PngImagePlugin.py 文件源码

def chunk_zTXt(self, pos, length):

        # compressed text
        s = ImageFile._safe_read(self.fp, length)
        try:
            k, v = s.split(b"\0", 1)
        except ValueError:
            k = s
            v = b""
        if v:
            comp_method = i8(v[0])
        else:
            comp_method = 0
        if comp_method != 0:
            raise SyntaxError("Unknown compression method %s in zTXt chunk" %
                              comp_method)
        try:
            v = _safe_zlib_decompress(v[1:])
        except ValueError:
            if ImageFile.LOAD_TRUNCATED_IMAGES:
                v = b""
            else:
                raise
        except zlib.error:
            v = b""

        if k:
            if bytes is not str:
                k = k.decode('latin-1', 'strict')
                v = v.decode('latin-1', 'replace')

            self.im_info[k] = self.im_text[k] = v
            self.check_text_memory(len(v))

        return s