PaddleOCR/docs/version3.x/pipeline_usage/seal_recognition.en.md
Sunflower7788 01eb770118
add layout and seal docs (#15176)
* fix layout docs

* fix layout docs

* fix layout docs
2025-05-19 22:54:51 +08:00

94 KiB
Raw Blame History

comments
comments
true

Seal Text Recognition Pipeline Tutorial

1. Introduction to Seal Text Recognition Pipeline

Seal text recognition is a technology that automatically extracts and recognizes the content of seals from documents or images. The recognition of seal text is part of document processing and has many applications in various scenarios, such as contract comparison, warehouse entry and exit review, and invoice reimbursement review.

The seal text recognition pipeline is used to recognize the text content of seals, extracting the text information from seal images and outputting it in text form. This pipeline integrates the industry-renowned end-to-end OCR system PP-OCRv4, supporting the detection and recognition of curved seal text. Additionally, this pipeline integrates an optional layout region localization module, which can accurately locate the layout position of the seal within the entire document. It also includes optional document image orientation correction and distortion correction functions. Based on this pipeline, millisecond-level accurate text content prediction can be achieved on a CPU. This pipeline also provides flexible service deployment methods, supporting the use of multiple programming languages on various hardware. Moreover, it offers custom development capabilities, allowing you to train and fine-tune on your own dataset based on this pipeline, and the trained model can be seamlessly integrated.

The seal text recognition pipeline includes a seal text detection module and a text recognition module, as well as optional layout detection module, document image orientation classification module, and text image correction module.

If you prioritize model accuracy, choose a model with higher accuracy. If you prioritize inference speed, choose a model with faster inference speed. If you prioritize model storage size, choose a model with smaller storage size.

Layout Region Detection Module (Optional):

  • The layout detection model includes 20 common categories: document title, paragraph title, text, page number, abstract, table, references, footnotes, header, footer, algorithm, formula, formula number, image, table, seal, figure_table title, chart, and sidebar text and lists of references
ModelModel Download Link mAP(0.5) (%) GPU Inference Time (ms)
[Normal Mode / High-Performance Mode]
CPU Inference Time (ms)
[Normal Mode / High-Performance Mode]
Model Storage Size (M) Introduction
PP-DocLayout_plus-LInference Model/Training Model 83.2 34.6244 / 10.3945 510.57 / - 126.01 M A higher-precision layout area localization model trained on a self-built dataset containing Chinese and English papers, PPT, multi-layout magazines, contracts, books, exams, ancient books and research reports using RT-DETR-L
  • Layout detection model, including 23 common categories: document title, paragraph title, text, page number, abstract, table of contents, references, footnotes, header, footer, algorithm, formula, formula number, image, chart title, table, table title, seal, chart title, chart, header image, footer image, sidebar text
ModelModel Download Link mAP(0.5) (%) GPU Inference Time (ms)
[Normal Mode / High-Performance Mode]
CPU Inference Time (ms)
[Normal Mode / High-Performance Mode]
Model Storage Size (M) Introduction
PP-DocLayout-LInference Model/Training Model 90.4 34.6244 / 10.3945 510.57 / - 123.76 M A high-precision layout area localization model trained on a self-built dataset containing Chinese and English papers, magazines, contracts, books, exams, and research reports using RT-DETR-L.
PP-DocLayout-MInference Model/Training Model 75.2 13.3259 / 4.8685 44.0680 / 44.0680 22.578 A layout area localization model with balanced precision and efficiency, trained on a self-built dataset containing Chinese and English papers, magazines, contracts, books, exams, and research reports using PicoDet-L.
PP-DocLayout-SInference Model/Training Model 70.9 8.3008 / 2.3794 10.0623 / 9.9296 4.834 A high-efficiency layout area localization model trained on a self-built dataset containing Chinese and English papers, magazines, contracts, books, exams, and research reports using PicoDet-S.

The above list includes the 4 core models that are key supported by the text recognition module. The module actually supports a total of 13 full models. It includes multiple predefined models of different categories, among which there are 10 models specifically for the seal category. Apart from the three core models mentioned above, the remaining models are listed as follows:

👉 Details of Model List
  • 3-Class Layout Detection Model, including Table, Image, and Stamp
ModelModel Download Link mAP(0.5) (%) GPU Inference Time (ms)
[Normal Mode / High-Performance Mode]
CPU Inference Time (ms)
[Normal Mode / High-Performance Mode]
Model Storage Size (M) Introduction
PicoDet-S_layout_3clsInference Model/Training Model 88.2 8.99 / 2.22 16.11 / 8.73 4.8 A high-efficiency layout area localization model trained on a self-built dataset of Chinese and English papers, magazines, and research reports using PicoDet-S.
PicoDet-L_layout_3clsInference Model/Training Model 89.0 13.05 / 4.50 41.30 / 41.30 22.6 A balanced efficiency and precision layout area localization model trained on a self-built dataset of Chinese and English papers, magazines, and research reports using PicoDet-L.
RT-DETR-H_layout_3clsInference Model/Training Model 95.8 114.93 / 27.71 947.56 / 947.56 470.1 A high-precision layout area localization model trained on a self-built dataset of Chinese and English papers, magazines, and research reports using RT-DETR-H.
  • 17-Class Area Detection Model, including 17 common layout categories: Paragraph Title, Image, Text, Number, Abstract, Content, Figure Caption, Formula, Table, Table Caption, References, Document Title, Footnote, Header, Algorithm, Footer, and Stamp
ModelModel Download Link mAP(0.5) (%) GPU Inference Time (ms)
[Normal Mode / High-Performance Mode]
CPU Inference Time (ms)
[Normal Mode / High-Performance Mode]
Model Storage Size (M) Introduction
PicoDet-S_layout_17clsInference Model/Training Model 87.4 9.11 / 2.12 15.42 / 9.12 4.8 A high-efficiency layout area localization model trained on a self-built dataset of Chinese and English papers, magazines, and research reports using PicoDet-S.
PicoDet-L_layout_17clsInference Model/Training Model 89.0 13.50 / 4.69 43.32 / 43.32 22.6 A balanced efficiency and precision layout area localization model trained on a self-built dataset of Chinese and English papers, magazines, and research reports using PicoDet-L.
RT-DETR-H_layout_17clsInference Model/Training Model 98.3 115.29 / 104.09 995.27 / 995.27 470.2 A high-precision layout area localization model trained on a self-built dataset of Chinese and English papers, magazines, and research reports using RT-DETR-H.

