tao-train-ocdnet

name	tao-train-ocdnet
description	OCDNet for scene text detection. Detects arbitrary-oriented text regions in natural images using a differentiable binarization approach. Use when training, evaluating, exporting, pruning, quantizing, retraining, or running inference for a TAO OCDNet model. Trigger phrases include "train OCDNet", "scene text detection", "arbitrary-oriented text boxes", "differentiable binarization detector".
license	Apache-2.0
compatibility	Requires docker + nvidia-container-toolkit.
metadata	{"version":"0.1.0","author":"NVIDIA Corporation"}
allowed-tools	Read Bash
tags	["text","detection"]

OCDNet

Standalone install? If this session was not initialized by the TAO skill bank plugin, run the tao-setup skill first (host preflight, credentials, cross-skill discovery).

OCDNet for scene text detection. Detects arbitrary-oriented text regions in natural images using a differentiable binarization approach.

Set model.pretrained_model_path for pretrained weights.

For TAO Deploy TensorRT actions (gen_trt_engine, TensorRT evaluate, and TensorRT inference), read references/tao-deploy-ocdnet.md first. Deploy spec templates live in this skill's references/ folder with the spec_template_deploy_*.yaml prefix.

The PyT OCDNet CLI supports train, evaluate, export, inference, prune, quantize, and default_specs. It does not expose PyT-side retrain or gen_trt_engine subcommands. The model skill exposes retrain by running ocdnet train with model.load_pruned_graph: true and model.pruned_graph_path. Resume from an epoch checkpoint uses ocdnet train plus train.resume_training_checkpoint_path. TensorRT engine generation is owned by the deploy workflow.

Dataclass Schemas

Generated TAO Core schemas are packaged in schemas/<action>.schema.json, with schemas/manifest.json listing available actions. Each generated schema also emits references/spec_template_<action>.yaml from the schema top-level default field. AutoML enablement is declared at the model layer in references/skill_info.yaml via automl_enabled. Runnable AutoML for an action requires schemas/<action>.schema.json and references/spec_template_<action>.yaml to exist and parse. Use the packaged selected-action schema for automl_default_parameters, automl_disabled_parameters, defaults, min/max bounds, enums, option weights, math conditions, dependencies, and popular parameters. Do not expect ~/tao-core at runtime; maintainers regenerate schemas/templates before packaging the skill bank.

Train Action Policy

This model is AutoML-enabled at the model layer. Before handling any train-stage request, read references/skill_info.yaml and resolve the run override from either an explicit automl_policy value or the user's workflow request. Use automl_policy: on by default and only expose on / off in new launch prompts. Treat phrases like "turn off AutoML", "disable AutoML", "no HPO", or "plain training" as automl_policy: off for this run only. When automl_policy: on, automl_enabled: true, and both schemas/train.schema.json and references/spec_template_train.yaml are packaged, route the train action through tao-skill-bank:tao-run-automl by default with this model's skill_dir. Preserve workflow/application overrides for datasets, specs, output directories, GPU/platform settings, parent checkpoints, and automl_policy. Use direct model training only when automl_policy: off or the packaged train schema/template is missing; in the missing-schema case, report that AutoML is enabled but not runnable for this model until schemas are generated.

For AutoML train, use train_loss_epoch or train_loss as the optimization metric with direction=minimize. The Lightning progress log emits train_loss_epoch, and TAO status.json records the same final value under train_loss. For one-epoch local AutoML smoke runs, set train.lr_scheduler.args.warmup_epoch: 0; leaving warmup equal to the epoch budget causes the trainer to fail before a recommendation can report a metric. Non-train actions such as evaluate, inference, export, and deploy flows stay in this model skill. The per-run automl_policy override does not change model metadata.

