guides/object-cropping/

[giscus[bot]]

guides/object-cropping/

Learn how to isolate and extract specific objects from images and videos using YOLOv8 object cropping.

https://docs.ultralytics.com/guides/object-cropping/

[HsnKmlMt]

Hi! How can i specify classed to be cropped like for my case i just want people.

[HsnKmlMt]

Thank you, I really appreciate it!

[glenn-jocher]

Hello! We're really glad you found the materials helpful! If you ever need to specifically crop specific classes, such as 'people', you can do so by filtering the detections based on class IDs before cropping. Here's a quick example on how you might modify the example to only crop 'people':

from ultralytics import YOLO
import cv2
import os

model = YOLO("yolov8n.pt")  # Load your model
person_class_id = model.names.index('person')  # Assuming 'person' is the class name for people

cap = cv2.VideoCapture("path/to/video.mp4")
assert cap.isOpened(), "Error reading video file"

while cap.isOpened():
    ret, frame = cap.read()
    if not ret:
        break
    results = model.predict(frame)
    boxes = results.boxes.xyxy[results.boxes.cls == person_class_id].cpu().tolist()  # Filter detections to only 'person'

    for idx, box in enumerate(boxes):
        x1, y1, x2, y2 = map(int, box[:4])
        crop_img = frame[y1:y2, x1:x2]
        cv2.imwrite(f'cropped_person_{idx}.jpg', crop_img)

Feel free to replace 'person' with any class you're interested in, and make sure the class name matches what's defined in your model's class names. Let us know if you need further assistance! 🚀

[umairrkhn]

Hey Glenn,
I am getting this error using your implementation:

person_class_id = model.names.index('person') # Ensure 'person' is in the model's class names
^^^^^^^^^^^^^^^^^
AttributeError: 'dict' object has no attribute 'index'

[glenn-jocher]

Hey there!

It looks like you're trying to use the .index() method on a dictionary, which isn't supported. The model.names in YOLOv8 is a list, not a dictionary. Make sure that model.names is correctly referenced and is a list. Here’s how you can do it:

model = YOLO("yolov8n.pt")
person_class_id = model.names.index('person')  # This should work if model.names is a list

If model.names is somehow being altered to a dictionary in your code, you'll need to ensure it remains a list or adjust your approach accordingly. If the issue persists, could you share more of your code context? That might help diagnose the issue better. 😊

[glenn-jocher]

Hey there! It looks like you're trying to use the index() method on a dictionary, which isn't supported. The model.names is likely a dictionary, not a list. You can access the class index directly if you know the class name. Here’s how you can modify your code:

person_class_id = model.names['person']  # Directly access the 'person' class index

Make sure that 'person' is indeed the key for the class you're interested in. If model.names is structured differently, you might need to adjust the key accordingly. Let me know if this helps or if you need further assistance! 😊