Document Image Orientation Classification Module (Optional):

ModelModel Download Link Top-1 Acc (%) GPU Inference Time (ms)
[Normal Mode / High-Performance Mode]
CPU Inference Time (ms)
[Normal Mode / High-Performance Mode]
Model Storage Size (M) Description
PP-LCNet_x1_0_doc_oriInference Model/Training Model 99.06 2.31 / 0.43 3.37 / 1.27 7 A document image classification model based on PP-LCNet_x1_0, containing four categories: 0 degrees, 90 degrees, 180 degrees, and 270 degrees

Text Image Correction Module (Optional):

ModelModel Download Link CER Model Storage Size (M) Description
UVDocInference Model/Training Model 0.179 30.3 M High-precision text image correction model

Text Detection Module:

ModelModel Download Link Detection Hmean (%) GPU Inference Time (ms)
[Normal Mode / High-Performance Mode]
CPU Inference Time (ms)
[Normal Mode / High-Performance Mode]
Model Storage Size (M) Description
PP-OCRv4_server_seal_detInference Model/Training Model 98.21 74.75 / 67.72 382.55 / 382.55 109 PP-OCRv4 server-side seal text detection model, with higher accuracy, suitable for deployment on better servers
PP-OCRv4_mobile_seal_detInference Model/Training Model 96.47 7.82 / 3.09 48.28 / 23.97 4.6 PP-OCRv4 mobile-side seal text detection model, with higher efficiency, suitable for deployment on the edge

Text Recognition Module:

ModelModel Download Link Recognition Avg Accuracy(%) GPU Inference Time (ms)
[Normal Mode / High-Performance Mode]
CPU Inference Time (ms)
[Normal Mode / High-Performance Mode]
Model Storage Size (M) Introduction
PP-OCRv4_server_rec_docInference Model/Training Model 81.53 6.65 / 2.38 32.92 / 32.92 74.7 M PP-OCRv4_server_rec_doc is trained on a mixed dataset of more Chinese document data and PP-OCR training data based on PP-OCRv4_server_rec. It has added the ability to recognize some traditional Chinese characters, Japanese, and special characters, and can support the recognition of more than 15,000 characters. In addition to improving the text recognition capability related to documents, it also enhances the general text recognition capability.
PP-OCRv4_mobile_recInference Model/Training Model 78.74 4.82 / 1.20 16.74 / 4.64 10.6 M The lightweight recognition model of PP-OCRv4 has high inference efficiency and can be deployed on various hardware devices, including edge devices.
PP-OCRv4_server_recInference Model/Training Model 80.61 6.58 / 2.43 33.17 / 33.17 71.2 M The server-side model of PP-OCRv4 offers high inference accuracy and can be deployed on various types of servers.
en_PP-OCRv4_mobile_recInference Model/Training Model 70.39 4.81 / 0.75 16.10 / 5.31 6.8 M The ultra-lightweight English recognition model, trained based on the PP-OCRv4 recognition model, supports the recognition of English letters and numbers.

The above list features the 4 core models that the text recognition module primarily supports. In total, this module supports 18 models. The complete list of models is as follows:

👉Model List Details
  • Chinese Recognition Model
ModelModel Download Link Recognition Avg Accuracy(%) CPU Inference Time (ms)
[Normal Mode / High-Performance Mode]
CPU Inference Time (ms)
[Normal Mode / High-Performance Mode]
Model Storage Size (M) Introduction
PP-OCRv4_server_rec_docInference Model/Training Model 81.53 6.65 / 2.38 32.92 / 32.92 74.7 M PP-OCRv4_server_rec_doc is trained on a mixed dataset of more Chinese document data and PP-OCR training data based on PP-OCRv4_server_rec. It has added the recognition capabilities for some traditional Chinese characters, Japanese, and special characters. The number of recognizable characters is over 15,000. In addition to the improvement in document-related text recognition, it also enhances the general text recognition capability.
PP-OCRv4_mobile_recInference Model/Training Model 78.74 4.82 / 1.20 16.74 / 4.64 10.6 M The lightweight recognition model of PP-OCRv4 has high inference efficiency and can be deployed on various hardware devices, including edge devices.
PP-OCRv4_server_rec Inference Model/Training Model 80.61 6.58 / 2.43 33.17 / 33.17 71.2 M The server-side model of PP-OCRv4 offers high inference accuracy and can be deployed on various types of servers.
PP-OCRv3_mobile_recInference Model/Training Model 72.96 5.87 / 1.19 9.07 / 4.28 9.2 M PP-OCRv3s lightweight recognition model is designed for high inference efficiency and can be deployed on a variety of hardware devices, including edge devices.
ModelModel Download Link Recognition Avg Accuracy(%) GPU Inference Time (ms)
[Normal Mode / High-Performance Mode]
CPU Inference Time (ms)
[Normal Mode / High-Performance Mode]
Model Storage Size (M) Introduction
ch_SVTRv2_recInference Model/Training Model 68.81 8.08 / 2.74 50.17 / 42.50 73.9 M SVTRv2 is a server text recognition model developed by the OpenOCR team of Fudan University's Visual and Learning Laboratory (FVL). It won the first prize in the PaddleOCR Algorithm Model Challenge - Task One: OCR End-to-End Recognition Task. The end-to-end recognition accuracy on the A list is 6% higher than that of PP-OCRv4.
ModelModel Download Link Recognition Avg Accuracy(%) GPU Inference Time (ms)
[Normal Mode / High-Performance Mode]
CPU Inference Time (ms)
[Normal Mode / High-Performance Mode]
Model Storage Size (M) Introduction
ch_RepSVTR_recInference Model/Training Model 65.07 5.93 / 1.62 20.73 / 7.32 22.1 M The RepSVTR text recognition model is a mobile text recognition model based on SVTRv2. It won the first prize in the PaddleOCR Algorithm Model Challenge - Task One: OCR End-to-End Recognition Task. The end-to-end recognition accuracy on the B list is 2.5% higher than that of PP-OCRv4, with the same inference speed.
  • English Recognition Model
ModelModel Download Link Recognition Avg Accuracy(%) GPU Inference Time (ms)
[Normal Mode / High-Performance Mode]
CPU Inference Time (ms)
[Normal Mode / High-Performance Mode]
Model Storage Size (M) Introduction
en_PP-OCRv4_mobile_recInference Model/Training Model 70.39 4.81 / 0.75 16.10 / 5.31 6.8 M The ultra-lightweight English recognition model trained based on the PP-OCRv4 recognition model supports the recognition of English and numbers.
en_PP-OCRv3_mobile_recInference Model/Training Model 70.69 5.44 / 0.75 8.65 / 5.57 7.8 M The ultra-lightweight English recognition model trained based on the PP-OCRv3 recognition model supports the recognition of English and numbers.
  • Multilingual Recognition Model
ModelModel Download Link Recognition Avg Accuracy(%) GPU Inference Time (ms)
[Normal Mode / High-Performance Mode]
CPU Inference Time (ms)
[Normal Mode / High-Performance Mode]
Model Storage Size (M) Introduction
korean_PP-OCRv3_mobile_recInference Model/Training Model 60.21 5.40 / 0.97 9.11 / 4.05 8.6 M The ultra-lightweight Korean recognition model trained based on the PP-OCRv3 recognition model supports the recognition of Korean and numbers.
japan_PP-OCRv3_mobile_recInference Model/Training Model 45.69 5.70 / 1.02 8.48 / 4.07 8.8 M The ultra-lightweight Japanese recognition model trained based on the PP-OCRv3 recognition model supports the recognition of Japanese and numbers.
chinese_cht_PP-OCRv3_mobile_recInference Model/Training Model 82.06 5.90 / 1.28 9.28 / 4.34 9.7 M The ultra-lightweight Traditional Chinese recognition model trained based on the PP-OCRv3 recognition model supports the recognition of Traditional Chinese and numbers.
te_PP-OCRv3_mobile_recInference Model/Training Model 95.88 5.42 / 0.82 8.10 / 6.91 7.8 M The ultra-lightweight Telugu recognition model trained based on the PP-OCRv3 recognition model supports the recognition of Telugu and numbers.
ka_PP-OCRv3_mobile_recInference Model/Training Model 96.96 5.25 / 0.79 9.09 / 3.86 8.0 M The ultra-lightweight Kannada recognition model trained based on the PP-OCRv3 recognition model supports the recognition of Kannada and numbers.
ta_PP-OCRv3_mobile_recInference Model/Training Model 76.83 5.23 / 0.75 10.13 / 4.30 8.0 M The ultra-lightweight Tamil recognition model trained based on the PP-OCRv3 recognition model supports the recognition of Tamil and numbers.
latin_PP-OCRv3_mobile_recInference Model/Training Model 76.93 5.20 / 0.79 8.83 / 7.15 7.8 M The ultra-lightweight Latin recognition model trained based on the PP-OCRv3 recognition model supports the recognition of Latin script and numbers.
arabic_PP-OCRv3_mobile_recInference Model/Training Model 73.55 5.35 / 0.79 8.80 / 4.56 7.8 M The ultra-lightweight Arabic script recognition model trained based on the PP-OCRv3 recognition model supports the recognition of Arabic script and numbers.
cyrillic_PP-OCRv3_mobile_recInference Model/Training Model 94.28 5.23 / 0.76 8.89 / 3.88 7.9 M The ultra-lightweight cyrillic alphabet recognition model trained based on the PP-OCRv3 recognition model supports the recognition of cyrillic letters and numbers.
devanagari_PP-OCRv3_mobile_recInference Model/Training Model 96.44 5.22 / 0.79 8.56 / 4.06 7.9 M The ultra-lightweight Devanagari script recognition model trained based on the PP-OCRv3 recognition model supports the recognition of Devanagari script and numbers.

