'Read Multiple images on a folder in OpenCv (python)

I want to read multiple images on a same folder using opencv (python). To do that do I need to use for loop or while loop with imread funcion? If so, how? please help me...

I want to get images into an array and then processed them one at a time through a loop.

python-2.7opencvimage-processing


Solution 1:[1]

import glob
import cv2

images = [cv2.imread(file) for file in glob.glob("path/to/files/*.png")]

Solution 2:[2]

This will get all the files in a folder in onlyfiles. And then it will read them all and store them in the array images.

from os import listdir
from os.path import isfile, join
import numpy
import cv2

mypath='/path/to/folder'
onlyfiles = [ f for f in listdir(mypath) if isfile(join(mypath,f)) ]
images = numpy.empty(len(onlyfiles), dtype=object)
for n in range(0, len(onlyfiles)):
  images[n] = cv2.imread( join(mypath,onlyfiles[n]) )

Solution 3:[3]

import glob
import cv2 as cv

path = glob.glob("/path/to/folder/*.jpg")
cv_img = []
for img in path:
    n = cv.imread(img)
    cv_img.append(n)

Solution 4:[4]

This one has better time efficiency.

def read_img(img_list, img):
    n = cv2.imread(img, 0)
    img_list.append(n)
    return img_list

path = glob.glob("*.bmp") #or jpg
list_ = []`

cv_image = [read_img(list_, img) for img in path]

Solution 5:[5]

import cv2
from pathlib import Path

path=Path(".")

path=path.glob("*.jpg")

images=[]`


for imagepath in path.glob("*.jpg"):

        img=cv2.imread(str(imagepath))
        img=cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)                         
        img=cv2.resize(img,(200,200))
        images.append(img)
print(images)

Solution 6:[6]

def flatten_images(folder): # Path of folder (dataset)

images=[]                             # list contatining  all images

for filename in os.listdir(folder):

    print(filename)

    img=plt.imread(folder+filename)  # reading image (Folder path and image name )

    img=np.array(img)                #

    img=img.flatten()                # Flatten image 

    images.append(img)               # Appending all images in 'images' list 

return(images)

Solution 7:[7]

Here is how I did it without using glob, but with using the os module instead, since I could not get it to work with glob on my computer:

# This is to get the names of all the files in the desired directory
# Here I assume that they are all images
original_images = os.listdir('./path/containing/images')

# Here I construct a list of relative path strings for each image
original_images = [f"./path/containing/images/{file_name}" for file_name in original_images]

original_images = [cv2.imread(file) for file in original_images]

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution Source
Solution 1 Soufiane S
Solution 2
Solution 3 Felipe Weber
Solution 4 Shivaraj
Solution 5 Eric Aya
Solution 6 Dhiren Biren
Solution 7

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