A Novel Deep Convolutional Neural Network Based on ResNet-18 and Transfer Learning for Detection of Wood Knot Defects

Figure 2

Seven common wood knots and data augmentation of the dataset. Original images and those created through data augmentation: ① original image, ② vertical mirror, ③ rotated by 180, ④ horizontal mirror, ⑤ added Gaussian noise to image, ⑥ increased the hue by 10, and ⑦ added salt-and-pepper noise to image.

(a) Decayed knot

(b) Dry knot

(c) Edge knot

(d) Encased knot

(e) Horn knot

(f) Leaf knot

(g) Sound knot