--- comments: true --- # Vehicle Attribute Recognition Module Tutorial ## I. Overview Vehicle attribute recognition is a crucial component in computer vision systems. Its primary task is to locate and label specific attributes of vehicles in images or videos, such as vehicle type, color, license plate number, etc. The performance of this module directly impacts the accuracy and efficiency of the entire computer vision system. The vehicle attribute recognition module typically outputs bounding boxes (Bounding Boxes) containing vehicle attribute information, which are then passed as input to other modules (e.g., vehicle tracking, vehicle re-identification) for subsequent processing. ## II. Supported Model List
ModelModel Download Link mA (%) GPU Inference Time (ms)
[Normal Mode / High-Performance Mode]
CPU Inference Time (ms)
[Normal Mode / High-Performance Mode]
Model Storage Size (MB) Description
PP-LCNet_x1_0_vehicle_attribute Inference Model/Training Model 91.7 2.53 / 0.67 2.73 / 1.10 6.7 PP-LCNet_x1_0_vehicle_attribute is a lightweight vehicle attribute recognition model based on PP-LCNet.
Test Environment Description:
Mode GPU Configuration CPU Configuration Acceleration Technology Combination
Normal Mode FP32 Precision / No TRT Acceleration FP32 Precision / 8 Threads PaddleInference
High-Performance Mode Optimal combination of pre-selected precision types and acceleration strategies FP32 Precision / 8 Threads Pre-selected optimal backend (Paddle/OpenVINO/TRT, etc.)
## III. Quick Integration > ❗ Before quick integration, please install the PaddleX wheel package. For detailed instructions, refer to [PaddleX Local Installation Guide](../../../installation/installation.en.md) After installing the wheel package, a few lines of code can complete the inference of the vehicle attribute recognition module. You can easily switch models under this module, and you can also integrate the model inference of the vehicle attribute recognition module into your project. Before running the following code, please download the [demo image](https://paddle-model-ecology.bj.bcebos.com/paddlex/imgs/demo_image/vehicle_attribute_007.jpg) to your local machine. ```python from paddlex import create_model model = create_model(model_name="PP-LCNet_x1_0_vehicle_attribute") output = model.predict("vehicle_attribute_007.jpg", batch_size=1) for res in output: res.print(json_format=False) res.save_to_img("./output/") res.save_to_json("./output/res.json") ``` After running, the obtained result is: ```bash {'res': {'input_path': 'vehicle_attribute_007.jpg', 'page_index': None, 'class_ids': array([ 0, 13]), 'scores': array([0.98929, 0.97349]), 'label_names': ['yellow(黄色)', 'hatchback(掀背车)']}} ``` The meanings of the parameters in the running result are as follows: - `input_path`: Indicates the path of the input multi-category image to be predicted. - `page_index`: If the input is a PDF file, it indicates which page of the PDF is currently being processed; otherwise, it is `None`. - `class_ids`: Indicates the predicted label IDs of the vehicle attribute images. - `scores`: Indicates the confidence scores of the predicted labels of the vehicle attribute images. - `label_names`: Indicates the names of the predicted labels of the vehicle attribute images. The visualization image is as follows: Vehicle Attribute Result Relevant methods, parameters, and explanations are as follows: * `create_model` instantiates the vehicle attribute recognition model (here, `PP-LCNet_x1_0_vehicle_attribute` is used as an example). The specific explanations are as follows:
Parameter Parameter Description Parameter Type Options Default Value
model_name The name of the model str None PP-LCNet_x1_0_vehicle_attribute
model_dir The storage path of the model str None None
device The device used for model inference str It supports specifying specific GPU card numbers, such as "gpu:0", other hardware card numbers, such as "npu:0", or CPU, such as "cpu". gpu:0
threshold The threshold for vehicle attribute recognition float/list/dict
  • float variable, any floating-point number between [0-1]: 0.5
  • list variable, a list composed of multiple floating-point numbers between [0-1]: [0.5,0.5,...]
  • dict variable, specifying different thresholds for different categories, where "default" is a required key: {"default":0.5,1:0.1,...}
  • 0.5
    use_hpip Whether to enable the high-performance inference plugin bool None False
    hpi_config High-performance inference configuration dict | None None None
    * The `model_name` must be specified. After specifying `model_name`, PaddleX's built-in model parameters are used by default. If `model_dir` is specified, the user-defined model is used. * The `threshold` parameter is used to set the threshold for multi-label classification, with a default value of 0.7. When set as a float, it means all categories use this threshold; when set as a list, different categories use different thresholds, and the list length must match the number of categories; when set as a dictionary, "default" is a required key, indicating the default threshold for all categories, while other categories use their respective thresholds. For example: {"default":0.5,1:0.1}. * The `predict()` method of the multi-label classification model is called for inference prediction. The parameters of the `predict()` method include `input`, `batch_size`, and `threshold`, with specific explanations as follows:
    Parameter Description Type Options Default Value
