Fixes: TheAlgorithms#2404. Fix PIL DeprecationWarnings in pytest output (TheAlgorithms#2678)

Author: Dmytro Litvinov

Diff for: digital_image_processing/change_contrast.py

@@ -11,18 +11,18 @@
 from PIL import Image
 
 
-def change_contrast(img: Image, level: float) -> Image:
+def change_contrast(img: Image, level: int) -> Image:
     """
     Function to change contrast
     """
     factor = (259 * (level + 255)) / (255 * (259 - level))
 
-    def contrast(c: int) -> float:
+    def contrast(c: int) -> int:
         """
         Fundamental Transformation/Operation that'll be performed on
         every bit.
         """
-        return 128 + factor * (c - 128)
+        return int(128 + factor * (c - 128))
 
     return img.point(contrast)