Dataset quality guide
How to validate segmentation masks without uploading the dataset
Check masks and polygons locally before segmentation training.
Validate shape and bounds
A polygon needs usable points and must stay within the image. A malformed mask is not a harmless warning.
Check image pairing
A valid mask still fails its job if it belongs to the wrong image or uses inconsistent dimensions.
Preserve the source
Review local findings and retain the original export while applying corrections.
Decide what blocks training
Set the decision rule before reading the report. Invalid annotations, missing media, split leakage, and incomplete coverage should block a training run until a reviewer resolves or deliberately accepts them. Less severe findings can still matter, but they need a documented disposition instead of being buried under a single aggregate score. The matching solution page explains which local checks apply to this dataset shape and why the result is limited when evidence is unavailable.
Keep evidence with the dataset revision
Save the local report, quality profile, and repair manifest beside the dataset version that entered training. That record lets a teammate reproduce the same finding, compare a later export, and distinguish a data change from a model change. A report is evidence from configured checks at a point in time. It is not a guarantee of model performance or an independent certification.
Repeat the check after every material change
Run the same local check again after relabeling, changing class mappings, moving images between splits, or accepting a vendor correction. Rechecking is more useful than carrying a historical score forward because the score only describes the records and coverage that were examined. For scripted review, keep the quality command and threshold in the training repository so a new dataset revision receives the same gate.
Check your dataset locally
Use the matching local check before starting a training run.