Test Environment Description:

  • Performance Test Environment
    • Test Dataset
      • Document Image Orientation Classification Module: A self-built dataset using PaddleX, covering multiple scenarios such as ID cards and documents, containing 1000 images.
      • Text Image Rectification Model: DocUNet
      • Layout Detection Model: A self-built layout detection dataset using PaddleOCR, including 500 images of common document types such as Chinese and English papers, magazines, contracts, books, exam papers, and research reports.
      • 3-Category Layout Detection Model: A self-built layout detection dataset using PaddleOCR, containing 1154 images of common document types such as Chinese and English papers, magazines, and research reports.
      • 17-Category Region Detection Model: A self-built layout detection dataset using PaddleOCR, including 892 images of common document types such as Chinese and English papers, magazines, and research reports.
      • Text Detection Model: A self-built Chinese dataset using PaddleOCR, covering multiple scenarios such as street scenes, web images, documents, and handwriting, with 500 images for detection.
      • Chinese Recognition Model: A self-built Chinese dataset using PaddleOCR, covering multiple scenarios such as street scenes, web images, documents, and handwriting, with 11,000 images for text recognition.
      • ch_SVTRv2_rec: Evaluation set A for "OCR End-to-End Recognition Task" in the PaddleOCR Algorithm Model Challenge
      • ch_RepSVTR_rec: Evaluation set B for "OCR End-to-End Recognition Task" in the PaddleOCR Algorithm Model Challenge.
      • English Recognition Model: A self-built English dataset using PaddleX.
      • Multilingual Recognition Model: A self-built multilingual dataset using PaddleX.
      • Text Line Orientation Classification Model: A self-built dataset using PaddleX, covering various scenarios such as ID cards and documents, containing 1000 images.
      • Seal Text Detection Model: A self-built dataset using PaddleX, containing 500 images of circular seal textures.
    • Hardware Configuration
      • GPU: NVIDIA Tesla T4
      • CPU: Intel Xeon Gold 6271C @ 2.60GHz
      • Other Environments: Ubuntu 20.04 / cuDNN 8.6 / TensorRT 8.5.2.2
  • Inference Mode 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.)

2. Quick Start

Before using the seal text recognition production line locally, please ensure that you have completed the installation of the wheel package according to the installation tutorial. Once the installation is complete, you can experience it locally via the command line or integrate it with Python.

2.1 命令行方式体验

You can quickly experience the seal_recognition production line effect with a single command:

paddleocr seal_recognition -i https://paddle-model-ecology.bj.bcebos.com/paddlex/imgs/demo_image/seal_text_det.png

# Specify whether to use the document orientation classification model with --use_doc_orientation_classify
paddleocr seal_recognition -i ./seal_text_det.png --use_doc_orientation_classify True

# Specify whether to use the text image correction module with --use_doc_unwarping.
paddleocr seal_recognition -i ./seal_text_det.png --use_doc_unwarping True

# Use --device to specify the use of GPU for model inference.
paddleocr seal_recognition -i ./seal_text_det.png --device gpu

After running, the results will be printed to the terminal, as follows:

👉Click to Expand
{'res': {'input_path': 'seal_text_det.png', 'model_settings': {'use_doc_preprocessor': False, 'use_layout_detection': True}, 'layout_det_res': {'input_path': None, 'page_index': None, 'boxes': [{'cls_id': 16, 'label': 'seal', 'score': 0.975531280040741, 'coordinate': [6.195526, 0.1579895, 634.3982, 628.84595]}]}, 'seal_res_list': [{'input_path': None, 'page_index': None, 'model_settings': {'use_doc_preprocessor': False, 'use_textline_orientation': False}, 'dt_polys': [array([[320,  38],
       ...,
       [315,  38]]), array([[461, 347],
       ...,
       [456, 346]]), array([[439, 445],
       ...,
       [434, 444]]), array([[158, 468],
       ...,
       [154, 466]])], 'text_det_params': {'limit_side_len': 736, 'limit_type': 'min', 'thresh': 0.2, 'box_thresh': 0.6, 'unclip_ratio': 0.5}, 'text_type': 'seal', 'textline_orientation_angles': array([-1, ..., -1]), 'text_rec_score_thresh': 0, 'rec_texts': ['天津君和缘商贸有限公司', '发票专用章', '吗繁物', '5263647368706'], 'rec_scores': array([0.9934051 , ..., 0.99139398]), 'rec_polys': [array([[320,  38],
       ...,
       [315,  38]]), array([[461, 347],
       ...,
       [456, 346]]), array([[439, 445],
       ...,
       [434, 444]]), array([[158, 468],
       ...,
       [154, 466]])], 'rec_boxes': array([], dtype=float64)}]}}

The explanation of the result parameters can be found in 2.1.2 Python Script Integration.

