text-spotting-0005 (composite)

Use Case and High-Level Description

This is a text spotting composite model that simultaneously detects and recognizes text. The model detects symbol sequences separated by space and performs recognition without a dictionary. The model is built on top of the Mask-RCNN framework with additional attention-based text recognition head.

Alphabet is alphanumeric: abcdefghijklmnopqrstuvwxyz0123456789.

Example

Composite model specification

Metric

Value

Word spotting hmean ICDAR2015, without a dictionary

71.29%

Source framework

PyTorch*

Hmean Word spotting is defined and measured according to the Incidental Scene Text (ICDAR2015) challenge.

Detector model specification

The text-spotting-0005-detector model is a Mask-RCNN-based text detector with ResNet50 backbone and additional text features output.

Metric

Value

GFlops

184.495

MParams

27.010

Inputs

Image, name: image, shape: 1, 3, 768, 1280 in the 1, C, H, W format, where:

  • C - number of channels

  • H - image height

  • W - image width

The expected channel order is BGR.

Outputs

Model has outputs with dynamic shapes.

  1. Name: labels, shape: -1. Contiguous integer class ID for every detected object, 0 is for text class.

  2. Name: boxes, shape: -1, 5. Bounding boxes around every detected object in the (top_left_x, top_left_y, bottom_right_x, bottom_right_y, confidence) format.

  3. Name: masks, shape: -1, 28, 28. Text segmentation masks for every output bounding box.

  4. Name: text_features, shape -1, 64, 28, 28. Text features that are fed to a text recognition head.

Encoder model specification

The text-spotting-0005-recognizer-encoder model is a fully-convolutional encoder of text recognition head.

Metric

Value

GFlops

2.082

MParams

1.328

Inputs

Name: input, shape: 1, 64, 28, 28. Text recognition features obtained from detection part.

Outputs

Name: output, shape: 1, 256, 28, 28. Encoded text recognition features.

Decoder model specification

Metric

Value

GFlops

0.106

MParams

0.283

Inputs

  1. Name: encoder_outputs, shape: 1, (28*28), 256. Encoded text recognition features.

  2. Name: prev_symbol, shape: 1. Index in alphabet of previously generated symbol.

  3. Name: prev_hidden, shape: 1, 1, 256. Previous hidden state of GRU.

Outputs

  1. Name: output, shape: 1, 38. Encoded text recognition features. Indices starting from 2 correspond to symbols from the alphabet. The 0 and 1 are special Start of Sequence and End of Sequence symbols correspondingly.

  2. Name: hidden, shape: 1, 1, 256. Current hidden state of GRU.

Training Pipeline

The OpenVINO Training Extensions provide a training pipeline, allowing to fine-tune the model on custom dataset.

Demo usage

The model can be used in the following demos provided by the Open Model Zoo to show its capabilities: