PaddleOCR provides 2 service deployment methods:

Based on PaddleHub Serving: Code path is ./deploy/hubserving. Please follow this tutorial.
Based on PaddleServing: Code path is ./deploy/pdserving. Please refer to the tutorial for usage.

Service deployment based on PaddleHub Serving¶

The hubserving service deployment directory includes seven service packages: text detection, text angle class, text recognition, text detection+text angle class+text recognition three-stage series connection, layout analysis, table recognition, and PP-Structure. Please select the corresponding service package to install and start the service according to your needs. The directory is as follows:

deploy/hubserving/
  └─  ocr_det     text detection module service package
  └─  ocr_cls     text angle class module service package
  └─  ocr_rec     text recognition module service package
  └─  ocr_system  text detection+text angle class+text recognition three-stage series connection service package
  └─  structure_layout  layout analysis service package
  └─  structure_table  table recognition service package
  └─  structure_system  PP-Structure service package
  └─  kie_ser  KIE(SER) service package
  └─  kie_ser_re  KIE(SER+RE) service package

Each service pack contains 3 files. Take the 2-stage series connection service package as an example, the directory is as follows:

deploy/hubserving/ocr_system/
  └─  __init__.py    Empty file, required
  └─  config.json    Configuration file, optional, passed in as a parameter when using configuration to start the service
  └─  module.py      Main module file, required, contains the complete logic of the service
  └─  params.py      Parameter file, required, including parameters such as model path, pre and post-processing parameters

1. Update¶

2022.10.09 add KIE services.
2022.08.23 add layout analysis services.
2022.03.30 add PP-Structure and table recognition services.
2022.05.05 add PP-OCRv3 text detection and recognition services.

2. Quick start service¶

The following steps take the 2-stage series service as an example. If only the detection service or recognition service is needed, replace the corresponding file path.

2.1 Install PaddleHub¶

pip3 install paddlehub==2.1.0 --upgrade

2.2 Download inference model¶

Before installing the service module, you need to prepare the inference model and put it in the correct path. By default, the PP-OCRv3 models are used, and the default model path is:

Model	Path
text detection model	./inference/ch_PP-OCRv3_det_infer/
text recognition model	./inference/ch_PP-OCRv3_rec_infer/
text angle classifier	./inference/ch_ppocr_mobile_v2.0_cls_infer/
layout parse model	./inference/picodet_lcnet_x1_0_fgd_layout_infer/
tanle recognition	./inference/ch_ppstructure_mobile_v2.0_SLANet_infer/
KIE(SER)	./inference/ser_vi_layoutxlm_xfund_infer/
KIE(SER+RE)	./inference/re_vi_layoutxlm_xfund_infer/

The model path can be found and modified in params.py. More models provided by PaddleOCR can be obtained from the model library. You can also use models trained by yourself.

2.3 Install Service Module¶

PaddleOCR provides 5 kinds of service modules, install the required modules according to your needs.

On the Linux platform(replace / with \ if using Windows), the examples are as the following table:

2.4 Start service¶

2.4.1 Start with command line parameters (CPU only)¶

start command:

hub serving start --modules Module1==Version1, Module2==Version2, ... \
                  --port 8866 \
                  --use_multiprocess \
                  --workers \

Parameters: |parameters|usage| |---|---| |--modules/-m|PaddleHub Serving pre-installed model, listed in the form of multiple Module==Version key-value pairs
When Version is not specified, the latest version is selected by default| |--port/-p|Service port, default is 8866| |--use_multiprocess|Enable concurrent mode, by default using the single-process mode, this mode is recommended for multi-core CPU machines
Windows operating system only supports single-process mode| |--workers|The number of concurrent tasks specified in concurrent mode, the default is 2*cpu_count-1, where cpu_count is the number of CPU cores|

For example, start the 2-stage series service:

hub serving start -m ocr_system

This completes the deployment of a service API, using the default port number 8866.

2.4.2 Start with configuration file（CPU and GPU）¶

start command:

hub serving start --config/-c config.json

In which the format of config.json is as follows:

{
    "modules_info": {
        "ocr_system": {
            "init_args": {
                "version": "1.0.0",
                "use_gpu": true
            },
            "predict_args": {
            }
        }
    },
    "port": 8868,
    "use_multiprocess": false,
    "workers": 2
}

The configurable parameters in init_args are consistent with the _initialize function interface in module.py.

When use_gpu is true, it means that the GPU is used to start the service. - The configurable parameters in predict_args are consistent with the predict function interface in module.py.