The visualized results are saved under save_path, and the visualized result of seal OCR is as follows:

2.2.2 Python Script Integration

  • The above command line is for quickly experiencing and viewing the effect. Generally, in a project, you often need to integrate through code. You can complete the quick inference of the pipeline with just a few lines of code. The inference code is as follows:
from paddlex import create_pipeline

pipeline = create_pipeline(pipeline="seal_recognition")

output = pipeline.predict(
    "seal_text_det.png",
    use_doc_orientation_classify=False,
    use_doc_unwarping=False,
)
for res in output:
    res.print()
    res.save_to_img("./output/")
    res.save_to_json("./output/")

In the above Python script, the following steps were executed:

(1) The seal recognition pipeline object was instantiated via create_pipeline(), with the specific parameters described as follows:

Parameter Description Type Default Value
pipeline The name of the pipeline or the path to the pipeline configuration file. If it is a pipeline name, it must be supported by PaddleX. str None
config Specific configuration information for the pipeline (if set simultaneously with pipeline, it has higher priority than pipeline, and the pipeline name must be consistent with pipeline). dict[str, Any] None
device The device used for pipeline inference. It supports specifying the specific card number of the GPU, such as "gpu:0", other hardware card numbers, such as "npu:0", or CPU, such as "cpu". Supports specifying multiple devices simultaneously for parallel inference. For details, please refer to Pipeline Parallel Inference. str gpu:0
use_hpip Whether to enable the high-performance inference plugin. If set to None, the setting from the configuration file or config will be used. bool None None
hpi_config High-performance inference configuration dict | None None None

(2) Call the predict() method of the Seal Text Recognition pipeline object for inference prediction. This method will return a generator. Below are the parameters and their descriptions for the predict() method:

Parameter Description Type Options Default Value
input Data to be predicted, supports multiple input types (required) Python Var|str|list
  • Python Var: Image data represented by numpy.ndarray
  • str: Local path of an image or PDF file, e.g., /root/data/img.jpg; URL link, e.g., the network URL of an image or PDF file: Example; Local directory, containing images to be predicted, e.g., /root/data/ (currently does not support prediction of PDF files in directories; PDF files must be specified with an exact file path)
  • List: Elements of the list must be of the above types, e.g., [numpy.ndarray, numpy.ndarray], [\"/root/data/img1.jpg\", \"/root/data/img2.jpg\"], [\"/root/data1\", \"/root/data2\"]
None
device Inference device for the pipeline str|None
  • CPU: e.g., cpu for CPU inference;
  • GPU: e.g., gpu:0 for inference using the first GPU;
  • NPU: e.g., npu:0 for inference using the first NPU;
  • XPU: e.g., xpu:0 for inference using the first XPU;
  • MLU: e.g., mlu:0 for inference using the first MLU;
  • DCU: e.g., dcu:0 for inference using the first DCU;
  • None: If set to None, the default value from the pipeline initialization will be used. During initialization, the local GPU device 0 will be prioritized; if unavailable, the CPU device will be used.
None
use_doc_orientation_classify Whether to use the document orientation classification module bool|None
  • bool: True or False;
  • None: If set to None, the default value from the pipeline initialization will be used, initialized as True.
None
use_doc_unwarping Whether to use the document unwarping module bool|None
  • bool: True or False;
  • None: If set to None, the default value from the pipeline initialization will be used, initialized as True.
None
use_layout_detection Whether to use the layout detection module bool|None
  • bool: True or False;
  • None: If set to None, the default value from the pipeline initialization will be used, initialized as True.
None
layout_threshold Confidence threshold for layout detection; only scores above this threshold will be output float|dict|None
  • float: Any float greater than 0
  • dict: Key is the int category ID, value is any float greater than 0
  • None: If set to None, the default value from the pipeline initialization will be used, initialized as 0.5
None
layout_nms Whether to use Non-Maximum Suppression (NMS) for layout detection post-processing bool|None
  • bool: True or False;
  • None: If set to None, the default value from the pipeline initialization will be used, initialized as True.
None
layout_unclip_ratio Expansion ratio of detection box edges; if not specified, the default value from the PaddleX official model configuration will be used float|list|None
  • float: Any float greater than 0, e.g., 1.1, which means expanding the width and height of the detection box by 1.1 times while keeping the center unchanged
  • list: e.g., [1.2, 1.5], which means expanding the width of the detection box by 1.2 times and the height by 1.5 times while keeping the center unchanged
  • None: If set to None, the default value from the pipeline initialization will be used, initialized as 1.0
layout_merge_bboxes_mode Merging mode for detection boxes in layout detection output; if not specified, the default value from the PaddleX official model configuration will be used string|None
  • large: When set to large, only the largest external box will be retained for overlapping detection boxes, and the internal overlapping boxes will be removed.
  • small: When set to small, only the smallest internal box will be retained for overlapping detection boxes, and the external overlapping boxes will be removed.
  • union: No filtering of boxes will be performed; both internal and external boxes will be retained.
  • None: If set to None, the default value from the pipeline initialization will be used, initialized as large.
None
seal_det_limit_side_len Side length limit for seal text detection int|None
  • int: Any integer greater than 0
  • None: If set to None, the default value from the pipeline initialization will be used, initialized as 736
None
seal_rec_score_thresh Text recognition threshold; text results with scores above this threshold will be retained float|None
  • float: Any float greater than 0
  • None: If set to None, the default value from the pipeline initialization will be used, initialized as 0.0. This means no threshold is applied.
None

(3) Process the prediction results. The prediction result for each sample is of dict type and supports operations such as printing, saving as an image, and saving as a json file:

Method Description Parameter Parameter Type Parameter Description Default Value
print() Print results 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 for better readability, effective only when format_json is True 4
ensure_ascii bool Control whether to escape non-ASCII characters to Unicode. When set to True, all non-ASCII characters will be escaped; False will retain the original characters, effective only when format_json is True False
save_to_json() Save results as a json file save_path str The file path to save the results. When it is a directory, the saved file name will be consistent with the input file type None
indent int Specify the indentation level to beautify the output JSON data for better readability, effective only when format_json is True 4
ensure_ascii bool Control whether to escape non-ASCII characters to Unicode. When set to True, all non-ASCII characters will be escaped; False will retain the original characters, effective only when format_json is True False
save_to_img() Save results as an image file save_path str The file path to save the results, supports directory or file path None
  • Calling the print() method will print the results to the terminal, and the explanations of the printed content are as follows:

    • input_path: (str) The input path of the image to be predicted.

    • model_settings: (Dict[str, bool]) The model parameters required for pipeline configuration.

      • use_doc_preprocessor: (bool) Controls whether to enable the document preprocessing sub-pipeline.
      • use_layout_detection: (bool) Controls whether to enable the layout detection sub-module.
    • layout_det_res: (Dict[str, Union[List[numpy.ndarray], List[float]]]) The output result of the layout detection sub-module. Only exists when use_layout_detection=True.

