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OCDNet

OfficialFree

Efficient scene text detection in images.

by nvidia2.8k stars on nvidia/skills
Updated Aug 7, 2026
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Free · Opens the source repo

What OCDNet does

OCDNet is a specialized tool designed for scene text detection, particularly effective at identifying arbitrary-oriented text regions within natural images. This skill utilizes a differentiable binarization approach, which enhances its capability to accurately detect text in various orientations and backgrounds. It is particularly useful for developers and researchers working in computer vision, machine learning, and artificial intelligence fields, where text detection is critical for applications such as document analysis, augmented reality, and autonomous systems.

The skill provides a comprehensive set of functionalities including training, evaluating, exporting, pruning, quantizing, retraining, and running inference on TAO OCDNet models. Users can initiate these processes through simple command-line interfaces, making it accessible for both experienced developers and those new to machine learning. To get started, users need to set the model.pretrained_model_path to utilize pretrained weights, ensuring a solid foundation for their text detection tasks.

For deployment, the skill includes various spec templates that facilitate the integration of the OCDNet model into TensorRT workflows. This allows users to efficiently generate TensorRT engines, evaluate model performance, and run inference, all of which are crucial for optimizing model deployment in production environments. The detailed references and schemas provided within the skill package support users in customizing their workflows according to specific project requirements.

Overall, OCDNet is an essential skill for anyone involved in text detection tasks, offering robust tools and a streamlined workflow to enhance productivity and model accuracy. Its focus on arbitrary-oriented text detection sets it apart in the landscape of computer vision tools, making it a valuable addition to any developer's toolkit.

When to use it

Use this skill when you need to train or deploy models for detecting text in images, especially in scenarios where text orientation varies.

When not to use it

This skill may not be suitable for basic text detection tasks where text is consistently oriented or for users seeking a more general-purpose image processing tool.

What you can build with it

Training a New Model

You can train a new OCDNet model using your dataset by configuring the training parameters and providing the required dataset paths.

Running Inference

Once trained, use the skill to run inference on new images to detect text, utilizing the optimized TensorRT engine.

Evaluating Model Performance

Evaluate the performance of your trained model using the evaluation features provided in the skill to ensure accuracy and reliability.

How to install OCDNet

View source

1. Install with the skills CLI

npx skills add nvidia/skills/tao-train-ocdnet --agent claude-code

2. Or install it manually

Download the skill folder and drop it into ~/.claude/skills/ for all projects, or .claude/skills/ to scope it to one repo. Restart Claude Code so it picks up the new skill.

Anthropic's agentic coding CLI, and the reference implementation of Agent Skills. Drop a skill folder into ~/.claude/skills and Claude Code loads it automatically whenever a task matches the skill's description. Claude Code docs

Inside SKILL.md

Written by nvidia

OCDNet

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 still requires schemas/train.schema.json and references/spec_template_train.yaml to exist and parse. Use the packaged train 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
  • Monitoring metric: hmean

Per-Action Dataset Requirements

ActionSpec KeySourceRuntime valueList?
evaluatedataset.validate_dataset.data_patheval_datasetextracted validation split folder with img/ and gt/Yes
inferenceinference.input_folderinference_dataset or eval_datasetextracted image folderNo
prunedataset.validate_dataset.data_patheval_datasetextracted validation split folder with img/ and gt/Yes
quantizedataset.train_dataset.data_pathtrain_datasetsextracted train split folder with img/ and gt/Yes
quantizedataset.validate_dataset.data_patheval_datasetextracted validation split folder with img/ and gt/Yes
quantizedataset.quant_calibration_dataset.images_dirtrain_datasets or calibration_datasetextracted calibration image folderNo
traindataset.train_dataset.data_pathtrain_datasetsextracted train split folder with img/ and gt/Yes
traindataset.validate_dataset.data_patheval_datasetextracted validation split folder with img/ and gt/Yes
retraindataset.train_dataset.data_pathtrain_datasetsextracted train split folder with img/ and gt/Yes
retraindataset.validate_dataset.data_patheval_datasetextracted 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 KeyDescriptionDefault
train.num_gpusNumber of GPUs1
train.gpu_idsGPU device indices[0]
train.distributed_strategyddp, fsdp, or deepspeed_stage_3_offloadddp
  • 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:

ActionSpec FieldInference FunctionMeaning
evaluateevaluate.checkpointparent_modelmodel file inferred from the parent job results folder
evaluateresults_diroutput_dircurrent job results directory
exportexport.checkpointparent_modelmodel file inferred from the parent job results folder
exportexport.onnx_filecreate_onnx_fileoutput ONNX path
exportresults_diroutput_dircurrent job results directory
inferenceinference.checkpointparent_modelmodel file inferred from the parent job results folder
inferenceresults_diroutput_dircurrent job results directory
pruneprune.checkpointparent_modelmodel file inferred from the parent job results folder
pruneresults_diroutput_dircurrent job results directory
quantizequantize.model_pathparent_modelmodel file inferred from the parent job results folder
quantizeresults_diroutput_dircurrent job results directory
retrain from prunemodel.pruned_graph_pathparent_modelexact pruned model file inferred from the parent prune results folder
retrain from pruneresults_diroutput_dircurrent job results directory
trainmodel.pretrained_model_pathptm_if_no_resume_modelPTM when no resume checkpoint exists
trainresults_diroutput_dircurrent job results directory
traintrain.resume_training_checkpoint_pathresume_modelmodel file inferred from the current job results folder

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

Frequently asked questions about OCDNet

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