 the ResNet-50 model.
       </p>
       <p>
        From the
        <a class="reference external" href="https://arxiv.org/abs/1611.10012">
         Speed/accuracy trade-offs for modern convolutional object detectors
        </a>
        paper, the following enhancements were made to the backbone: * The conv5_x, avgpool, fc and softmax layers were removed from the original classification model. * All strides in conv4_x are set to 1x1.
       </p>
       <p>
        The backbone is followed by 5 additional 