Fix cutout bug

[Oswells]

Signed-off-by: Junjie Zhang 46258221+Oswells@users.noreply.github.com

When I use cutout, I find that even if the object is completely covered, its gt_label is still retained on the image.

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

Refinement of cutout augmentation in data preprocessing to enhance object detection.

📊 Key Changes

• Imported xywhn2xyxy function within augmentations.py.
• Improved the cutout function by ensuring it considers the IOA (Intersection over Area) of bounding boxes in the image coordinate space.

🎯 Purpose & Impact

• The purpose of these changes is to increase the accuracy of the cutout data augmentation technique used during training.
• By converting labels to the correct coordinate format before calculating IOA, it ensures that the object detection model is trained on better quality data, potentially leading to improved model performance.
• Users can expect their models to handle partial occlusions in a more robust way, which can be particularly beneficial for real-world applications where objects are often partially obscured.

[github-actions]

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[glenn-jocher]

@Oswells thanks for the PR! It looks like you are saying that the current box inputs are in the wrong format. Are you sure this is the case?

[Oswells]

Yes, I think the current box inputs are in the wrong format.
I use this code to check and it works well on yolov5:v6.1, but it may not be compatible with yolov5: v6.2. When I test it on yolov5:v6.2, I use v6.1's plot_images. I find that the latest version still exist this problem.

from utils.datasets import create_dataloader
from utils.general import colorstr,init_seeds
from utils.plots import plot_images
import yaml 

init_seeds(429)
hyp='data/hyps/hyp.scratch-low.yaml'
with open(hyp, errors='ignore') as f:
            hyp = yaml.safe_load(f)
dataloader, dataset = create_dataloader(  "test.txt",
                                            480,
                                            22 // 2,
                                            32,
                                            False,
                                            hyp=hyp,
                                            augment=True,
                                            cache="ram",
                                            rect=False,
                                            rank=-1,
                                            workers=4,
                                            image_weights=False,
                                            quad=False,
                                            prefix=colorstr('train: '),
                                            shuffle=False)
for imgs, targets, paths, _ in dataloader:
    plot_images(imgs,targets)

before：

fixed：

[glenn-jocher]

@Oswells I reviewed. You are absolutely right, the labels are in xywhn so the IoA computation is flawed.

Your fix looks good!

[glenn-jocher]

@Oswells PR is merged. Thank you for your contributions to YOLOv5 🚀 and Vision AI ⭐