Numpy 加载图像数据库时出错

当我运行这段代码时，即使我的图像显示为（208176），我也会得到一个ValueError，你知道为什么会这样吗？我对使用numpy不是很有经验

import os
import numpy as np
import pandas as pd
from skimage import io
from sklearn.linear_model import Perceptron

path = 'dataset'
directories = os.listdir(path)

df = pd.DataFrame()

for directory in directories:
    df = pd.DataFrame()
    for item in os.listdir(path + "/" + directory):
        pic = io.imread(path + "/" + directory + "/" + item)
        d = {"pic": pic, "type": directory}
        df = df.append(d, ignore_index=True)


# Create our X and y data
X = df['pic'].values
y = df['type'].values

# Create a Perceptron, with its training parameters
ppn = Perceptron(max_iter=40,tol=0.001,eta0=1)

ppn.fit(X,y)