Use Case and High-level Description

This is a MobileNetV2 + SSD-based vehicle and (Chinese) license plate detector for the "Barrier" use case.

Example

Specification

Metric	Value
Mean Average Precision (mAP)	99.52%
AP vehicles	99.90%
AP plates	99.13%
Car pose	Front facing cars
Min plate width	96 pixels
Max objects to detect	200
GFlops	0.271
MParams	0.547
Source framework	TensorFlow*

Average Precision (AP) is defined as an area under the precision/recall curve. Validation dataset is BIT-Vehicle.

Input

Original Model

An input image, name: input , shape: [1x256x256x3], format: [BxHxWxC], where:

B - batch size
H - image height
W - image width
C - number of channels

Expected color order: RGB. Mean values: [127.5,127.5,127.5], scale factor for each channel: 127.5

Converted Model

An input image, name: input, shape: [1x3x256x256], format [BxCxHxW], where:

B - batch size
C - number of channels
H - image height
W - image width

Expected color order is BGR.

Output

Original Model

The net outputs a blob with the shape: [1, 1, N, 7], where N is the number of detected bounding boxes. For each detection, the description has the format: [image_id, label, conf, x_min, y_min, x_max, y_max]

image_id - ID of the image in the batch
label - predicted class ID
conf - confidence for the predicted class
(x_min, y_min) - coordinates of the top left bounding box corner
(x_max, y_max) - coordinates of the bottom right bounding box corner.

Converted Model

The net outputs a blob with the shape: [1, 1, N, 7], where N is the number of detected bounding boxes. For each detection, the description has the format: [image_id, label, conf, x_min, y_min, x_max, y_max]

image_id - ID of the image in the batch
label - predicted class ID
conf - confidence for the predicted class
(x_min, y_min) - coordinates of the top left bounding box corner
(x_max, y_max) - coordinates of the bottom right bounding box corner.

Download a Model and Convert it into Inference Engine Format

You can download models and if necessary convert them into Inference Engine format using the Model Downloader and other automation tools as shown in the examples below.

An example of using the Model Downloader:

python3 <omz_dir>/tools/downloader/downloader.py --name <model_name>

An example of using the Model Converter:

python3 <omz_dir>/tools/downloader/converter.py --name <model_name>

Legal Information

The original model is distributed under the Apache License, Version 2.0. A copy of the license is provided in APACHE-2.0.txt.

[*] Other names and brands may be claimed as the property of others.