Update README.md

Author: JingShing

README.md

@@ -10,6 +10,6 @@ You can get this exe on itch.io : https://jingshing.itch.io/pixel-art-filter
 ![OR OR](https://github.com/JingShing/Pixel-Art-transform-in-python/blob/main/sample/or.jpg)
 
 ## Effect
-![1 1](https://github.com/JingShing/Pixel-Art-transform-in-python/blob/main/sample/1.jpg)
-![2 2](https://github.com/JingShing/Pixel-Art-transform-in-python/blob/main/sample/2.jpg)
-![3 3](https://github.com/JingShing/Pixel-Art-transform-in-python/blob/main/sample/3.jpg)
+![1 1](https://github.com/JingShing/Pixel-Art-transform-in-python/blob/main/sample/1.png)
+![2 2](https://github.com/JingShing/Pixel-Art-transform-in-python/blob/main/sample/2.png)
+![3 3](https://github.com/JingShing/Pixel-Art-transform-in-python/blob/main/sample/3.png)