      • input_path: (Union[str, None]) The image path accepted by the layout detection module. Saved as None when the input is a numpy.ndarray.
      • page_index: (Union[int, None]) Indicates the current page number of the PDF if the input is a PDF file; otherwise, it is None.
      • boxes: (List[Dict]) A list of detected layout seal regions, with each element containing the following fields:
        • cls_id: (int) The class ID of the detected seal region.
        • score: (float) The confidence score of the detected region.
        • coordinate: (List[float]) The coordinates of the four corners of the detection box, in the order of x1, y1, x2, y2, representing the x-coordinate of the top-left corner, the y-coordinate of the top-left corner, the x-coordinate of the bottom-right corner, and the y-coordinate of the bottom-right corner.
    • seal_res_list: List[Dict] A list of seal text recognition results, with each element containing the following fields:

      • input_path: (Union[str, None]) The image path accepted by the seal text recognition pipeline. Saved as None when the input is a numpy.ndarray.
      • page_index: (Union[int, None]) Indicates the current page number of the PDF if the input is a PDF file; otherwise, it is None.
      • model_settings: (Dict[str, bool]) The model configuration parameters for the seal text recognition pipeline.
        • use_doc_preprocessor: (bool) Controls whether to enable the document preprocessing sub-pipeline.
        • use_textline_orientation: (bool) Controls whether to enable the text line orientation classification sub-module.
    • doc_preprocessor_res: (Dict[str, Union[str, Dict[str, bool], int]]) The output result of the document preprocessing sub-pipeline. Only exists when use_doc_preprocessor=True.

      • input_path: (Union[str, None]) The image path accepted by the document preprocessing sub-pipeline. Saved as None when the input is a numpy.ndarray.
      • model_settings: (Dict) The model configuration parameters for the preprocessing sub-pipeline.
        • use_doc_orientation_classify: (bool) Controls whether to enable document orientation classification.
        • use_doc_unwarping: (bool) Controls whether to enable document unwarping.
      • angle: (int) The predicted result of document orientation classification. When enabled, it takes values [0, 1, 2, 3], corresponding to [0°, 90°, 180°, 270°]; when disabled, it is -1.
    • dt_polys: (List[numpy.ndarray]) A list of polygon boxes for seal text detection. Each detection box is represented by a numpy array of multiple vertex coordinates, with the array shape being (n, 2).

    • dt_scores: (List[float]) A list of confidence scores for text detection boxes.

    • text_det_params: (Dict[str, Dict[str, int, float]]) Configuration parameters for the text detection module.

      • limit_side_len: (int) The side length limit value during image preprocessing.
      • limit_type: (str) The handling method for side length limits.
      • thresh: (float) The confidence threshold for text pixel classification.
      • box_thresh: (float) The confidence threshold for text detection boxes.
      • unclip_ratio: (float) The expansion ratio for text detection boxes.
      • text_type: (str) The type of seal text detection, currently fixed as "seal".
    • text_rec_score_thresh: (float) The filtering threshold for text recognition results.

    • rec_texts: (List[str]) A list of text recognition results, containing only texts with confidence scores above text_rec_score_thresh.

    • rec_scores: (List[float]) A list of confidence scores for text recognition, filtered by text_rec_score_thresh.

    • rec_polys: (List[numpy.ndarray]) A list of text detection boxes filtered by confidence score, in the same format as dt_polys.

    • rec_boxes: (numpy.ndarray) An array of rectangular bounding boxes for detection boxes; the seal recognition pipeline returns an empty array.

  • Calling the save_to_json() method will save the above content to the specified save_path. If a directory is specified, the saved path will be save_path/{your_img_basename}_res.json. If a file is specified, it will be saved directly to that file. Since JSON files do not support saving numpy arrays, numpy.array types will be converted to list format.

  • Calling the save_to_img() method will save the visualization results to the specified save_path. If a directory is specified, the saved path will be save_path/{your_img_basename}_seal_res_region1.{your_img_extension}. If a file is specified, it will be saved directly to that file. (The pipeline usually contains multiple result images, so it is not recommended to specify a specific file path directly, as multiple images will be overwritten, and only the last image will be retained.)

  • Additionally, you can obtain visualized images with results and prediction results through attributes, as follows:
Attribute Description
json Get the prediction results in json format.
img Get the visualization results in dict format.
  • The prediction results obtained through the json attribute are of dict type, with content consistent with what is saved by calling the save_to_json() method.
  • The prediction results returned by the img attribute are of dict type. The keys are layout_det_res, seal_res_region1, and preprocessed_img, corresponding to three Image.Image objects: one for visualizing layout detection, one for visualizing seal text recognition results, and one for visualizing image preprocessing. If the image preprocessing sub-module is not used, preprocessed_img will not be included in the dictionary. If the layout region detection module is not used, layout_det_res will not be included.

Additionally, you can obtain the configuration file for the seal text recognition pipeline and load the configuration file for prediction. You can execute the following command to save the results in my_path:

paddlex --get_pipeline_config seal_recognition --save_path ./my_path

If you have obtained the configuration file, you can customize the settings for the seal text recognition pipeline by simply modifying the pipeline parameter value in the create_pipeline method to the path of the pipeline configuration file. The example is as follows:

from paddlex import create_pipeline
pipeline = create_pipeline(pipeline="./my_path/seal_recognition.yaml")
output = pipeline.predict("seal_text_det.png")
for res in output:
    res.print() ## 打印预测的结构化输出
    res.save_to_img("./output/") ## 保存可视化结果
    res.save_to_json("./output/") ## 保存预测结果的json文件

(1) Instantiate the seal text recognition production object through SealRecognition(). The specific parameter descriptions are as follows:

Here's the translation of the table into English:

