Hands-On Convolutional Neural Networks with TensorFlow

Creating training set for Yolo object detection

To create the training set for YOLO, a grid of the same size as output feature map prediction from the YOLO network is placed on each training input image. For each cell within the grid, we create a target vector Y of length B*5+C (that is, the same as output feature map grid cell size in the preceding section).

Let's take an example training image and see how we create target vector for cells in grid on the image:

In the preceding illustration, consider that we choose the cell based on the shortest distance of the object center (in the image, the back car's center is closest to the green cell).  ...