How to display image stored in pandas dataframe?

Question

import pandas as pd
from scipy import misc
import numpy as np
import matplotlib.pyplot as plt

W = {\'img\':[misc.imread(\'pic.jpg\')]}
df = pd.DataFrame(W)

# This disp         


        

Answer 1

It is not clear from the question why you would want to use pandas dataframes to store the image. I think this makes things unnecessarily complicated. You may instead directly store the numpy array in binary format and load it again at some point later.

import numpy as np
import matplotlib.pyplot as plt

#create an image
imar = np.array([[[1.,0.],[0.,0.]],
                 [[0.,1.],[0.,1.]],
                 [[0.,0.],[1.,1.]]]).transpose()
plt.imsave('pic.jpg', imar)

# read the image
im = plt.imread('pic.jpg')
# show the image
plt.imshow(im)
plt.show()

#save the image array to binary file
np.save('mypic', im)
# load the image from binary file
new_im= np.load('mypic.npy')
# show the loaded image
plt.imshow(new_im)
plt.show()

As a response to the comments below, which turn the question somehow in a different direction, you may surely store the path/name of the image in the dataframe.

import pandas as pd
import numpy as np
import matplotlib.pyplot as plt

#create an image
imar = np.array([[[1.,0.],[0.,0.]],
                 [[0.,1.],[0.,1.]],
                 [[0.,0.],[1.,1.]]]).transpose()
plt.imsave('pic.jpg', imar)

#create dataframe

df = pd.DataFrame([[0,""]], columns=["Feature1","Feature2"])

# read the image
im = plt.imread('pic.jpg')

plt.imshow(im)
plt.show()

#save the image array to binary file
np.save('mypic.npy', im)
# store name of image in dataframe
df.iloc[0,1] = 'mypic.npy'
#save dataframe
df.to_csv("mydf.csv")
del df

#read dataframe from csv
df = pd.read_csv("mydf.csv")
# load the image from binary file, given the path from the Dataframe
new_im= np.load(df["Feature2"][0])
# show the loaded image
plt.imshow(new_im)
plt.show()

Last, you may go along the initally planned way of storing the actual image in a dataframe cell, but instead of writing to csv, you map pickle the dataframe, such that it can be read out just as if it had never been saved before.

import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
import pickle

#create an image
imar = np.array([[[1.,0.],[0.,0.]],
                 [[0.,1.],[0.,1.]],
                 [[0.,0.],[1.,1.]]]).transpose()
plt.imsave('pic.jpg', imar)

#create dataframe

df = pd.DataFrame([[0,""]], columns=["Feature1","Feature2"])

# read the image
im = plt.imread('pic.jpg')

plt.imshow(im)
plt.show()

# store the image itself  in dataframe
df.iloc[0,1] = [im]
#save dataframe
pickle.dump(df, file("mydf.pickle", "wb"))
del df

#read dataframe from pickle
df = pickle.load(file("mydf.pickle", "rb"))

# show the loaded image from dataframe cell
plt.imshow(df["Feature2"][0][0])
plt.show()