The 2D registration results are dark

[LexTran]

Describe the bug Hi, I was using ANTsPy to register 2D images, but I got 2 dark image as warped result and inverse warped result, I don't understand what's going on.

To Reproduce My code to register the images is as follow:

def img_to_single_component(name):
    img = Image.open(name)
    # img = img.resize((1080, 1080))
    img = img.convert('P')
    img1 = ants.from_numpy(np.array(img))
    return img1
def antsRegistration(fi_path, mv_path, method, random_seed):
    fi = img_to_single_component(fi_path)
    mi = img_to_single_component(mv_path)
    mytx = ants.registration(fixed=fi, moving=mi, type_of_transform=method, randome_seed=random_seed)
    my_warped_image = ants.apply_transforms(fixed=fi, moving=mi, transformlist=mytx['fwdtransforms'],interpolator='nearestNeighbor')
    my_inversed_warped_image = ants.apply_transforms(fixed=mi, moving=fi, transformlist=mytx['invtransforms'],interpolator='nearestNeighbor')
    imageio.imwrite(f'{method}_Warped.png', my_warped_image.numpy())
    imageio.imwrite(f'{method}_InverseWarped.png', my_inversed_warped_image.numpy())

Expected behavior A clear and concise description of what you expected to happen.

Screenshots This is the warped image I get, the method is "Affine" and the interpolation is set to be "nearestNeighbor"

Desktop (please complete the following information):

• OS: Windows 10 Pro 64