Function blur

ldm/modules/image_degradation/bsrgan.py:128–142

x: image, NxcxHxW k: kernel, Nx1xhxw

(x, k)

def blur(x, k):
    '''
    x: image, NxcxHxW
    k: kernel, Nx1xhxw
    '''
    n, c = x.shape[:2]
    p1, p2 = (k.shape[-2] - 1) // 2, (k.shape[-1] - 1) // 2
    x = torch.nn.functional.pad(x, pad=(p1, p2, p1, p2), mode='replicate')
    k = k.repeat(1, c, 1, 1)
    k = k.view(-1, 1, k.shape[2], k.shape[3])
    x = x.view(1, -1, x.shape[2], x.shape[3])
    x = torch.nn.functional.conv2d(x, k, bias=None, stride=1, padding=0, groups=n * c)
    x = x.view(n, c, x.shape[2], x.shape[3])

    return x


def gen_kernel(k_size=np.array([15, 15]), scale_factor=np.array([4, 4]), min_var=0.6, max_var=10., noise_level=0):