OpenGait/docs/scoliosis_dataset_analysis_118_sharedalign.md

Scoliosis1K Dataset Analysis (1:1:8, shared-align skeleton maps)

Split

Train counts:

• negative: 596
• neutral: 74
• positive: 74

Test counts:

• negative: 204
• neutral: 126
• positive: 419

Raw pose quality

Mean keypoint confidence by split/class:

• train negative: 0.9016
• train neutral: 0.9023
• train positive: 0.8987
• test negative: 0.9009
• test neutral: 0.9020
• test positive: 0.8999

Mean valid-joint ratio (conf > 0.05) by split/class:

• train negative: 1.0000
• train neutral: 1.0000
• train positive: 1.0000
• test negative: 1.0000
• test neutral: 1.0000
• test positive: 1.0000

PAV signal

Mean normalized PAV value by label:

• negative: 0.3068
• neutral: 0.3546
• positive: 0.3635

Train-on-train / test-on-test linear softmax probe over sequence-level PAV:

• accuracy: 50.87%
• macro precision: 50.50%
• macro recall: 48.19%
• macro F1: 39.88%

Shared-align heatmap geometry

Combined support bbox stats over all sequences:

• width mean / p95: 32.13 / 33.57
• height mean / p95: 61.52 / 61.61
• active fraction mean / p95: 0.3634 / 0.3738

Per-sequence temporal jitter (std over frames):

• center-x std mean / p95: 0.864 / 1.243
• center-y std mean / p95: 0.516 / 0.704
• width std mean / p95: 2.152 / 2.804
• height std mean / p95: 0.507 / 0.545

Residual limb-vs-joint bbox-center mismatch after shared alignment:

• dx mean / p95: 0.195 / 0.229
• dy mean / p95: 0.251 / 0.357

Estimated intensity mass in the columns removed by BaseSilCuttingTransform:

• mean clipped-mass ratio: 0.0000
• p95 clipped-mass ratio: 0.0000

Reading

• The raw pose data does not look broken. Confidence and valid-joint ratios are high and similar across classes.
• The sequence-level PAV still carries useful label signal, so the dataset is not devoid of scoliosis information.
• Shared alignment removed the old limb-vs-joint registration bug; residual channel-center mismatch is now small.
• The remaining suspicious area is the visual branch: the skeleton map still has frame-to-frame bbox jitter, and the support bbox is almost full-height (~61.5 / 64) and fairly dense (~36% active pixels), which may be washing out subtle asymmetry cues.
• BaseSilCuttingTransform does not appear to be the main failure source for this shared-align export; the measured mass in the removed side margins is near zero.
• The dataset itself looks usable; the bigger issue still appears to be how the current skeleton-map preprocessing/runtime path presents that data to ScoNet.