Parameter Description Type Default Value
doc_orientation_classify_model_name Name of the document orientation classification model. If set to None, the default model will be used. str None
doc_orientation_classify_model_dir Directory path of the document orientation classification model. If set to None, the official model will be downloaded. str None
doc_unwarping_model_name Name of the text image correction model. If set to None, the default model will be used. str None
doc_unwarping_model_dir Directory path of the text image correction model. If set to None, the official model will be downloaded. str None
layout_detection_model_name Name of the layout detection model. If set to None, the default model will be used. str None
layout_detection_model_dir Directory path of the layout detection model. If set to None, the official model will be downloaded. str None
seal_text_detection_model_name Name of the seal text detection model. If set to None, the default model will be used. str None
seal_text_detection_model_dir Directory path of the seal text detection model. If set to None, the official model will be downloaded. str None
text_recognition_model_name Name of the text recognition model. If set to None, the default model will be used. str None
text_recognition_model_dir Directory path of the text recognition model. If set to None, the official model will be downloaded. str None
text_recognition_batch_size Batch size for the text recognition model. If set to None, the default batch size is 1. int None
use_doc_orientation_classify Whether to load the document orientation classification module. If set to None, the default value initialized by the production line will be used, initialized to True. bool None
use_doc_unwarping Whether to load the text image correction module. If set to None, the default value initialized by the production line will be used, initialized to True. bool None
use_layout_detection Whether to load the layout detection module. If set to None, the default value initialized by the production line will be used, initialized to True. bool None
layout_threshold Layout detection confidence threshold; only scores greater than this threshold will be output.
  • float: Any floating point number greater than 0
  • dict: Keys are int category IDs, values are any floating point number greater than 0
  • None: If set to None, the default value initialized by the production line, 0.5, will be used
float|dict None
layout_nms Whether to use post-processing NMS in layout detection. If set to None, the default value initialized by the production line, initialized to True, will be used. bool None
layout_unclip_ratio Scale factor for the sides of the detection box.
  • float: A floating point number greater than 0, e.g., 1.1, indicates that the width and height of the detection box output by the model will be expanded by 1.1 times, keeping the center unchanged
  • list: e.g., [1.2, 1.5], indicates that the width will be expanded by 1.2 times and the height by 1.5 times, keeping the center unchanged
  • None: If set to None, the default value initialized by the production line, initialized to 1.0, will be used
float|list None
layout_merge_bboxes_mode Mode for merging detection boxes output by the model in layout detection.
  • large: When set to large, only the largest external box will be retained for overlapping detection boxes, and overlapping internal boxes will be deleted
  • small: When set to small, only the small internal box will be retained, and overlapping external boxes will be deleted
  • union: No filtering will be performed, and both internal and external boxes will be retained
  • None: If set to None, the default value initialized by the production line, initialized to large, will be used
str None
seal_det_limit_side_len Image side length limit for seal text detection.
  • int: Any integer greater than 0
  • None: If set to None, the default value initialized by the production line, initialized to 736, will be used
int None
seal_det_limit_type Image side length limit type for seal text detection.
  • str: Supports min and max; min ensures that the shortest side of the image is not less than det_limit_side_len, while max ensures that the longest side of the image is not greater than limit_side_len
  • None: If set to None, the default value initialized by the production line, initialized to min, will be used
str None
seal_det_thresh Detection pixel threshold; only pixels with scores greater than this threshold in the output probability map will be considered as text pixels.
  • float: Any floating point number greater than 0
  • None: If set to None, the default value initialized by the production line, 0.2, will be used
float None
seal_det_box_thresh Detection box threshold; when the average score of all pixels within a detection result box is greater than this threshold, the result is considered a text area.
  • float: Any floating point number greater than 0
  • None: If set to None, the default value initialized by the production line, 0.6, will be used
float None
seal_det_unclip_ratio Seal text detection expansion coefficient; the larger the value, the greater the expansion area.
  • float: Any floating point number greater than 0
  • None: If set to None, the default value initialized by the production line, 0.5, will be used
float None
seal_rec_score_thresh Text recognition threshold; text results with scores greater than this threshold will be retained.
  • float: Any floating point number greater than 0
  • None: If set to None, the default value initialized by the production line, 0.0, will be used, meaning no threshold is set
float None
device The device used for inference. Supports specifying a specific card number.
  • CPU: e.g., cpu indicates using the CPU for inference
  • GPU: e.g., gpu:0 indicates using the first GPU for inference
  • NPU: e.g., npu:0 indicates using the first NPU for inference
  • XPU: e.g., xpu:0 indicates using the first XPU for inference
  • MLU: e.g., mlu:0 indicates using the first MLU for inference
  • DCU: e.g., dcu:0 indicates using the first DCU for inference
  • None: If set to None, the default value initialized by the production line will be used, which will prioritize using local GPU 0 if available, otherwise it will use the CPU
str None
enable_hpi Whether to enable high-performance inference. bool False
use_tensorrt Whether to use TensorRT for inference acceleration. bool False
min_subgraph_size Minimum subgraph size, used for optimizing model subgraph computation. int 3
precision Computation precision, such as fp32 or fp16. str fp32
enable_mkldnn Whether to enable the MKL-DNN acceleration library. If set to None, it will be enabled by default. bool None
cpu_threads The number of threads to use when performing inference on the CPU. int 8

(2) Call the predict() method of the seal text recognition production object for inference prediction. This method will return a list of results.

Additionally, the production line also offers the predict_iter() method. Both methods are identical in terms of parameter acceptance and result return; the difference lies in that predict_iter() returns a generator, allowing for gradual processing and retrieval of prediction results. This is suitable for handling large datasets or scenarios where memory saving is desired. You can choose either method based on your actual needs.

Below are the parameters for the predict() method and their descriptions:

Parameter Description Type Options Default Value
input Data to be predicted, supports multiple input types (required) Python Var|str|list
  • Python Var: Image data represented by numpy.ndarray
  • str: Local path of an image or PDF file, e.g., /root/data/img.jpg; URL link, e.g., the network URL of an image or PDF file: Example; Local directory, containing images to be predicted, e.g., /root/data/ (currently does not support prediction of PDF files in directories; PDF files must be specified with an exact file path)
  • List: Elements of the list must be of the above types, e.g., [numpy.ndarray, numpy.ndarray], [\"/root/data/img1.jpg\", \"/root/data/img2.jpg\"], [\"/root/data1\", \"/root/data2\"]
None
device Inference device for the pipeline str|None
  • CPU: e.g., cpu for CPU inference;
  • GPU: e.g., gpu:0 for inference using the first GPU;
  • NPU: e.g., npu:0 for inference using the first NPU;
  • XPU: e.g., xpu:0 for inference using the first XPU;
  • MLU: e.g., mlu:0 for inference using the first MLU;
  • DCU: e.g., dcu:0 for inference using the first DCU;
  • None: If set to None, the default value from the pipeline initialization will be used. During initialization, the local GPU device 0 will be prioritized; if unavailable, the CPU device will be used.
None
use_doc_orientation_classify Whether to use the document orientation classification module bool|None
  • bool: True or False;
  • None: If set to None, the default value from the pipeline initialization will be used, initialized as True.
None
use_doc_unwarping Whether to use the document unwarping module bool|None
  • bool: True or False;
  • None: If set to None, the default value from the pipeline initialization will be used, initialized as True.
None
use_layout_detection Whether to use the layout detection module bool|None
  • bool: True or False;
  • None: If set to None, the default value from the pipeline initialization will be used, initialized as True.
None
layout_threshold Confidence threshold for layout detection; only scores above this threshold will be output float|dict|None
  • float: Any float greater than 0
  • dict: Key is the int category ID, value is any float greater than 0
  • None: If set to None, the default value from the pipeline initialization will be used, initialized as 0.5
None
layout_nms Whether to use Non-Maximum Suppression (NMS) for layout detection post-processing bool|None
  • bool: True or False;
  • None: If set to None, the default value from the pipeline initialization will be used, initialized as True.
None
layout_unclip_ratio Expansion ratio of detection box edges; if not specified, the default value from the PaddleX official model configuration will be used float|list|None
  • float: Any float greater than 0, e.g., 1.1, which means expanding the width and height of the detection box by 1.1 times while keeping the center unchanged
  • list: e.g., [1.2, 1.5], which means expanding the width of the detection box by 1.2 times and the height by 1.5 times while keeping the center unchanged
  • None: If set to None, the default value from the pipeline initialization will be used, initialized as 1.0
layout_merge_bboxes_mode Merging mode for detection boxes in layout detection output; if not specified, the default value from the PaddleX official model configuration will be used string|None
  • large: When set to large, only the largest external box will be retained for overlapping detection boxes, and the internal overlapping boxes will be removed.
  • small: When set to small, only the smallest internal box will be retained for overlapping detection boxes, and the external overlapping boxes will be removed.
  • union: No filtering of boxes will be performed; both internal and external boxes will be retained.
  • None: If set to None, the default value from the pipeline initialization will be used, initialized as large.
None
seal_det_limit_side_len Side length limit for seal text detection int|None
  • int: Any integer greater than 0
  • None: If set to None, the default value from the pipeline initialization will be used, initialized as 736
None
seal_rec_score_thresh Text recognition threshold; text results with scores above this threshold will be retained float|None
  • float: Any float greater than 0
  • None: If set to None, the default value from the pipeline initialization will be used, initialized as 0.0. This means no threshold is applied.
None

