Add border around selection

[kboehme1]

OS: MacOS
Version: ImageMagick 7.0.5-0 Q16 x86_64 2017-02-21 http://www.imagemagick.org

I have an image that is a black outline on transparent background.
https://www.dropbox.com/s/6t9r4m408ljre ... e.png?dl=0

I would like to select all black color and add a 2 pixel red border around it.

https://www.dropbox.com/s/65udncxwuqmsp ... e.png?dl=0

[fmw42]

Perhaps it would be best to upload your image to some free hosting service such as dropbox.com and put the URL here so we can fully understand your problem.

[kboehme1]

Perhaps it would be best to upload your image to some free hosting service such as dropbox.com and put the URL here so we can fully understand your problem.

Updated the question to include examples.

[fmw42]

try this:

Code: Select all

convert shape.png \
\( -clone -0 -background red -flatten \) \
\( -clone -0 -alpha extract -morphology dilate diamond:2 \) \
-delete 0 -alpha off -compose copy_opacity -composite \
-background black -alpha background result.png

[kboehme1]

That works great. Thanks!