    input Data to be predicted, supporting multiple input types Python Var/str/list
    • Python variable, such as image data represented by numpy.ndarray
    • File path, such as the local path of an image file: /root/data/img.jpg
    • URL link, such as the network URL of an image file: Example
    • Local directory, the directory should contain data files to be predicted, such as the local path: /root/data/
    • List, elements of the list should be of the above types, such as [numpy.ndarray, numpy.ndarray], [\"/root/data/img1.jpg\", \"/root/data/img2.jpg\"], [\"/root/data1\", \"/root/data2\"]
    None
    batch_size Batch size int Any integer 1
    threshold Threshold for vehicle attribute recognition float/list/dict
  • float variable, any floating-point number between [0-1]: 0.5
  • list variable, a list of multiple floating-point numbers between [0-1]: [0.5,0.5,...]
  • dict variable, specifying different thresholds for different categories, where "default" is a required key: {"default":0.5,1:0.1,...}
  • 0.5
    * The prediction results are processed, with each sample's prediction result being a corresponding Result object, which supports operations such as printing, saving as an image, and saving as a json file:
    Method Description Parameter Type Description Default Value
    print() Print the result to the terminal format_json bool Whether to format the output content using JSON indentation True
    indent int Specify the indentation level to beautify the output JSON data and make it more readable, effective only when format_json is True 4
    ensure_ascii bool Control whether non-ASCII characters are escaped to Unicode. If set to True, all non-ASCII characters will be escaped; False retains the original characters, effective only when format_json is True False
    save_to_json() Save the result as a json file save_path str The file path for saving; if it is a directory, the saved file will be named consistently with the input file type None
    indent int Specify the indentation level to beautify the output JSON data and make it more readable, effective only when format_json is True 4
    ensure_ascii bool Control whether non-ASCII characters are escaped to Unicode. If set to True, all non-ASCII characters will be escaped; False retains the original characters, effective only when format_json is True False
    save_to_img() Save the result as an image file save_path str The file path for saving; if it is a directory, the saved file will be named consistently with the input file type None
    * In addition, it also supports obtaining visualized images with results and prediction results through attributes, as follows:
    Attribute Description
    json Get the prediction result in json format
    img Get the visualized image in dict format
    For more information on using PaddleX's single-model inference API, refer to [PaddleX Single Model Python Script Usage Instructions](../../instructions/model_python_API.en.md). Note: In the `output`, values indexed from 0-9 represent color attributes, corresponding to the following colors respectively: yellow, orange, green, gray, red, blue, white, golden, brown, black. Indices 10-18 represent vehicle type attributes, corresponding to the following vehicle types: sedan, suv, van, hatchback, mpv, pickup, bus, truck, estate. ## IV. Custom Development If you seek higher accuracy from existing models, you can leverage PaddleX's custom development capabilities to develop better vehicle attribute recognition models. Before using PaddleX to develop vehicle attribute recognition models, ensure you have installed the classification-related model training plugin for PaddleX. The installation process can be found in the [PaddleX Local Installation Guide](../../../installation/installation.en.md). ### 4.1 Data Preparation Before model training, you need to prepare the corresponding dataset for the task module. PaddleX provides a data validation function for each module, and only data that passes validation can be used for model training. Additionally, PaddleX provides demo datasets for each module, which you can use to complete subsequent development. If you wish to use private datasets for model training, refer to [PaddleX Multi-Label Classification Task Module Data Annotation Tutorial](../../../data_annotations/cv_modules/ml_classification.en.md). #### 4.1.1 Demo Data Download You can use the following commands to download the demo dataset to a specified folder: ```bash wget https://paddle-model-ecology.bj.bcebos.com/paddlex/data/vehicle_attribute_examples.tar -P ./dataset tar -xf ./dataset/vehicle_attribute_examples.tar -C ./dataset/ ``` #### 4.1.2 Data Validation A single command can complete data validation: ```bash python main.py -c paddlex/configs/modules/vehicle_attribute_recognition/PP-LCNet_x1_0_vehicle_attribute.yaml \ -o Global.mode=check_dataset \ -o Global.dataset_dir=./dataset/vehicle_attribute_examples ``` After executing the above command, PaddleX will validate the dataset and summarize its basic information. If the command runs successfully, it will print `Check dataset passed !` in the log. The validation results file is saved in `./output/check_dataset_result.json`, and related outputs are saved in the `./output/check_dataset` directory in the current directory, including visual examples of sample images and sample distribution histograms.
    👉 Details of Validation Results (Click to Expand)

