Python Convert Image (JPG, PNG) to CSV

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Given an image as a .png or .jpeg file. How to convert it to a CSV file in Python?

Example image:

Convert the image to a CSV using the following steps:

  1. Read the image into a PIL.Image object.
  2. Convert the PIL.Image object to a 3D NumPy array with the dimensions rows, columns, and RGB values.
  3. Convert the 3D NumPy array to a 2D list of lists by collapsing the RGB values into a single value (e.g., a string representation).
  4. Write the 2D list of lists to a CSV using normal file I/O in Python.

Here’s the code that applies these four steps, assuming the image is stored in a file named 'c++.jpg':

from PIL import Image
import numpy as np


# 1. Read image
img = Image.open('c++.jpg')
 
# 2. Convert image to NumPy array
arr = np.asarray(img)
print(arr.shape)
# (771, 771, 3)

# 3. Convert 3D array to 2D list of lists
lst = []
for row in arr:
    tmp = []
    for col in row:
        tmp.append(str(col))
    lst.append(tmp)


# 4. Save list of lists to CSV
with open('my_file.csv', 'w') as f:
    for row in lst:
        f.write(','.join(row) + '\n')

Note that the resulting CSV file looks like this with super long rows.

Each CSV cell (column) value is a representation of the RGB value at that specific pixel. For example, [255 255 255] represents the color white at that pixel.

For more information and some background on file I/O, check out our detailed tutorial on converting a list of lists to a CSV:

🌍 Related Tutorial: How to Convert a List to a CSV File in Python [5 Ways]