1. What problem was solved:
Find the RGB of the color gradient between two colors.
2. Formula:
Gradient = A + (B-A) / Step * N
In order to improve efficiency and avoid floating-point operations during programming, the division is often placed at the end, so the formula becomes:Gradient = A + (B-A) * N / Step
Note : Gradient represents the R/G/B value of the Nth step, and A, B, and Step represent the gradient from color A to color B in Steps.
3. Calculation process:
Set Step=3, change the RGB(200,50,0) color gradient to RGB(50,200,0), that is: RGB(200,50,0) changes to RGB(50,200,0) after 3 color gradients
The 0th conversion, which is RGB(200,50,0) itself:
R0 = 200 + (50 - 200) / 3 * 0 = 200
G0 = 50 + (200 - 50) / 3 * 0 = 50
B0 = 0 + (0 - 0) / 3 * 0 = 0
RGB0 = (200, 50, 0)
1st conversion:
R1 = 200 + (50 - 200) / 3 * 1 = 150
G1 = 50 + (200 - 50) / 3 * 1 = 100
B1 = 0 + (0 - 0) / 3 * 1 = 0
RGB1 = (150, 100, 0)
2nd conversion:
R2 = 200 + (50 - 200) / 3 * 2 = 100
G2 = 50 + (200 - 50) / 3 * 2 = 150
B2 = 0 + (0 - 0) / 3 * 2 = 0
RBG2 = (100, 150, 0)
The third conversion, that is, the target color RGB(50,200,0):
R3 = 200 + (50 - 200) / 3 * 3 = 50
G3 = 50 + (200 - 50) / 3 * 3 = 200
B3 = 0 + ( 0 - 0) / 3 * 3 = 0
RBG3 = (50, 200, 0)
4. Code
import matplotlib.pyplot as plt
import numpy as np
step = 3 # 经过step步到达目标颜色
color_num = step + 1
one = np.ones(color_num)
from_rgb = (200,50,0) # 起始颜色
to_rbg = (50,200,0) # 目标颜色
colors = [((from_rgb[0] + (to_rbg[0]-from_rgb[0])/step*i),
(from_rgb[1] + (to_rbg[1]-from_rgb[1])/step*i),
(from_rgb[2] + (to_rbg[2]-from_rgb[2])/step*i))
for i in range(color_num)]
for index, color in enumerate(colors):
print(index, color)
colors = [((from_rgb[0] + (to_rbg[0]-from_rgb[0])/step*i) / 255,
(from_rgb[1] + (to_rbg[1]-from_rgb[1])/step*i) / 255,
(from_rgb[2] + (to_rbg[2]-from_rgb[2])/step*i) / 255)
for i in range(color_num)]
plt.pie(one, labels=range(color_num), colors=colors) # colors要求是0-1的浮点数
plt.show()
Results and color display:
Five, draw inferences about other cases from one instance
Next, modify the step, starting color, and target color , and subdivide the display of changes in more steps.
例1：
step = 50
from_rgb = (193, 214, 6)
to_rbg = (244, 225, 67)
例2：
step = 50
from_rgb = (244, 225, 67)
to_rbg = (227, 118, 0)