Training Requirements

• Dataset type: ocdnet
• Formats: default
• AutoML training metric: train_loss (the status logger's final train_loss_epoch value), with direction=minimize
• AutoML metric contract: Use train_loss emitted during training and minimize it. Treat train_loss_epoch as a log fallback alias only; use standalone hmean solely to validate the selected checkpoint.
• Standalone evaluation metric: hmean, with direction=maximize

Per-Action Dataset Requirements

Action	Spec Key	Source	Runtime value	List?
evaluate	dataset.validate_dataset.data_path	eval_dataset	extracted validation split folder with img/ and gt/	Yes
inference	inference.input_folder	inference_dataset or eval_dataset	extracted image folder	No
prune	dataset.validate_dataset.data_path	eval_dataset	extracted validation split folder with img/ and gt/	Yes
quantize	dataset.train_dataset.data_path	train_datasets	extracted train split folder with img/ and gt/	Yes
quantize	dataset.validate_dataset.data_path	eval_dataset	extracted validation split folder with img/ and gt/	Yes
quantize	dataset.quant_calibration_dataset.images_dir	train_datasets or calibration_dataset	extracted calibration image folder	No
train	dataset.train_dataset.data_path	train_datasets	extracted train split folder with img/ and gt/	Yes
train	dataset.validate_dataset.data_path	eval_dataset	extracted validation split folder with img/ and gt/	Yes
retrain	dataset.train_dataset.data_path	train_datasets	extracted train split folder with img/ and gt/	Yes
retrain	dataset.validate_dataset.data_path	eval_dataset	extracted validation split folder with img/ and gt/	Yes

Typical Spec Overrides

Data source overrides are mandatory for every action — the agent MUST construct data source paths from the Per-Action Dataset Requirements table above and include them in spec_overrides. OCDNet does not unpack dataset archives at runtime. If the source is train.tar.gz, test.tar.gz, or img.tar.gz, extract it first and pass the split folder or image folder into the spec. The split folder must contain img/ and gt/; alternatively, pass a UTF-8 datalist text file whose lines map image paths to label paths.

TRAIN_ROOT = "/path/to/extracted/train"
EVAL_ROOT = "/path/to/extracted/test"
INFER_IMG_DIR = "/path/to/extracted/test/img"
CALIB_IMG_DIR = "/path/to/extracted/train/img"

train (mandatory data sources):

{
    "train.num_epochs": 30,
    "train.checkpoint_interval": 10,
    "train.validation_interval": 10,
    "train.num_gpus": 1,
    "dataset.train_dataset.loader.batch_size": 16,
    "dataset.train_dataset.data_path": [TRAIN_ROOT],
    "dataset.validate_dataset.data_path": [EVAL_ROOT],
}

evaluate (mandatory data sources):

{
    "evaluate.checkpoint": "<selected train/AutoML checkpoint>",
    "dataset.validate_dataset.data_path": [EVAL_ROOT],
}

inference (mandatory data sources):

{
    "inference.checkpoint": "<selected train/AutoML checkpoint>",
    "inference.input_folder": INFER_IMG_DIR,
}

prune (mandatory data sources):

{
    "prune.checkpoint": "<selected train/AutoML checkpoint>",
    "dataset.validate_dataset.data_path": [EVAL_ROOT],
}

quantize (mandatory data sources):

{
    "quantize.model_path": "<selected train checkpoint or exported ONNX>",
    "dataset.train_dataset.data_path": [TRAIN_ROOT],
    "dataset.validate_dataset.data_path": [EVAL_ROOT],
    "dataset.quant_calibration_dataset.images_dir": CALIB_IMG_DIR,
}

resume training (mandatory data sources):

{
    "train.resume_training_checkpoint_path": "<exact model_epoch checkpoint>",
    "dataset.train_dataset.data_path": [TRAIN_ROOT],
    "dataset.validate_dataset.data_path": [EVAL_ROOT],
}

retrain from prune output (mandatory data sources):

{
    "model.load_pruned_graph": True,
    "model.pruned_graph_path": "<selected prune output>",
    "dataset.train_dataset.data_path": [TRAIN_ROOT],
    "dataset.validate_dataset.data_path": [EVAL_ROOT],
}

default_specs:

{
    "results_dir": "<writable output directory>",
}

Eval Dataset

Optional. Test dataset provided as separate tarball.

Important Parameters

• model.backbone: Default deformable_resnet18. Deformable convolutions improve text region detection for irregular text.
• train.optimizer.args.lr: Learning rate. Default 0.001 (Adam).
• postprocess.thresh: Binarization threshold for text region extraction.
• postprocess.box_thresh: Box confidence threshold for filtering detections.

Multi-GPU / Multi-Node

Launch method: Lightning-managed (single python process, Lightning spawns workers).

