From 9a78e379364e7c31cf4810c3e302090087efb900 Mon Sep 17 00:00:00 2001
From: Dov Grobgeld <dov.grobgeld@gmail.com>
Date: Mon, 7 Feb 2022 15:24:36 +0200
Subject: [PATCH] Add support for 1-bit images to ImageOps.invert()

---
 src/PIL/ImageOps.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/PIL/ImageOps.py b/src/PIL/ImageOps.py
index b170e9d8c..b513776a4 100644
--- a/src/PIL/ImageOps.py
+++ b/src/PIL/ImageOps.py
@@ -520,6 +520,11 @@ def invert(image):
     :param image: The image to invert.
     :return: An image.
     """
+    # Special case for 1-bit images using python translate() method
+    if image.mode == '1':
+        lut = bytearray(range(255,-1,-1))
+        return Image.frombuffer('1',image.size,image.tobytes().translate(lut))
+    
     lut = []
     for i in range(256):
         lut.append(255 - i)