[python] Loading all images using imread from a given folder

Loading and saving images in OpenCV is quite limited, so... what is the preferred ways to load all images from a given folder? Should I search for files in that folder with .png or .jpg extensions, store the names and use imread with every file? Or is there a better way?

import os
import cv2
rootdir = "directory path"
for subdir, dirs, files in os.walk(rootdir):
    for file in files:
        frame = cv2.imread(os.path.join(subdir, file)) 

You can also use matplotlib for this, try this out:

import matplotlib.image as mpimg

def load_images(folder):
    images = []
    for filename in os.listdir(folder):
        img = mpimg.imread(os.path.join(folder, filename))
        if img is not None:
            images.append(img)
    return images

you can use glob function to do this. see the example

import cv2
import glob
for img in glob.glob("path/to/folder/*.png"):
    cv_img = cv2.imread(img)

To add onto the answer from Rishabh and make it able to handle files that are not images that are found in the folder.

import matplotlib.image as mpimg

images = []
folder = './your/folder/'
for filename in os.listdir(folder):
    try:
        img = mpimg.imread(os.path.join(folder, filename))
        if img is not None:
            images.append(img)
    except:
        print('Cant import ' + filename)
images = np.asarray(images)

If all images are of the same format:

import cv2
import glob

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

For reading images of different formats:

import cv2
import glob

imdir = 'path/to/files/'
ext = ['png', 'jpg', 'gif']    # Add image formats here

files = []
[files.extend(glob.glob(imdir + '*.' + e)) for e in ext]

images = [cv2.imread(file) for file in files]

Why not just try loading all the files in the folder? If OpenCV can't open it, oh well. Move on to the next. cv2.imread() returns None if the image can't be opened. Kind of weird that it doesn't raise an exception.

import cv2
import os

def load_images_from_folder(folder):
    images = []
    for filename in os.listdir(folder):
        img = cv2.imread(os.path.join(folder,filename))
        if img is not None:
            images.append(img)
    return images

import glob
cv_img = []
for img in glob.glob("Path/to/dir/*.jpg"):
    n= cv2.imread(img)
    cv_img.append(n)`

I used skimage. You can create a collection and access elements the standard way, i.e. col[index]. This will give you the RGB values.

from skimage.io import imread_collection

#your path 
col_dir = 'cats/*.jpg'

#creating a collection with the available images
col = imread_collection(col_dir)