc [ flag... ] file... -lmlib [ library... ]
#include <mlib.h>
mlib_status mlib_ImageColorRGB2HSV(mlib_image *dst, const mlib_image *src);
DESCRIPTION
The mlib_ImageColorRGB2HSV() function performs a conversion from red/green/blue to hue/saturation/value. The source and destination images
must be three-channel images.
It uses the following equations:
V = max(R, G, B)
Vmin = min(R, G, B)
S = (V - Vmin)/V
H = (5.0 + (V - B)/(V - Vmin))/6 if R = V and G = Vmin
H = (1.0 - (V - G)/(V - Vmin))/6 if R = V and B = Vmin
H = (1.0 + (V - R)/(V - Vmin))/6 if G = V and B = Vmin
H = (3.0 - (V - B)/(V - Vmin))/6 if G = V and R = Vmin
H = (3.0 + (V - G)/(V - Vmin))/6 if B = V and R = Vmin
H = (5.0 - (V - R)/(V - Vmin))/6 if B = V and G = Vmin
H = 0.0 if R = G = B
where 0 <= R, G, B, V, Vmin, S <= 1 and 0 <= H < 1.
Assuming a pixel in the source image is (r, g, b) and its corresponding pixel in the destination image is (h, s, v), then for MLIB_BYTE
images, the following applies:
R = r/255
G = g/255
B = b/255
h = H*256
s = S*255
v = V*255
for MLIB_SHORT images, the following applies:
R = (r + 32768)/65535
G = (g + 32768)/65535
B = (b + 32768)/65535
h = H*65536 - 32768
s = S*65535 - 32768
v = V*65535 - 32768
for MLIB_USHORT images, the following applies:
R = r/65535
G = g/65535
B = b/65535
h = H*65536
s = S*65535
v = V*65535
and for MLIB_INT images, the following applies:
R = (r + 2147483648)/4294967295
G = (g + 2147483648)/4294967295
B = (b + 2147483648)/4294967295
h = H*4294967296 - 2147483648
s = S*4294967295 - 2147483648
v = V*4294967295 - 2147483648
PARAMETERS
The function takes the following arguments:
dst Pointer to destination image.
src Pointer to source image.
RETURN VALUES
The function returns MLIB_SUCCESS if successful. Otherwise it returns MLIB_FAILURE.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Interface Stability |Committed |
+-----------------------------+-----------------------------+
|MT-Level |MT-Safe |
+-----------------------------+-----------------------------+
SEE ALSO
mlib_ImageColorHSV2RGB(3MLIB), mlib_ImageColorHSV2RGB_Fp(3MLIB), mlib_ImageColorRGB2HSV_Fp(3MLIB), attributes(5)
SunOS 5.11 2 Mar 2007 mlib_ImageColorRGB2HSV(3MLIB)