Python Read multiple images from multiple folders

Question

I want to read multiple .jpg images, that are in 3 separate folders. The 3 folders are on the same path. I tried to do it like this:

path1 = os.path.abspath('Type_1')
path2 = os.path.abspath('Type_2')
path3 = os.path.abspath('Type_3')
folder = os.path.join(path1, path2, path3)

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

print(load_images_from_folder(folder))

But it only returns the last path and not all of them. I also tried to use relative paths, such as:

path1 = os.path.relpath('Type_1')
path2 = os.path.relpath('Type_2')
path3 = os.path.relpath('Type_3')
folder = os.path.join(os.path.sep, path1, path2, path3)

but still the same problem. Can someone help with this?

khelwood · Accepted Answer · 2017-05-17 12:05:45Z

4

Your return images line is inside your loop, so it will return as soon as it finds any matching result. You only want it to return after the whole loop as finished.

Reduce the indentation of the return statement so that it lies after the loop instead of inside it.

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

[Edit]

If you want to look in multiple adjacent folders, you want something like this:

root_folder = '[whatever]/data/train'
folders = [os.path.join(root_folder, x) for x in ('Type_1', 'Type_2', 'Type_3')]
all_images = [img for folder in folders for img in load_images_from_folder(folder)]

That will call load_images on each folder, and put all the results into one list.

edited May 17, 2017 at 12:05

answered May 16, 2017 at 13:21

khelwood

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4 Comments

joasa Over a year ago

actually i realized that it still doesn't work. when i print(len(load_images_from_folder(folder))) it returns the number of images located at path3 and not at folder

joasa Over a year ago

NameError: name 'folders' is not defined

joasa Over a year ago

Also, if I want to define path1 as a path referring to a parent directory, is this way correct, or is there a more flexible/smart solution? path1 = os.path.abspath('..\\data\\train\\Type_1')

khelwood Over a year ago

@joasa My code does not produce name 'folders' is not defined'. It's defined right there.

initialed85 · Accepted Answer · 2017-05-18 03:19:24Z

3

If I understand the problem correctly, your file structure looks as follows:

- Type1
    - Image1.jpg
    - Image2.jpg
- Type2
    - Image1.jpg
    - Image2.jpg
- Type3
    - Image1.jpg
    - Image2.jpg

If this is true, then the os.path.join call is errant (it'll result in a string that reads "Type1/Type2/Type3" which achieves nothing for you).

I think the code you're looking for is as follows:

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

folders = [
    'Type1',
    'Type2',
    'Type3',
]

for folder in folders:
    images = load_images_from_folder(folder)
    # your code that does something with the return images goes here

edited May 18, 2017 at 3:19

answered May 16, 2017 at 13:28

initialed85

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2 Comments

joasa Over a year ago

Ok, I tried that but when I do print(len(images)) it returns: 1 1 1 (vertically) instead of the total number of images in folder. I guess it means that it sees only one image per path? But why is that?

initialed85 Over a year ago

Ah, my bad there- the return is indented too far. Drop that back so it's inline with the for (as per your original code snippet) and it should be good.

Sadiq · Accepted Answer · 2021-05-09 19:53:05Z

0

I know this is really old, but this worked for me recently.

 def create_dataset(img_folder):
    img_data_array=[]
    class_name=[]

    for dirl in os.listdir(img_folder):
        for file in os.listdir(os.path.join(img_folder,dirl)):
        
            if any([file.endswith(x) for x in ['.jpeg', '.jpg']]):
            

                 image_path=os.path.join(img_folder,dirl,file)
                 image=cv2.imread(image_path,cv2.COLOR_BGR2RGB)
             
                 img_data_array.append(image)
                 class_name.append(dirl)
    return img_data_array,class_name


img_data, class_name =create_dataset(train_folder)

answered May 9, 2021 at 19:53

Sadiq

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