2.0.15

Summary

This PR significantly improves the flatbuffer_direct path, focusing on conversion stability, quantization-chain optimizations, shape/NHWC propagation, and redundant transpose reduction.

• Changed files: 37
• Diffstat: +7283 / -493
• Base commit (main): 9281976
• Head commit (fix-var): 2d9ca0a

Main Changes

1. FlatBuffer direct lowering and shape propagation

• Strengthened shape / shape_signature propagation, mainly in lower_from_onnx2tf.py.
• Reduced shape-freezing issues in dynamic-shape cases. <img width="716" height="492" alt="image" src="https://github.com/user-attachments/assets/d6f22ad5-7564-485f-937e-67ca48173054" />
• Expanded redundant Transpose-chain elimination around NCHW/NHWC bridges.
• Improved shape consistency around Resize*, Conv, DepthwiseConv, ConvTranspose, Mean, Squeeze, and Concat.

1. Quantized chain optimizations

• Added/extended folds for:
  • Dequantize -> HardSigmoid -> Quantize
  • Dequantize -> TransposeConv -> Quantize
  • Dequantize -> Reshape -> Quantize
  • Dequantize -> MaxPool -> Quantize
  • Dequantize -> Softmax -> Quantize
• Improved robustness for QLinear-family ops, including QLinearConv, QLinearConcat, QLinearAdd, QLinearMul, and QLinearSigmoid.

1. Preprocess pipeline improvements

• Added new rule: bn_fold_wave0 (preprocess/rules/bn_fold.py)
  • Conv/ConvTranspose + BatchNormalization fold
  • affine expansion for Dequantize + BatchNormalization
  • new fold for Conv -> Mul -> Add affine chains
• Added new rule: cleanup_unused_initializers_z9 (preprocess/rules/cleanup_unused_initializers.py)
  • removes unused initializers/value_info
• Improved preprocess report visibility so BN target/fold counts are easier to diagnose.

1. Runtime/logging and developer experience

• Filtered verbose Captures: lines during SavedModel export.
• Suppressed TensorFlow startup STDERR noise with:
  • ONNX2TF_SUPPRESS_TF_STARTUP_STDERR (default: enabled)
• Enhanced flatbuffer_direct OP error and tensor-correspondence reporting.

1. Docs/metadata updates

• Updated README OP summary.
• Updated package metadata/version files (__init__.py, pyproject.toml).

Validation

Validated mainly with real conversion runs (examples):

• text_detection_en_ppocrv3_2023may_int8.onnx
• human_segmentation_pphumanseg_2023mar_int8.onnx
• pose_estimation_mediapipe_2023mar_int8bq.onnx
• face_recognition_sface_2021dec_int8.onnx

Also confirmed:

• python -m compileall on key modified modules
• preprocess-only checks for bn_fold_wave0 and cleanup_unused_initializers_z9 statistics

What's Changed

• Enhance flatbuffer_direct stability: shape propagation, quantized fusion, BN/preprocess folding by @PINTO0309 in https://github.com/PINTO0309/onnx2tf/pull/877

Full Changelog: https://github.com/PINTO0309/onnx2tf/compare/2.0.14...2.0.15