White horizontal lines in the generated image

[hedeya1980]

I was trying to use the 'pca_color_augmentation_tensor' function, but I'm continuously getting white horizontal lines in the generated image. Could you pls advise the reason of this, and how this can be corrected?

[koshian2]

@hedeya1980
The reason why you get horizontal stripes is that the rank of the input tensor is different.

Rank 3 tensors are for time series data. If you feed rank 3 tensors(image) to PCA augmentation,

from PIL import Image
import matplotlib.pyplot as plt
def test():
    with Image.open("truck.png", "r") as img:
        X = np.asarray(img, np.uint8) / 255.0
        X_aug = pca_color_augmentation_tensor(X)
    plt.imshow(X_aug)
    plt.show()

But if you feed rank 4 tensors, horizontal stripes do not appear.

def test():
    with Image.open("truck.png", "r") as img:
        X = np.expand_dims(np.asarray(img, np.uint8) / 255.0, 0)
        X_aug = pca_color_augmentation_tensor(X)
    plt.imshow(X_aug[0])
    plt.show()

All you need to do is use np.expand_dims() and change the input tensor rank to 4.
Thanks for your report.