use LANCZOS downsampling filter

app.py

@@ -68,7 +68,7 @@ class BZHStableSignatureDemo(object):
         if downscale != 1:
             size = img.size
             size = (int(size[0] / downscale), int(size[1] / downscale))
-            img = img.resize(size, Image.BICUBIC)
+            img = img.resize(size, Image.Resampling.LANCZOS)
         if crop != 0:
             width, height = img.size
             area = width * height