requires https://gist.github.com/NWPlayer123/eaa124d45b8ad31b83ebbc26be55c629

extract_wibn.py

from struct import unpack
from extract_nut import *

def full(f):
    return unpack(">I", f.read(4))[0]

with open("Banner.US.bin", "rb") as f:
    assert f.read(4) == b"WIBN"
    f.seek(0, 2)
    if f.tell() == 0xF0A0: #0xF0C0?
        num_icons = 8
    else:
        num_icons = 1
    f.seek(0x20)
    print(f.read(0x40).decode("UTF-16-BE").rstrip("\x00"))
    print(f.read(0x40).decode("UTF-16-BE").rstrip("\x00"))
    color = ColorConversion()
    tex = RGB5A3_Texture(64, 192, color)
    tex.DecodeImage(f)
    tex.image.save("banner.png")
    for i in range(num_icons):
        tex = RGB5A3_Texture(48, 48, color)
        tex.DecodeImage(f)
        tex.image.save("icon%d.png" % i)