(3) Process the prediction results. The prediction result for each sample is of dict type and supports operations such as printing, saving as an image, and saving as a json file:

Method Description Parameter Parameter Type Parameter Description Default Value
print() Print results 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 for better readability, effective only when format_json is True 4
ensure_ascii bool Control whether to escape non-ASCII characters to Unicode. When set to True, all non-ASCII characters will be escaped; False will retain the original characters, effective only when format_json is True False
save_to_json() Save results as a json file save_path str The file path to save the results. When it is a directory, the saved file name will be consistent with the input file type None
indent int Specify the indentation level to beautify the output JSON data for better readability, effective only when format_json is True 4
ensure_ascii bool Control whether to escape non-ASCII characters to Unicode. When set to True, all non-ASCII characters will be escaped; False will retain the original characters, effective only when format_json is True False
save_to_img() Save results as an image file save_path str The file path to save the results, supports directory or file path None

Note: The parameters in the configuration file are the pipeline initialization parameters. If you wish to change the initialization parameters of the seal text recognition pipeline, you can directly modify the parameters in the configuration file and load the configuration file for prediction. Additionally, CLI prediction also supports passing in a configuration file. Simply specify the path of the configuration file with --pipeline.

  • Calling the print() method will print the results to the terminal, and the explanations of the printed content are as follows:

    • input_path: (str) The input path of the image to be predicted.

    • model_settings: (Dict[str, bool]) The model parameters required for pipeline configuration.

      • use_doc_preprocessor: (bool) Controls whether to enable the document preprocessing sub-pipeline.
      • use_layout_detection: (bool) Controls whether to enable the layout detection sub-module.
    • layout_det_res: (Dict[str, Union[List[numpy.ndarray], List[float]]]) The output result of the layout detection sub-module. Only exists when use_layout_detection=True.

      • input_path: (Union[str, None]) The image path accepted by the layout detection module. Saved as None when the input is a numpy.ndarray.
      • page_index: (Union[int, None]) Indicates the current page number of the PDF if the input is a PDF file; otherwise, it is None.
      • boxes: (List[Dict]) A list of detected layout seal regions, with each element containing the following fields:
        • cls_id: (int) The class ID of the detected seal region.
        • score: (float) The confidence score of the detected region.
        • coordinate: (List[float]) The coordinates of the four corners of the detection box, in the order of x1, y1, x2, y2, representing the x-coordinate of the top-left corner, the y-coordinate of the top-left corner, the x-coordinate of the bottom-right corner, and the y-coordinate of the bottom-right corner.
    • seal_res_list: List[Dict] A list of seal text recognition results, with each element containing the following fields:

      • input_path: (Union[str, None]) The image path accepted by the seal text recognition pipeline. Saved as None when the input is a numpy.ndarray.
      • page_index: (Union[int, None]) Indicates the current page number of the PDF if the input is a PDF file; otherwise, it is None.
      • model_settings: (Dict[str, bool]) The model configuration parameters for the seal text recognition pipeline.
        • use_doc_preprocessor: (bool) Controls whether to enable the document preprocessing sub-pipeline.
        • use_textline_orientation: (bool) Controls whether to enable the text line orientation classification sub-module.
    • doc_preprocessor_res: (Dict[str, Union[str, Dict[str, bool], int]]) The output result of the document preprocessing sub-pipeline. Only exists when use_doc_preprocessor=True.

      • input_path: (Union[str, None]) The image path accepted by the document preprocessing sub-pipeline. Saved as None when the input is a numpy.ndarray.
      • model_settings: (Dict) The model configuration parameters for the preprocessing sub-pipeline.
        • use_doc_orientation_classify: (bool) Controls whether to enable document orientation classification.
        • use_doc_unwarping: (bool) Controls whether to enable document unwarping.
      • angle: (int) The predicted result of document orientation classification. When enabled, it takes values [0, 1, 2, 3], corresponding to [0°, 90°, 180°, 270°]; when disabled, it is -1.
    • dt_polys: (List[numpy.ndarray]) A list of polygon boxes for seal text detection. Each detection box is represented by a numpy array of multiple vertex coordinates, with the array shape being (n, 2).

    • dt_scores: (List[float]) A list of confidence scores for text detection boxes.

    • text_det_params: (Dict[str, Dict[str, int, float]]) Configuration parameters for the text detection module.

      • limit_side_len: (int) The side length limit value during image preprocessing.
      • limit_type: (str) The handling method for side length limits.
      • thresh: (float) The confidence threshold for text pixel classification.
      • box_thresh: (float) The confidence threshold for text detection boxes.
      • unclip_ratio: (float) The expansion ratio for text detection boxes.
      • text_type: (str) The type of seal text detection, currently fixed as "seal".
    • text_rec_score_thresh: (float) The filtering threshold for text recognition results.

    • rec_texts: (List[str]) A list of text recognition results, containing only texts with confidence scores above text_rec_score_thresh.

    • rec_scores: (List[float]) A list of confidence scores for text recognition, filtered by text_rec_score_thresh.

    • rec_polys: (List[numpy.ndarray]) A list of text detection boxes filtered by confidence score, in the same format as dt_polys.

    • rec_boxes: (numpy.ndarray) An array of rectangular bounding boxes for detection boxes; the seal recognition pipeline returns an empty array.

  • Calling the save_to_json() method will save the above content to the specified save_path. If a directory is specified, the saved path will be save_path/{your_img_basename}_res.json. If a file is specified, it will be saved directly to that file. Since JSON files do not support saving numpy arrays, numpy.array types will be converted to list format.

  • Calling the save_to_img() method will save the visualization results to the specified save_path. If a directory is specified, the saved path will be save_path/{your_img_basename}_seal_res_region1.{your_img_extension}. If a file is specified, it will be saved directly to that file. (The pipeline usually contains multiple result images, so it is not recommended to specify a specific file path directly, as multiple images will be overwritten, and only the last image will be retained.)