Spec Key	Description	Default
train.num_gpus	Number of GPUs	1
train.gpu_ids	GPU device indices	[0]
train.distributed_strategy	ddp, fsdp, or deepspeed_stage_3_offload	ddp

• ddp with activation checkpointing: find_unused_parameters=False
• ddp without: find_unused_parameters=True
• fsdp forces FP16
• deepspeed_stage_3_offload is uniquely supported for OCDNet (forces FP16)
• FAN backbones auto-enable sync_batchnorm

Hardware

Minimum 1 GPU(s), recommended 1 GPU(s). 8GB+ VRAM per GPU. OCDNet is lightweight. Single GPU is sufficient for most datasets.

Error Patterns

Low detection rate: Tune postprocess.thresh and box_thresh. Default thresholds may be too aggressive for some datasets.

One-epoch smoke train with default scheduler: train.num_epochs must not equal train.lr_scheduler.args.warmup_epoch. For one-epoch validation, set warmup_epoch: 0; for normal starter runs, keep num_epochs > warmup_epoch.

Archive passed as dataset path: dataset.*.data_path is not an archive path for OCDNet. Passing train.tar.gz or test.tar.gz directly causes the dataloader to open the gzip as a UTF-8 datalist. Extract the archive and pass the split folder containing img/ and gt/, or pass a real UTF-8 datalist file.

Quantize checkpoint type: Do not pass model_best.pth to the PyTorch quantize path. Some older PyT runtimes wrote model_best.pth without full Lightning checkpoint metadata. The default torchao quantize path should use the intended full model_epoch_<epoch>_step_<step>.pth checkpoint and write quantized_model_torchao.pth.

Default specs output directory: ocdnet default_specs requires a writable results_dir override, for example results_dir=/workspace/run/results/default_specs.

Checkpoint Handoff

OCDNet train writes model_best.pth plus full Lightning epoch checkpoints such as model_epoch_001_step_00046.pth; it may also write ocd_model_latest.pth as a latest symlink. Use model_best.pth for evaluate.checkpoint, inference.checkpoint, export.checkpoint, and prune.checkpoint when the user asks for the best checkpoint. Use a specific model_epoch_<epoch>_step_<step>.pth for train.resume_training_checkpoint_path and for any action that explicitly needs a full Lightning checkpoint. Prune writes artifacts such as pruned_<ch_sparsity>.pth; use the exact pruned .pth artifact for model.pruned_graph_path when retraining from a pruned graph. Use a latest checkpoint only when the user explicitly asks for latest.

If quantize is retried with a PyTorch backend, resolve the full model_epoch_<epoch>_step_<step>.pth that corresponds to the intended best epoch or requested epoch; do not pass model_best.pth to the PyTorch quantize path. If quantize is retried with modelopt.onnx, pass the exported ONNX as quantize.model_path and verify that the runtime image actually contains modelopt.onnx.quantization.

Spec Param / Parent Model Inference

Model-specific inference mappings belong in this MD file, not in config.json. Generated runners should read this section and apply the mappings with SDK helpers before create_job(). This mirrors the old microservices infer_params.py flow.

Model handoff mappings:

Action	Spec Field	Inference Function	Meaning
evaluate	evaluate.checkpoint	parent_model	model file inferred from the parent job results folder
evaluate	results_dir	output_dir	current job results directory
export	export.checkpoint	parent_model	model file inferred from the parent job results folder
export	export.onnx_file	create_onnx_file	output ONNX path
export	results_dir	output_dir	current job results directory
inference	inference.checkpoint	parent_model	model file inferred from the parent job results folder
inference	results_dir	output_dir	current job results directory
prune	prune.checkpoint	parent_model	model file inferred from the parent job results folder
prune	results_dir	output_dir	current job results directory
quantize	quantize.model_path	parent_model	model file inferred from the parent job results folder
quantize	results_dir	output_dir	current job results directory
retrain from prune	model.pruned_graph_path	parent_model	exact pruned model file inferred from the parent prune results folder
retrain from prune	results_dir	output_dir	current job results directory

For parent_model or parent_model_folder, pass the upstream train/export/AutoML child job id as parent_job_id. The SDK lists the parent result folder, filters checkpoint artifacts, and returns the selected model file or folder. Do not add these mappings back to config.json and do not patch generated runner scripts to guess checkpoint paths.

Deployment

• tao-deploy-ocdnet