Loading all images using imread from a given folder

Question

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

Answer 1

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

Answer 2

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)) 

Answer 3

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]

Answer 4

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)

Answer 5

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

Answer 6

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)