FIGURE 2.

The training samples (deep images) generated through compressing the point cloud within the ROI (region of interest). The field of ROI is 1.028 m × 1.028 m and depth is determined by the depth of each training maize. The ROI covered an individual maize sample segmented manually, whose color is white with a red bounding box. Meanwhile, the target stem of the maize is in green with a green bounding box. Each sample was viewed from 32 different directions, which obtained 32 deep images with different background information. These deep images were used to train the deep convolutional neural network.