code: def DQT(self, marker):
      #
      # Define quantization table.  Support baseline 8-bit tables
      # only.  Note that there might be more than one table in
      # each marker.
  
      # FIXME: The quantization tables can be used to estimate the
      # compression quality.
  
      n = i16(self.fp.read(2)) - 2
      s = ImageFile._safe_read(self.fp, n)
      while len(s):
          if len(s) < 65:
              raise SyntaxError("bad quantization table marker")
          v = i8(s[0])
          if v // 16 == 0:
              self.quantization[v & 15] = array.array("B", s[1:65])
              s = s[65:]
          else:
              return
  
imports: from __future__ import print_function
  import array
  import io
  import struct
  import warnings
  from .None import Image, ImageFile, TiffImagePlugin
  from ._binary import i8, i16be, i32be, o8
  from ._util import isStringType
  from .JpegPresets import presets
label_desc: Use image node_id 5 for calling a global function with example usage: DQT(marker) without return types