Note: - When using the configuration file to start the service, other parameters will be ignored. - If you use GPU prediction (that is, use_gpu is set to true), you need to set the environment variable CUDA_VISIBLE_DEVICES before starting the service, such as:

```bash linenums="1"
export CUDA_VISIBLE_DEVICES=0
```

use_gpu and use_multiprocess cannot be true at the same time.

For example, use GPU card No. 3 to start the 2-stage series service:

export CUDA_VISIBLE_DEVICES=3
hub serving start -c deploy/hubserving/ocr_system/config.json

3. Send prediction requests¶

After the service starts, you can use the following command to send a prediction request to obtain the prediction result:

python tools/test_hubserving.py --server_url=server_url --image_dir=image_path

Two parameters need to be passed to the script:

server_url:service address, the format of which is http://[ip_address]:[port]/predict/[module_name]

For example, if using the configuration file to start the text angle classification, text detection, text recognition, detection+classification+recognition 3 stages, table recognition and PP-Structure service,

also modified the port for each service, then the server_url to send the request will be:

http://127.0.0.1:8865/predict/ocr_det
http://127.0.0.1:8866/predict/ocr_cls
http://127.0.0.1:8867/predict/ocr_rec
http://127.0.0.1:8868/predict/ocr_system
http://127.0.0.1:8869/predict/structure_table
http://127.0.0.1:8870/predict/structure_system
http://127.0.0.1:8870/predict/structure_layout
http://127.0.0.1:8871/predict/kie_ser
http://127.0.0.1:8872/predict/kie_ser_re

image_dir:Test image path, which can be a single image path or an image directory path
visualize:Whether to visualize the results, the default value is False
output:The folder to save the Visualization result, the default value is ./hubserving_result

Example:

python tools/test_hubserving.py --server_url=http://127.0.0.1:8868/predict/ocr_system --image_dir=./doc/imgs/ --visualize=false`

4. Returned result format¶

The returned result is a list. Each item in the list is a dictionary which may contain three fields. The information is as follows:

field name	data type	description
angle	str	angle
text	str	text content
confidence	float	text recognition confidence
text_region	list	text location coordinates
html	str	table HTML string
regions	list	The result of layout analysis + table recognition + OCR, each item is a list including `bbox` indicating area coordinates, `type` of area type and `res` of area results
layout	list	The result of layout analysis, each item is a dict, including `bbox` indicating area coordinates, `label` of area type

The fields returned by different modules are different. For example, the results returned by the text recognition service module do not contain text_region, detailed table is as follows:

field name/module name	ocr_det	ocr_cls	ocr_rec	ocr_system	structure_table	structure_system	structure_layout	kie_ser	kie_re
angle		✔		✔
text			✔	✔		✔		✔	✔
confidence		✔	✔	✔		✔		✔	✔
text_region	✔			✔		✔		✔	✔
html					✔	✔
regions					✔	✔
layout							✔
ser_res								✔
re_res									✔

Note: If you need to add, delete or modify the returned fields, you can modify the file module.py of the corresponding module. For the complete process, refer to the user-defined modification service module in the next section.

5. User-defined service module modification¶

If you need to modify the service logic, the following steps are generally required (take the modification of deploy/hubserving/ocr_system for example):

Stop service:

hub serving stop --port/-p XXXX

Modify the code in the corresponding files under deploy/hubserving/ocr_system, such as module.py and params.py, to your actual needs.

For example, if you need to replace the model used by the deployed service, you need to modify model path parameters det_model_dir and rec_model_dir in params.py. If you want to turn off the text direction classifier, set the parameter use_angle_cls to False.

Of course, other related parameters may need to be modified at the same time. Please modify and debug according to the actual situation.

It is suggested to run module.py directly for debugging after modification before starting the service test.

Note The image input shape used by the PPOCR-v3 recognition model is 3, 48, 320, so you need to modify cfg.rec_image_shape = "3, 48, 320" in params.py, if you do not use the PPOCR-v3 recognition model, then there is no need to modify this parameter. 3. (Optional) If you want to rename the module, the following lines should be modified: - ocr_system within from deploy.hubserving.ocr_system.params import read_params - ocr_system within name="ocr_system", 4. (Optional) It may require you to delete the directory __pycache__ to force flush build cache of CPython:

find deploy/hubserving/ocr_system -name '__pycache__' -exec rm -r {} \;

Install modified service module:

1	`hub install deploy/hubserving/ocr_system/`

Restart service:

hub serving start -m ocr_system