OCR通用印刷体识别能识别pdf吗

我测试了一下通用印刷体识别，用图片可以识别成功，但是用PDF文件就报1102错误，不知道是什么原因，哪个大神解答下{"code":-1102,"message":"SDK_IMAGE_DECODE_FAILED","data":{"recognize_warn_msg":[],"recognize_warn_code":[],"items":[],"session_id":"1257423962-2026704825","class":[]}