diff --git a/cista/preview.py b/cista/preview.py
index dbb2893..fed9c8e 100644
--- a/cista/preview.py
+++ b/cista/preview.py
@@ -108,11 +108,13 @@ def process_video(path, *, maxsize, quality):
         img = frame.to_image()
         del frame, stream
 
-    img.thumbnail((maxsize, maxsize))
-    imgdata = io.BytesIO()
-    if rotation:
-        img = img.rotate(rotation, expand=True)
-    img.save(imgdata, format="webp", quality=quality, method=4)
+        img.thumbnail((maxsize, maxsize))
+        imgdata = io.BytesIO()
+        if rotation:
+            img = img.rotate(rotation, expand=True)
+        img.save(imgdata, format="webp", quality=quality, method=4)
+        del img
+
     ret = imgdata.getvalue()
     gc.collect()
     return ret