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MindOCR Offline Inference

Introduction

MindOCR inference supports Ascend310/Ascend310P devices, supports MindSpore Lite inference backend, integrates text detection, angle classification, and text recognition, implements end-to-end OCR inference process, and optimizes inference performance using pipeline parallelism.

MindOCR supported models can find in MindOCR models listPPOCR models list, You can jump to the models list page to download MindIR/ONNX for converting MindSpore Lite offline models.

The overall process of MindOCR Lite inference is as follows:

graph LR;
    A[MindOCR models] -- export --> B[MindIR] -- converter_lite --> C[MindSpore Lite MindIR];
    D[ThirdParty models] -- xx2onnx --> E[ONNX] -- converter_lite --> C;
    C --input --> F[MindOCR Infer] -- outputs --> G[Evaluation];
    H[images] --input --> F[MindOCR Infer];

Environment Instalation

Please refer to Offline Inference Environment Installation.

Model conversion

Please refer to Model Converter Tutorial.

Inference (Python)

Enter the inference directory:cd deploy/py_infer.

Detection + Classification + Recognition

python infer.py \
    --input_images_dir=/path/to/images \
    --det_model_path=/path/to/mindir/dbnet_resnet50.mindir \
    --det_model_name_or_config=../../configs/det/dbnet/db_r50_icdar15.yaml \
    --cls_model_path=/path/to/mindir/cls_mv3.mindir \
    --cls_model_name_or_config=ch_pp_mobile_cls_v2.0 \
    --rec_model_path=/path/to/mindir/crnn_resnet34.mindir \
    --rec_model_name_or_config=../../configs/rec/crnn/crnn_resnet34.yaml \
    --res_save_dir=det_cls_rec \
    --vis_pipeline_save_dir=det_cls_rec

Note: set --character_dict_path=/path/to/xxx_dict.txt if not only use numbers and lowercase.

The visualization images are stored in det_cls_rec, as shown in the picture.

Visualization of text detection and recognition result

The results are saved in det_cls_rec/pipeline_results.txt in the following format:

img_182.jpg [{"transcription": "cocoa", "points": [[14.0, 284.0], [222.0, 274.0], [225.0, 325.0], [17.0, 335.0]]}, {...}]

Detection + Recognition

If you don't enter the parameters related to classification, it will skip and only perform detection+recognition.

python infer.py \
    --input_images_dir=/path/to/images \
    --det_model_path=/path/to/mindir/dbnet_resnet50.mindir \
    --det_model_name_or_config=../../configs/det/dbnet/db_r50_icdar15.yaml \
    --rec_model_path=/path/to/mindir/crnn_resnet34.mindir \
    --rec_model_name_or_config=../../configs/rec/crnn/crnn_resnet34.yaml \
    --res_save_dir=det_rec \
    --vis_pipeline_save_dir=det_rec

Note: set --character_dict_path=/path/to/xxx_dict.txt if not only use numbers and lowercase.

The visualization images are stored in det_rec folder, as shown in the picture.

Visualization of text detection and recognition result

The recognition results are saved in det_rec/pipeline_results.txt in the following format:

img_498.jpg [{"transcription": "keep", "points": [[819.0, 71.0], [888.0, 67.0], [891.0, 104.0], [822.0, 108.0]]}, {...}]

Detection

Run text detection alone.

python infer.py \
    --input_images_dir=/path/to/images \
    --det_model_path=/path/to/mindir/dbnet_resnet50.mindir \
    --det_model_name_or_config=../../configs/det/dbnet/db_r50_icdar15.yaml \
    --res_save_dir=det \
    --vis_det_save_dir=det

The visualization results are stored in the det folder, as shown in the picture.

Visualization of text detection result

The detection results are saved in the det/det_results.txt file in the following format:

img_108.jpg [[[226.0, 442.0], [402.0, 416.0], [404.0, 433.0], [228.0, 459.0]], [...]]

Classification

Run text angle classification alone.

# cls_mv3.mindir is converted from ppocr
python infer.py \
    --input_images_dir=/path/to/images \
    --cls_model_path=/path/to/mindir/cls_mv3.mindir \
    --cls_model_name_or_config=ch_pp_mobile_cls_v2.0 \
    --res_save_dir=cls

The results will be saved in cls/cls_results.txt, with the following format:

word_867.png   ["180", 0.5176]
word_1679.png  ["180", 0.6226]
word_1189.png  ["0", 0.9360]

Recognition

Run text recognition alone.

python infer.py \
    --input_images_dir=/path/to/images \
    --backend=lite \
    --rec_model_path=/path/to/mindir/crnn_resnet34.mindir \
    --rec_model_name_or_config=../../configs/rec/crnn/crnn_resnet34.yaml \
    --res_save_dir=rec

Note: set --character_dict_path=/path/to/xxx_dict.txt if not only use numbers and lowercase.

The results will be saved in rec/rec_results.txt, with the following format:

word_421.png   "under"
word_1657.png  "candy"
word_1814.png  "cathay"

Detail of inference parameter

Details
  • Basic settings
name type default description
input_images_dir str None Image or folder path for inference
device str Ascend Device type, support Ascend
device_id int 0 Device id
backend str lite Inference backend, support lite
parallel_num int 1 Number of parallel in each stage of pipeline parallelism
precision_mode str None Precision mode, only supports setting by Model Conversion currently, and it takes no effect here
  • Saving Result
name type default description
res_save_dir str inference_results Saving dir for inference results
vis_det_save_dir str None Saving dir for images of with detection boxes
vis_pipeline_save_dir str None Saving dir for images of with detection boxes and text
vis_font_path str None Font path for drawing text
crop_save_dir str None Saving path for cropped images after detection
show_log bool False Whether show log when inferring
save_log_dir str None Log saving dir
  • Text detection
name type default description
det_model_path str None Model path for text detection
det_model_name_or_config str None Model name or YAML config file path for text detection
  • Text angle classification
name type default description
cls_model_path str None Model path for text angle classification
cls_model_name_or_config str None Model name or YAML config file path for text angle classification
  • Text recognition
name type default description
rec_model_path str None Model path for text recognition
rec_model_name_or_config str None Model name or YAML config file path for text recognition
character_dict_path str None Dict file for text recognition,default only supports numbers and lowercase

Notes:

*_model_name_or_config can be the model name or YAML config file path, please refer to MindOCR models listPPOCR models list.

Model Inference Evaluation

Text detection

After inference, please use the following command to evaluate the results:

python deploy/eval_utils/eval_det.py \
    --gt_path=/path/to/det_gt.txt \
    --pred_path=/path/to/prediction/det_results.txt

Text recognition

After inference, please use the following command to evaluate the results:

python deploy/eval_utils/eval_rec.py \
    --gt_path=/path/to/rec_gt.txt \
    --pred_path=/path/to/prediction/rec_results.txt \
    --character_dict_path=/path/to/xxx_dict.txt

Please note that character_dict_path is an optional parameter, and the default dictionary only supports numbers and English lowercase.

When evaluating the PaddleOCR series models, please refer to Third-party Model Support List to use the corresponding dictionary.