Try before installing & automation of example-comparison.png

.gitattributes

@@ -0,0 +1 @@
+*.jpg diff=image

README.md

@@ -32,7 +32,7 @@ $ diff-image anImageThatHasChanged1.jpg anImageThatHasChanged2.jpg
 # The same as above, only using files on disk not git differences.
 ```
 
-![Screenshot](example-comparison.png?raw=true)
+![Screenshot](./images/example-comparison.png?raw=true)
 
 
 Installation
@@ -91,6 +91,17 @@ It will tell you what it's done, so it should look something like this:
 + git config --global diff.image.command '~/git-diff-image/git_diff_image'
 ```
 
+Try without installation
+------------------------
+
+```
+git config diff.image.command $(realpath diff-image)
+cd images
+make earth_with_label.jpg
+cp earth_with_label.jpg earth.jpg
+git diff earth.jpg
+```
+
 Git LFS
 -------
 

images/Makefile

@@ -0,0 +1,8 @@
+earth.jpg:
+	curl https://www.nasa.gov/wp-content/uploads/2023/03/135918main_bm1_high.jpg -o $@
+
+example-comparison.png: earth.jpg earth_with_label.jpg
+	../diff-image -o $@   $^
+
+earth_with_label.jpg: earth.jpg
+	convert $^ -gravity South -pointsize 60  -undercolor white -stroke gray -fill gray -annotate +30+30 'The earth seen from Apollo 17' $@