def linear_norm(arr, highval=255):
    if arr.ndim == 3:
        min_, max_ = arr.min((0, 1)), arr.max((0, 1))
        for dim in range(arr.ndim):
            arr[:, :, dim] = (
                highval * (arr[:, :, dim] - min_[dim]) / (max_[dim] - min_[dim])
            )
    else:
        min_, max_ = arr.min(), arr.max()
        arr = highval * (arr - min_) / (max_ - min_)
    return arr


def binarize(arr, threshold=0, max_val=1):
    arr[arr > threshold] = max_val
    return arr