python - 在 matplotlib 中仅绘制一种 rgb 颜色

Question

我正在运行 matplotlib，我想绘制一种颜色，例如:

import matplotlib.pyplot as plt
plt.imshow([(100, 100, 200)])

但这显示了渐变。什么问题？

Answer 1

这只给出一种颜色:

import matplotlib.pyplot as plt
plt.imshow([[(0, 0, 1)]])

plt.imshow([[(0.5, 0.5, 0.5)]])

你需要一个 MxNx3 的形状:

>>> import numpy as np
>>> np.array([[(0.5, 0.5, 0.5)]]).shape
(1, 1, 3)

这里M和N都是1。

plt.imshow(X, ...)

X : array_like, shape (n, m) or (n, m, 3) or (n, m, 4) Display the image in X to current axes. X may be a float array, a uint8 array or a PIL image. If X is an array, it can have the following shapes:

• MxN -- luminance (grayscale, float array only)
• MxNx3 -- RGB (float or uint8 array)

• MxNx4 -- RGBA (float or uint8 array)

  The value for each component of MxNx3 and MxNx4 float arrays should be in the range 0.0 to 1.0; MxN float arrays may be normalized.

您需要将 0 和 1 之间的 int 转换为 float:

from __future__ import division  # needed for Python 2 only

plt.imshow([[(100 / 255, 100 / 255, 200 / 255)]])