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Hello Reshape SSD Sample

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Hello Reshape SSD Sample

.. meta:: :description: Learn how to do inference of object detection models using shape inference feature and Synchronous Inference Request API (Python, C++).

This sample demonstrates how to do synchronous inference of object detection models using :doc:Shape Inference feature <../../../openvino-workflow/running-inference/model-input-output/changing-input-shape>. Before using the sample, refer to the following requirements:

  • Models with only one input and output are supported.
  • The sample accepts any file format supported by core.read_model.
  • The sample has been validated with the person-detection-retail-0013 model and the NCHW layout format.
  • To build the sample, use instructions available at :ref:Build the Sample Applications <build-samples> section in "Get Started with Samples" guide.

How It Works ####################

At startup, the sample application reads command-line parameters, prepares input data, loads a specified model and image to the OpenVINO™ Runtime plugin, performs synchronous inference, and processes output data. As a result, the program creates an output image, logging each step in a standard output stream.

.. tab-set::

.. tab-item:: Python :sync: python

  .. scrollbox::

     .. doxygensnippet:: samples/python/hello_reshape_ssd/hello_reshape_ssd.py
        :language: python

.. tab-item:: C++ :sync: cpp

  .. scrollbox::

     .. doxygensnippet:: samples/cpp/hello_reshape_ssd/main.cpp
        :language: cpp

You can see the explicit description of each sample step at :doc:Integration Steps <../../../openvino-workflow/running-inference> section of "Integrate OpenVINO™ Runtime with Your Application" guide.

Running ####################

.. tab-set::

.. tab-item:: Python :sync: python

  .. code-block:: console

     python hello_reshape_ssd.py <path_to_model> <path_to_image> <device_name>

.. tab-item:: C++ :sync: cpp

  .. code-block:: console

     hello_reshape_ssd <path_to_model> <path_to_image> <device_name>

To run the sample, you need to specify a model and an image:

  • You can get a model specific for your inference task from one of model repositories, such as TensorFlow Zoo, HuggingFace, or TensorFlow Hub.
  • You can use images from the media files collection available at the storage <https://storage.openvinotoolkit.org/data/test_data>__.

.. note::

  • By default, OpenVINO™ Toolkit Samples and demos expect input with BGR channels order. If you trained your model to work with RGB order, you need to manually rearrange the default channels order in the sample or demo application or reconvert your model using model conversion API with reverse_input_channels argument specified. For more information about the argument, refer to the Color Conversion section of :doc:Preprocessing API <../../../openvino-workflow/running-inference/optimize-inference/optimize-preprocessing/preprocessing-api-details>.
  • Before running the sample with a trained model, make sure the model is converted to the intermediate representation (IR) format (*.xml + *.bin) using :doc:model conversion API <../../../openvino-workflow/model-preparation/convert-model-to-ir>.
  • The sample accepts models in ONNX format (.onnx) that do not require preprocessing.

Example ++++++++++++++++++++

  1. Download a pre-trained model:

  2. You can convert it by using:

    .. tab-set::

    .. tab-item:: Python :sync: python

      .. code-block:: python
    
         import openvino as ov
    
         ov_model = ov.convert_model('./test_data/models/mobilenet-ssd')
         # or, when model is a Python model object
         ov_model = ov.convert_model(mobilenet-ssd)
    

    .. tab-item:: CLI :sync: cli

      .. code-block:: console
    
         ovc ./test_data/models/mobilenet-ssd
    
  3. Perform inference of an image, using a model on a GPU, for example:

    .. tab-set::

    .. tab-item:: Python :sync: python

      .. code-block:: console
    
         python hello_reshape_ssd.py ./test_data/models/mobilenet-ssd.xml banana.jpg GPU
    

    .. tab-item:: C++ :sync: cpp

      .. code-block:: console
    
         hello_reshape_ssd ./models/person-detection-retail-0013.xml person_detection.bmp GPU
    

Sample Output ####################

.. tab-set::

.. tab-item:: Python :sync: python

  The sample application logs each step in a standard output stream and
  creates an output image, drawing bounding boxes for inference results
  with an over 50% confidence.

  .. code-block:: console

     [ INFO ] Creating OpenVINO Runtime Core
     [ INFO ] Reading the model: C:/test_data/models/mobilenet-ssd.xml
     [ INFO ] Reshaping the model to the height and width of the input image
     [ INFO ] Loading the model to the plugin
     [ INFO ] Starting inference in synchronous mode
     [ INFO ] Found: class_id = 52, confidence = 0.98, coords = (21, 98), (276, 210)
     [ INFO ] Image out.bmp was created!
     [ INFO ] This sample is an API example, for any performance measurements please use the dedicated benchmark_app tool

.. tab-item:: C++ :sync: cpp

  The application renders an image with detected objects enclosed in rectangles.
  It outputs the list of classes of the detected objects along with the
  respective confidence values and the coordinates of the rectangles to the
  standard output stream.

  .. code-block:: console

     [ INFO ] OpenVINO Runtime version ......... <version>
     [ INFO ] Build ........... <build>
     [ INFO ]
     [ INFO ] Loading model files: \models\person-detection-retail-0013.xml
     [ INFO ] model name: ResMobNet_v4 (LReLU) with single SSD head
     [ INFO ]     inputs
     [ INFO ]         input name: data
     [ INFO ]         input type: f32
     [ INFO ]         input shape: {1, 3, 320, 544}
     [ INFO ]     outputs
     [ INFO ]         output name: detection_out
     [ INFO ]         output type: f32
     [ INFO ]         output shape: {1, 1, 200, 7}
     Reshape network to the image size = [960x1699]
     [ INFO ] model name: ResMobNet_v4 (LReLU) with single SSD head
     [ INFO ]     inputs
     [ INFO ]         input name: data
     [ INFO ]         input type: f32
     [ INFO ]         input shape: {1, 3, 960, 1699}
     [ INFO ]     outputs
     [ INFO ]         output name: detection_out
     [ INFO ]         output type: f32
     [ INFO ]         output shape: {1, 1, 200, 7}
     [0,1] element, prob = 0.716309,    (852,187)-(983,520)
     The resulting image was saved in the file: hello_reshape_ssd_output.bmp

     This sample is an API example, for any performance measurements please use the dedicated benchmark_app tool

Additional Resources ####################

  • :doc:Integrate the OpenVINO™ Runtime with Your Application <../../../openvino-workflow/running-inference>
  • :doc:Get Started with Samples <get-started-demos>
  • :doc:Using OpenVINO Samples <../openvino-samples>
  • :doc:Convert a Model <../../../openvino-workflow/model-preparation/convert-model-to-ir>
  • Hello Reshape SSD Python Sample on Github <https://github.com/openvinotoolkit/openvino/blob/master/samples/python/hello_reshape_ssd/README.md>__
  • Hello Reshape SSD C++ Sample on Github <https://github.com/openvinotoolkit/openvino/blob/master/samples/cpp/hello_reshape_ssd/README.md>__