任何人都知道一个很好的python算法,用于将HSV颜色转换为RGB(反之亦然),不依赖于任何外部模块?我正在研究一些动画生成代码,并希望支持HSV颜色空间,但是它在Raspberry Pi上运行,我试图避免任何浮点数.
解决方法:
此站点here将指导您完成各个步骤,包括如何使用整数除法.这里是一个描述RGB到HSV功能的python端口
def RGB_2_HSV(RGB):
''' Converts an integer RGB tuple (value range from 0 to 255) to an HSV tuple '''
# Unpack the tuple for readability
R, G, B = RGB
# Compute the H value by finding the maximum of the RGB values
RGB_Max = max(RGB)
RGB_Min = min(RGB)
# Compute the value
V = RGB_Max;
if V == 0:
H = S = 0
return (H,S,V)
# Compute the saturation value
S = 255 * (RGB_Max - RGB_Min) // V
if S == 0:
H = 0
return (H, S, V)
# Compute the Hue
if RGB_Max == R:
H = 0 + 43*(G - B)//(RGB_Max - RGB_Min)
elif RGB_Max == G:
H = 85 + 43*(B - R)//(RGB_Max - RGB_Min)
else: # RGB_MAX == B
H = 171 + 43*(R - G)//(RGB_Max - RGB_Min)
return (H, S, V)
与colorsys函数相比,这给出了正确的结果
import colorsys
RGB = (127, 127, 127)
Converted_2_HSV = RGB_2_HSV(RGB)
Verify_RGB_2_HSV = colorsys.rgb_to_hsv(RGB[0], RGB[1], RGB[2])
print Converted_2_HSV
>>> (0, 0, 127)
print Verify_RGB_2_HSV # multiplied by 255 to bring it into the same scale
>>> (0.0, 0.0, 127.5)
你可以检查输出是否仍然是一个整数
type(Converted_2_HSV[0])
>>> <type 'int'>
现在为反向功能.原始源可以找到here,这是Python端口.
def HSV_2_RGB(HSV):
''' Converts an integer HSV tuple (value range from 0 to 255) to an RGB tuple '''
# Unpack the HSV tuple for readability
H, S, V = HSV
# Check if the color is Grayscale
if S == 0:
R = V
G = V
B = V
return (R, G, B)
# Make hue 0-5
region = H // 43;
# Find remainder part, make it from 0-255
remainder = (H - (region * 43)) * 6;
# Calculate temp vars, doing integer multiplication
P = (V * (255 - S)) >> 8;
Q = (V * (255 - ((S * remainder) >> 8))) >> 8;
T = (V * (255 - ((S * (255 - remainder)) >> 8))) >> 8;
# Assign temp vars based on color cone region
if region == 0:
R = V
G = T
B = P
elif region == 1:
R = Q;
G = V;
B = P;
elif region == 2:
R = P;
G = V;
B = T;
elif region == 3:
R = P;
G = Q;
B = V;
elif region == 4:
R = T;
G = P;
B = V;
else:
R = V;
G = P;
B = Q;
return (R, G, B)
我们可以像以前一样验证结果
interger_HSV = (127, 127, 127)
Converted_2_RGB = HSV_2_RGB(interger_HSV)
Verify_HSV_2_RGB = colorsys.hsv_to_rgb(0.5, 0.5, 0.5)
print Converted_2_RGB
>>> (63, 127, 124)
print type(Converted_2_RGB[0])
>>> <type 'int'>
print Verify_HSV_2_RGB # multiplied these by 255 so they are on the same scale
>>> (63.75, 127.5, 127.5)
整数算法确实会引入一些错误,但是根据应用程序的不同,这些错误可能会正常.