  • Additionally, you can obtain visualized images with results and prediction results through attributes, as follows:
Attribute Description
json Get the prediction results in json format.
img Get the visualization results in dict format.
  • The prediction results obtained through the json attribute are of dict type, with content consistent with what is saved by calling the save_to_json() method.
  • The prediction results returned by the img attribute are of dict type. The keys are layout_det_res, seal_res_region1, and preprocessed_img, corresponding to three Image.Image objects: one for visualizing layout detection, one for visualizing seal text recognition results, and one for visualizing image preprocessing. If the image preprocessing sub-module is not used, preprocessed_img will not be included in the dictionary. If the layout region detection module is not used, layout_det_res will not be included.

3. Development Integration/Deployment

If the pipeline meets your requirements for inference speed and accuracy, you can proceed directly with development integration/deployment.

If you need to integrate the pipeline into your Python project, you can refer to the example code in 2.2 Python Script Method.

In addition, PaddleX also provides three other deployment methods, which are detailed as follows:

🚀 High-Performance Inference: In real-world production environments, many applications have stringent performance requirements for deployment strategies, especially in terms of response speed, to ensure efficient system operation and a smooth user experience. To address this, PaddleOCR offers high-performance inference capabilities aimed at deeply optimizing the performance of model inference and pre/post-processing, thereby significantly accelerating the end-to-end process. For detailed high-performance inference procedures, please refer to the High-Performance Inference Guide.

☁️ Service Deployment: Service deployment is a common form of deployment in real-world production environments. By encapsulating inference functionality into a service, clients can access these services via network requests to obtain inference results. For detailed production service deployment procedures, please refer to the Service Deployment Guide.

Below are the API references for basic serving deployment and multi-language service invocation examples:

API Reference

For the main operations provided by the service:

  • The HTTP request method is POST.
  • The request body and response body are both JSON data (JSON objects).
  • When the request is processed successfully, the response status code is 200, and the attributes of the response body are as follows:
Name Type Description
logId string The UUID of the request.
errorCode integer Error code. Fixed as 0.
errorMsg string Error message. Fixed as "Success".
result object The result of the operation.
  • When the request is not processed successfully, the attributes of the response body are as follows:
Name Type Description
logId string The UUID of the request.
errorCode integer Error code. Same as the response status code.
errorMsg string Error message.

The main operations provided by the service are as follows:

  • infer

Obtain the seal text recognition result.

POST /seal-recognition

  • The attributes of the request body are as follows:
Name Type Description Required
file string The URL of an image or PDF file accessible by the server, or the Base64-encoded content of the file. By default, for PDF files exceeding 10 pages, only the content of the first 10 pages will be processed.
To remove the page limit, please add the following configuration to the pipeline configuration file:
Serving:
  extra:
    max_num_input_imgs: null
Yes
fileType integer | null The type of file. 0 indicates a PDF file, 1 indicates an image file. If this attribute is not present in the request body, the file type will be inferred from the URL. No
useDocOrientationClassify boolean | null Please refer to the description of the use_doc_orientation_classify parameter of the pipeline object's predict method. No
useDocUnwarping boolean | null Please refer to the description of the use_doc_unwarping parameter of the pipeline object's predict method. No
useLayoutDetection boolean | null Please refer to the description of the use_layout_detection parameter of the pipeline object's predict method. No
layoutThreshold number | null Please refer to the description of the layout_threshold parameter of the pipeline object's predict method. No
layoutNms boolean | null Please refer to the description of the layout_nms parameter of the pipeline object's predict method. No
layoutUnclipRatio number | array | null Please refer to the description of the layout_unclip_ratio parameter of the pipeline object's predict method. No
layoutMergeBboxesMode string | null Please refer to the description of the layout_merge_bboxes_mode parameter of the pipeline object's predict method. No
sealDetLimitSideLen integer | null Please refer to the description of the seal_det_limit_side_len parameter of the pipeline object's predict method. No
sealDetLimitType string | null Please refer to the description of the seal_det_limit_type parameter of the pipeline object's predict method. No
sealDetThresh number | null Please refer to the description of the seal_det_thresh parameter of the pipeline object's predict method. No
sealDetBoxThresh number | null Please refer to the description of the seal_det_box_thresh parameter of the pipeline object's predict method. No
sealDetUnclipRatio number | null Please refer to the description of the seal_det_unclip_ratio parameter of the pipeline object's predict method. No
sealRecScoreThresh number | null Please refer to the description of the seal_rec_score_thresh parameter of the pipeline object's predict method. No
  • When the request is processed successfully, the result in the response body has the following properties:
Name Type Meaning
sealRecResults object The seal text recognition result. The array length is 1 (for image input) or the actual number of document pages processed (for PDF input). For PDF input, each element in the array represents the result of each page actually processed in the PDF file.
dataInfo object Information about the input data.

Each element in sealRecResults is an object with the following properties:

Name Type Meaning
prunedResult object A simplified version of the res field in the JSON representation generated by the predict method of the production object, where the input_path and the page_index fields are removed.
outputImages object | null See the description of the img attribute of the result of the pipeline prediction. The images are in JPEG format and encoded in Base64.
inputImage string | null The input image. The image is in JPEG format and encoded in Base64.
Multi-language Service Invocation Example
Python
import base64
import requests

API_URL = "http://localhost:8080/seal-recognition"
file_path = "./demo.jpg"

with open(file_path, "rb") as file:
    file_bytes = file.read()
    file_data = base64.b64encode(file_bytes).decode("ascii")

payload = {"file": file_data, "fileType": 1}

response = requests.post(API_URL, json=payload)

assert response.status_code == 200
result = response.json()["result"]
for i, res in enumerate(result["sealRecResults"]):
    print(res["prunedResult"])
    for img_name, img in res["outputImages"].items():
        img_path = f"{img_name}_{i}.jpg"
        with open(img_path, "wb") as f:
            f.write(base64.b64decode(img))
        print(f"Output image saved at {img_path}")

4. Custom Development

If the default model weights provided by the seal text recognition pipeline do not meet your requirements in terms of accuracy or speed, you can try to fine-tune the existing models using your own domain-specific or application data to improve the recognition performance of the seal text recognition pipeline in your scenario.

Since the seal text recognition pipeline consists of several modules, if the pipeline's performance does not meet expectations, the issue may arise from any one of these modules. You can analyze images with poor recognition results to identify which module is problematic and refer to the corresponding fine-tuning tutorial links in the table below for model fine-tuning.

Scenario Fine-Tuning Module Fine-Tuning Reference Link
Inaccurate or missing seal position detection Layout Detection Module Link
Missing text detection Text Detection Module Link
Inaccurate text content Text Recognition Module Link
Inaccurate full-image rotation correction Document Image Orientation Classification Module Link
Inaccurate image distortion correction Text Image Correction Module Not supported for fine-tuning