BiRefNet Portrait TensorRT

Model Description

BiRefNet Portrait TensorRT is a high-performance background removal model optimized for NVIDIA GPUs using TensorRT. It delivers 5.3x speedup over standard PyTorch inference with a median latency of 123ms at 1024x1024 resolution (RTX 3060, FP16).

This model is a TensorRT-optimized version of BiRefNet trained specifically for portrait matting, ideal for real-time selfie and photo background removal applications.

• Model type: Image Segmentation / Portrait Matting
• License: See original BiRefNet repository for license details
• Parent Model: ZhengPeng7/BiRefNet
• Related Model: briaai/RMBG-2.0

Model Details

Model Architecture

Training Data

The original BiRefNet model was trained on:

Model Specifications

• File Size: ~615 MB
• Engine Version: TensorRT 10.x compatible
• CUDA Requirements: CUDA 12.0+
• GPU Memory: ~2GB at 1024x1024 FP16

Intended Uses & Limitations

Intended Uses

• Selfie background removal - Real-time processing of portrait photos
• Video conferencing - Virtual background for live video
• Photo editing - Batch background removal for portrait photography
• Portrait matting - High-quality alpha extraction for compositing

Limitations

• Input constraints: Optimized for 1024×1024 resolution; resizing required for other sizes
• Subject matter: Trained primarily on human portraits; performance may vary on non-human subjects
• Background complexity: Works best with distinct foreground/background separation
• Hardware: Requires NVIDIA GPU with TensorRT support
• Batch size: Currently optimized for single-image inference (batch=1)

How to Get Started with the Model

This TensorRT engine file (birefnet_portrait.trt) can be used in two ways:

Option 1: Using Transformers (Recommended for Python)

from transformers import pipeline

# Load the pipeline with TensorRT support
remover = pipeline("image-segmentation", model="israellaguan/birefnet-portrait-tensorrt")

# Process an image
result = remover("input.jpg")

Option 2: Using Official TensorRT APIs

For production deployment or C++ applications, use the official TensorRT runtime as documented in the NVIDIA TensorRT Quick Start Guide:

import tensorrt as trt
import pycuda.driver as cuda
import pycuda.autoinit

# Load engine
logger = trt.Logger(trt.Logger.WARNING)
with open("birefnet_portrait.trt", "rb") as f:
    runtime = trt.Runtime(logger)
    engine = runtime.deserialize_cuda_engine(f.read())

# Create execution context
context = engine.create_execution_context()

# Allocate buffers and run inference
# See NVIDIA TensorRT documentation for complete examples

Option 3: Using the Provided Python Package

This repository includes a complete Python package in the rmbg/ folder with CLI and API for running the TensorRT model. See rmbg/README.md for detailed usage:

# CLI usage
python -m rmbg.cli process input.jpg -o output/

# With options
python -m rmbg.cli process input.jpg -o output/ --verbose --warmup

The rmbg/ package provides:

• CLI tool (cli.py) - Command-line interface with progress bars
• Python API (tools/) - Pipeline and BackgroundRemover classes
• TensorRT backend (backends/tensorrt.py) - Native TensorRT inference

Requirements

pip install tensorrt pycuda Pillow numpy

• CUDA 12.0+
• TensorRT 10.x
• NVIDIA GPU with Compute Capability 7.0+

Performance Benchmarks

Tested on RTX 3060, CUDA 12.0, TensorRT 10.8, 1024×1024 input

Conversion Process

This model was converted from PyTorch to TensorRT using the ONNX intermediate format:

PyTorch → ONNX → TensorRT Engine

Step 1: Export to ONNX

import torch

# Load your BiRefNet model
checkpoint_path = "BiRefNet-portrait-epoch_150.pth"  # or any model from https://github.com/ZhengPeng7/BiRefNet/releases
device = torch.device("cuda")

# Create model and load weights
from models.birefnet import BiRefNet
from utils import check_state_dict

model = BiRefNet(bb_pretrained=False)
state_dict = torch.load(checkpoint_path, map_location='cpu', weights_only=True)
state_dict = check_state_dict(state_dict)
model.load_state_dict(state_dict)
model = model.eval().to(device)

# Export to ONNX
dummy_input = torch.randn(1, 3, 1024, 1024).to(device)
torch.onnx.export(
    model,
    dummy_input,
    "birefnet_portrait.onnx",
    export_params=True,
    opset_version=17,
    do_constant_folding=True,
    input_names=['input_image'],
    output_names=['output_mask'],
    dynamic_axes={
        'input_image': {0: 'batch_size', 2: 'height', 3: 'width'},
        'output_mask': {0: 'batch_size', 2: 'height', 3: 'width'}
    },
)

Step 2: Build TensorRT Engine

import tensorrt as trt

logger = trt.Logger(trt.Logger.INFO)
builder = trt.Builder(logger)
network = builder.create_network(
    1 << int(trt.NetworkDefinitionCreationFlag.EXPLICIT_BATCH)
)
parser = trt.OnnxParser(network, logger)

# Parse ONNX model
with open("birefnet_portrait.onnx", 'rb') as f:
    if not parser.parse(f.read()):
        for error in range(parser.num_errors):
            print(parser.get_error(error))
        raise RuntimeError("ONNX parsing failed")

# Configure builder
config = builder.create_builder_config()
config.set_memory_pool_limit(trt.MemoryPoolType.WORKSPACE, 4 * (1 << 30))  # 4GB workspace
config.set_flag(trt.BuilderFlag.FP16)  # Enable FP16 precision

# Build engine
serialized_engine = builder.build_serialized_network(network, config)
if serialized_engine is None:
    raise RuntimeError("Engine build failed")

# Save engine
with open("birefnet_portrait.trt", 'wb') as f:
    f.write(serialized_engine)

print(f"TensorRT engine saved: {len(serialized_engine) / (1024**2):.1f} MB")

Available Models

Other BiRefNet models can be converted using the same process. Download checkpoints from:

• Official releases: https://github.com/ZhengPeng7/BiRefNet/releases
• Portrait model (used here): BiRefNet-portrait-epoch_150.pth
• General purpose: BiRefNet-general-epoch_240.pth
• High-resolution matting: Various task-specific models available

Note on prior work: Previous BiRefNet TensorRT implementations (lbq779660843/BiRefNet-Tensorrt and yuanyang1991/birefnet_tensorrt) were published 2 years ago and provide only conversion directions without downloadable pre-built models. This repository provides a ready-to-use TensorRT engine.

Citation

If you use this model, please cite the original BiRefNet paper:

@article{biRefNet2024,
  title={BiRefNet: Bilateral Reference Network for High-Resolution Dichotomous Image Segmentation},
  author={Zheng, Peng and Gao, Dehong and Fan, Guolei and Li, Sheng and Sarkar, Berihun},
  journal={arXiv preprint},
  year={2024}
}