    The specific content of the validation result file is:

    {
      "done_flag": true,
      "check_pass": true,
      "attributes": {
        "label_file": "../../dataset/vehicle_attribute_examples/label.txt",
        "num_classes": 19,
        "train_samples": 1200,
        "train_sample_paths": [
          "check_dataset/demo_img/0018_c017_00033140_0.jpg",
          "check_dataset/demo_img/0010_c019_00034275_0.jpg",
          "check_dataset/demo_img/0015_c019_00068660_0.jpg",
          "check_dataset/demo_img/0016_c017_00049590_1.jpg",
          "check_dataset/demo_img/0018_c016_00052280_0.jpg",
          "check_dataset/demo_img/0023_c001_00006995_0.jpg",
          "check_dataset/demo_img/0022_c004_00065910_0.jpg",
          "check_dataset/demo_img/0007_c019_00048655_1.jpg",
          "check_dataset/demo_img/0022_c007_00072970_0.jpg",
          "check_dataset/demo_img/0022_c008_00065785_0.jpg"
        ],
        "val_samples": 300,
        "val_sample_paths": [
          "check_dataset/demo_img/0025_c003_00054095_0.jpg",
          "check_dataset/demo_img/0023_c013_00006350_1.jpg",
          "check_dataset/demo_img/0024_c003_00046320_0.jpg",
          "check_dataset/demo_img/0025_c005_00054795_2.jpg",
          "check_dataset/demo_img/0024_c012_00041770_0.jpg",
          "check_dataset/demo_img/0024_c007_00060845_1.jpg",
          "check_dataset/demo_img/0023_c017_00013150_0.jpg",
          "check_dataset/demo_img/0024_c014_00040410_0.jpg",
          "check_dataset/demo_img/0025_c002_00050685_1.jpg",
          "check_dataset/demo_img/0025_c005_00032645_0.jpg"
        ]
      },
      "analysis": {
        "histogram": "check_dataset/histogram.png"
      },
      "dataset_path": "vehicle_attribute_examples",
      "show_type": "image",
      "dataset_type": "MLClsDataset"
    }
    

    In the above validation results, check_pass being True indicates that the dataset format meets the requirements. Explanations for other indicators are as follows:

    Additionally, the dataset verification also analyzes the distribution of the length and width of all images in the dataset and plots a histogram (histogram.png):

    #### 4.1.3 Dataset Format Conversion / Dataset Splitting (Optional) After completing dataset verification, you can convert the dataset format or re-split the training/validation ratio by modifying the configuration file or appending hyperparameters.
    👉 Details on Format Conversion / Dataset Splitting (Click to Expand)

    (1) Dataset Format Conversion

    Vehicle attribute recognition does not support dataset format conversion.

    (2) Dataset Splitting

    The dataset splitting parameters can be set by modifying the fields under CheckDataset in the configuration file. An example of part of the configuration file is shown below:

    For example, if you want to re-split the dataset with 90% training set and 10% validation set, modify the configuration file as follows:

    ......
    CheckDataset:
      ......
      split:
        enable: True
        train_percent: 90
        val_percent: 10
      ......
    

    Then execute the command:

    python main.py -c paddlex/configs/modules/vehicle_attribute_recognition/PP-LCNet_x1_0_vehicle_attribute.yaml \
        -o Global.mode=check_dataset \
        -o Global.dataset_dir=./dataset/vehicle_attribute_examples
    

    After dataset splitting, the original annotation files will be renamed to xxx.bak in the original path.

    The above parameters can also be set by appending command-line arguments:

    python main.py -c paddlex/configs/modules/vehicle_attribute_recognition/PP-LCNet_x1_0_vehicle_attribute.yaml  \
        -o Global.mode=check_dataset \
        -o Global.dataset_dir=./dataset/vehicle_attribute_examples \
        -o CheckDataset.split.enable=True \
        -o CheckDataset.split.train_percent=90 \
        -o CheckDataset.split.val_percent=10
    
