'IHDR chunk in PNG image'

@property
def IHDR(self):

    match = (lambda chunk: (chunk.type_name == PNG_CHUNK_TYPE.IHDR))
    IHDR = self._find_first(match)
    if (IHDR is None):
        raise InvalidImageStreamError('no    IHDR    chunk    in    PNG    image')
    return IHDR
