parameters: (contents, name=None)
docstring: r"""Convenience function to check if the 'contents' encodes a PNG image.
  
    Args:
      contents: 0-D `string`. The encoded image bytes.
      name: A name for the operation (optional)
  
    Returns:
       A scalar boolean tensor indicating if 'contents' may be a PNG image.
       is_png is susceptible to false positives.
docstring_summary: r"""Convenience function to check if the 'contents' encodes a PNG image.
docstring_tokens: r Convenience function to check if the contents encodes a PNG image .
function: def _is_png(contents, name=None):
    r"""Convenience function to check if the 'contents' encodes a PNG image.
  
    Args:
      contents: 0-D `string`. The encoded image bytes.
      name: A name for the operation (optional)
  
    Returns:
       A scalar boolean tensor indicating if 'contents' may be a PNG image.
       is_png is susceptible to false positives.
    """
    with ops.name_scope(name, 'is_png'):
      substr = string_ops.substr(contents, 0, 3)
      return math_ops.equal(substr, b'\211PN', name=name)
function_tokens: def _is_png ( contents , name = None ) : with ops . name_scope ( name , 'is_png' ) : substr = string_ops . substr ( contents , 0 , 3 ) return math_ops . equal ( substr , b'\211PN' , name = name )