Converting images to csv file in python

From your question, I think you want to know about numpy.flatten(). You want to add

value = value.flatten()

right before your np.savetxt call. It will flatten the array to only one dimension and it should then print out as a single line.

The rest of your question is unclear bit it implies you have a directory full of jpeg images and you want a way to read through them all. So first, get a file list:

def createFileList(myDir, format=".jpg"):
fileList = []
print(myDir)
for root, dirs, files in os.walk(myDir, topdown=False):
    for name in files:
        if name.endswith(format):
            fullName = os.path.join(root, name)
            fileList.append(fullName)
return fileList

The surround your code with a for fileName in fileList:

Edited to add complete example
Note that I’ve used csv writer and changed your float64 to ints (which should be ok as pixel data is 0-255

from PIL import Image
import numpy as np
import sys
import os
import csv

#Useful function
def createFileList(myDir, format=".jpg"):
fileList = []
print(myDir)
for root, dirs, files in os.walk(myDir, topdown=False):
    for name in files:
        if name.endswith(format):
            fullName = os.path.join(root, name)
            fileList.append(fullName)
return fileList

# load the original image
myFileList = createFileList('path/to/directory/')

for file in myFileList:
    print(file)
    img_file = Image.open(file)
    # img_file.show()

    # get original image parameters...
    width, height = img_file.size
    format = img_file.format
    mode = img_file.mode

    # Make image Greyscale
    img_grey = img_file.convert('L')
    #img_grey.save('result.png')
    #img_grey.show()

    # Save Greyscale values
    value = np.asarray(img_grey.getdata(), dtype=np.int).reshape((img_grey.size[1], img_grey.size[0]))
    value = value.flatten()
    print(value)
    with open("img_pixels.csv", 'a') as f:
        writer = csv.writer(f)
        writer.writerow(value)

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