update

Signed-off-by: junjie.jiang <junjie.jiang@zilliz.com>

image_decoder.py

@@ -40,11 +40,17 @@ class ImageDecoder(PyOperator):
     def __init__(self):
         self._nvjpeg = create_pynvjpeg()
 
-    def to_device(self, device):
-        if self._nvjpeg is not None:
-            if not self._nvjpeg.bind_device(device):
+    def to_device(self):
+        if self._nvjpeg is not None and self.device >= 0:
+            if not self._nvjpeg.bind_device(self.device):
                 self._nvjpeg = None
 
+    @property
+    def device(self):
+        if hasattr(self, '_device'):
+            return self._device
+        return -1
+
     def _download_image(self, image_url):
         image_type = image_url.split('?')[0].split('.')[-1].lower()
         is_jpeg = True if image_type == 'jpeg' or image_type == 'jpg' else False