    ### 4.2 Model Training Training a model can be done with a single command, taking the training of the PP-LCNet vehicle attribute recognition model (`PP-LCNet_x1_0_vehicle_attribute`) as an example: ```bash python main.py -c paddlex/configs/modules/vehicle_attribute_recognition/PP-LCNet_x1_0_vehicle_attribute.yaml \ -o Global.mode=train \ -o Global.dataset_dir=./dataset/vehicle_attribute_examples ``` The steps required are: * Specify the path to the model's `.yaml` configuration file (here it's `PP-LCNet_x1_0_vehicle_attribute.yaml`,When training other models, you need to specify the corresponding configuration files. The relationship between the model and configuration files can be found in the [PaddleX Model List (CPU/GPU)](../../../support_list/models_list.en.md)) * Set the mode to model training: `-o Global.mode=train` * Specify the path to the training dataset: `-o Global.dataset_dir` * Other related parameters can be set by modifying the `Global` and `Train` fields in the `.yaml` configuration file, or adjusted by appending parameters in the command line. For example, to specify training on the first two GPUs: `-o Global.device=gpu:0,1`; to set the number of training epochs to 10: `-o Train.epochs_iters=10`. For more modifiable parameters and their detailed explanations, refer to the [PaddleX Common Configuration Parameters](../../instructions/config_parameters_common.en.md). * New Feature: Paddle 3.0 support CINN (Compiler Infrastructure for Neural Networks) to accelerate training speed when using GPU device. Please specify `-o Train.dy2st=True` to enable it.
    👉 More Details (Click to Expand)
    ### 4.3 Model Evaluation After completing model training, you can evaluate the specified model weights file on the validation set to verify the model's accuracy. Using PaddleX for model evaluation can be done with a single command: ```bash python main.py -c paddlex/configs/modules/vehicle_attribute_recognition/PP-LCNet_x1_0_vehicle_attribute.yaml \ -o Global.mode=evaluate \ -o Global.dataset_dir=./dataset/vehicle_attribute_examples ``` Similar to model training, the following steps are required: * Specify the path to the model's `.yaml` configuration file (here it is `PP-LCNet_x1_0_vehicle_attribute.yaml`) * Specify the mode as model evaluation: `-o Global.mode=evaluate` * Specify the path to the validation dataset: `-o Global.dataset_dir` Other related parameters can be set by modifying the `Global` and `Evaluate` fields in the `.yaml` configuration file. For details, refer to [PaddleX Common Model Configuration File Parameter Description](../../instructions/config_parameters_common.en.md).
    👉 More Details (Click to Expand)

    When evaluating the model, you need to specify the model weights file path. Each configuration file has a default weight save path built-in. If you need to change it, simply set it by appending a command line parameter, such as -o Evaluate.weight_path=./output/best_model/best_model.pdparams.

    After completing the model evaluation, an evaluate_result.json file will be produced, which records the evaluation results, specifically, whether the evaluation task was completed successfully and the model's evaluation metrics, including MultiLabelMAP;

    ### 4.4 Model Inference and Integration After completing model training and evaluation, you can use the trained model weights for inference prediction or Python integration. #### 4.4.1 Model Inference To perform inference prediction through the command line, simply use the following command. Before running the following code, please download the [demo image](https://paddle-model-ecology.bj.bcebos.com/paddlex/imgs/demo_image/vehicle_attribute_007.jpg) to your local machine. ```bash python main.py -c paddlex/configs/modules/vehicle_attribute_recognition/PP-LCNet_x1_0_vehicle_attribute.yaml \ -o Global.mode=predict \ -o Predict.model_dir="./output/best_model/inference" \ -o Predict.input="vehicle_attribute_007.jpg" ``` Similar to model training and evaluation, the following steps are required: * Specify the `.yaml` configuration file path for the model (here it is `PP-LCNet_x1_0_vehicle_attribute.yaml`,When training other models, you need to specify the corresponding configuration files. The relationship between the model and configuration files can be found in the [PaddleX Model List (CPU/GPU)](../../../support_list/models_list.en.md)) * Set the mode to model inference prediction: `-o Global.mode=predict` * Specify the model weights path: `-o Predict.model_dir="./output/best_model/inference"` * Specify the input data path: `-o Predict.input="..."` Other related parameters can be set by modifying the `Global` and `Predict` fields in the `.yaml` configuration file. For details, please refer to [PaddleX Common Model Configuration File Parameter Description](../../instructions/config_parameters_common.en.md). #### 4.4.2 Model Integration The model can be directly integrated into the PaddleX pipeline or directly into your own project. 1.Pipeline Integration The vehicle attribute recognition module can be integrated into the [Vehicle Attribute Recognition Pipeline](../../../pipeline_usage/tutorials/cv_pipelines/vehicle_attribute_recognition.en.md) of PaddleX. Simply replace the model path to update the vehicle attribute recognition module of the relevant pipeline. In pipeline integration, you can use high-performance inference and serving deployment to deploy your model. 2.Module Integration The weights you produce can be directly integrated into the vehicle attribute recognition module. Refer to the Python example code in Quick Integration and simply replace the model with the path to your trained model. You can also use the PaddleX high-performance inference plugin to optimize the inference process of your model and further improve efficiency. For detailed procedures, please refer to the [PaddleX High-Performance Inference Guide](../../../pipeline_deploy/high_performance_inference.en.md).