使用 numpy 在 python 上创建图像答案

【问题标题】：Create an image on python with numpy使用 numpy 在 python 上创建图像
【发布时间】：2021-07-24 14:22:51
【问题描述】：

我正在尝试在 python 3.7（在 Thonny）上创建图像。我想用灰度值设置一个矩阵，所以 0 是黑色，255 是白色。该矩阵将代表我要创建的图像的像素。基本上，我想基于矩阵创建黑白图像。这是我的代码：

from PIL import Image
import numpy as np


largeur = 2
hauteur = 2
couleur = 'L'


im = Image.new(couleur, (largeur, hauteur))
matrice = np.array([[0,255],[255,0]])
for x in range(largeur):
    for y in range(hauteur):
        a = int()
        a = matrice[x,y]
        print(a)
        im.putpixel((x, y), (a))    # Composante R en fonction de la hauteur


im.save('Degrade.jpg')
im.show()

当我运行程序时，它说 a 是问题：“颜色必须是 int 或元组”。

感谢您的帮助，祝您有愉快的一天！

我试过 Image.fromarray ：

from PIL import Image
import numpy as np


largeur = 50
hauteur = 8
couleur = 'L'


#im = Image.new(couleur, (largeur, hauteur))
matrice = np.array([[255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255],
[255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255],
[255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255],
[255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255],
[255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255],
[255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255],
[255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255],
[255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255]])
#for x in range(largeur):
    #for y in range(hauteur):
        #a = int()
        #a = matrice[x,y]
        #print(a)
        #im.putpixel((x, y), (255)) # Composante R en fonction de la hauteur

im = Image.fromarray(matrice, mode=couleur)
im.save('Degrade.jpg')
im.show()

有了这个，我应该有一个只有白色像素的 50 x 8 像素的图像，但我得到了白色和黑色像素（看下面的图片），我知道我们看不到太多抱歉 :) 也非常感谢为您解答：

【问题讨论】：

标签： python image numpy matrix python-imaging-library

【解决方案1】：

你可以尝试使用Image.fromarray：

Image.fromarray(matrice, mode=couleur)

【讨论】：

非常感谢您的回答，我已经尝试过这个解决方案，但出现了另一个问题。

【解决方案2】：

对不起，我的长期回答。问题在于正在使用的类型并将其转换为图像。如果对图像使用单字节类型，则矩阵类型也必须是单字节。示例：

from PIL import Image
import numpy as np

size_x = 50
size_y = 8
m = "L"

matrix = np.array([[255] * 50 for _ in range(size_y)], dtype="uint8")
im = Image.fromarray(matrix, mode=m)

im.save('Degrade.jpg')
im.show()

【讨论】：