Faster crop saving

[glenn-jocher]

Avoids cv2 calls for BGR to RGB per #8641 (comment)

🛠️ PR Summary

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🌟 Summary

Improved image saving in YOLOv5 by fixing color issues.

📊 Key Changes

• Altered the method used for saving images to maintain the correct color format (RGB).

🎯 Purpose & Impact

• The changes ensure that when images are saved, they retain their original color presentation without any chroma subsampling issues.
• Users of YOLOv5 will experience more accurate color representation in saved images, which is particularly important for image processing tasks where color information is crucial. 🎨✅