ultralytics 8.4.168

v8.4.168 - ultralytics 8.4.168 Fix palette mask conversion, stale disk cache, AVIF orientation, same-stem predict outputs, and static-batch short inputs (#26443)

on Python PyPI

🌟 Summary

YOLO 8.4.168 delivers practical fixes for image and mask handling, prediction outputs, video timing, and exported models, alongside clearer training guidance. No model architecture changes are included.

📊 Key Changes

• 🖼️ More reliable image and mask processing: Palette PNG masks now retain their class IDs during conversion, 16-bit semantic masks preserve their IDs and flag invalid classes, and disk caches refresh when source images change.
• 🔄 Correct image orientation: AVIF images with EXIF orientation are read upright.
• 📁 No more overwritten prediction files: Images with the same filename stem, such as bus.jpg and bus.png, get distinct output names.
• 📦 Support for short inputs to fixed-batch exports: Inputs are padded to the required batch size and extra outputs are removed afterward.
• 🎥 Improved video handling: Fractional frame rates are preserved when reading videos, helping avoid playback timing drift.
• 🧩 Semantic-mask CutMix works as intended: CutMix can paste semantic-mask regions even when there are no object instances.
• 🧠 Quieter ReID setup: Re-identification models initialize embeddings with an in-memory image, avoiding a missing-source warning and unnecessary asset-image inference.
• 📚 Clearer training and platform guidance: Documentation now explains that mask_ratio affects training masks, while optimizer=auto ignores lr0; it also clarifies deployment rename behavior. CLI examples were adjusted accordingly.
• 🧪 Lighter similarity-search testing: SearchApp is tested using existing test images rather than triggering an extra large image download.

🎯 Purpose & Impact

• ✅ Reduces common data-handling errors that could cause incorrect labels, stale training images, or unexpected prediction-file overwrites.
• 🚀 Makes inference more dependable across fixed-batch exported models and varied image and video formats.
• 🎯 Helps semantic-segmentation users get the intended CutMix augmentation.
• 💡 Sets clearer expectations for training settings, so users are less likely to pass options such as lr0 that have no effect with the default automatic optimizer.

What's Changed

• Clarify mask_ratio does not change predicted mask resolution by @Y-T-G in #26441
• Warm the ReID predictor with an in-memory image by @raimbekovm in #26453
• Fold SearchApp init into the similarity search test to avoid a 32 MB download by @raimbekovm in #26452
• Correct optimizer=auto lr0/momentum docs and document deployment rename slug by @raimbekovm in #26447
• Fix CutMix skipping every paste on PNG semantic mask datasets by @Nikhi00718 in #26439
• Fix 16-bit semantic mask ids, CLI run name parsing, and fractional video fps by @Nicholas022400701 in #26440
• ultralytics 8.4.168 Fix palette mask conversion, stale disk cache, AVIF orientation, same-stem predict outputs, and static-batch short inputs by @cainiao33 in #26443

Full Changelog: v8.4.167...v8.4.168