How to use dragonfly to crop a circular section from an image

[Praveenram Balachandar]

Hi,

I'm using dragonfly 0.9.15.

Given an image, I'm confused at how to use the convert method in dragonfly to crop a circular portion from the image with transparent background.

I am able to use a direct image magick command to run it from command line but the example command I found uses actual files and I'm unaware of how to get the file while dragonfly processes it on the fly.

Here's the actual command I took from a stack overflow post on imagemagick.

http://stackoverflow.com/a/999563/1664852

Command:

convert -size 200x200 xc:none -fill walter.jpg -draw "circle 100,100 100,1" circle_thumb.png




Now I tried to replicate the same with a convert in dragonfly.

require 'dragonfly/rails/images'

Dragonfly[:images].configure do |c|
  c.job :crop_circle do
    process :resize, "320x440"
    encode :png
    process :convert, '-virtual-pixel HorizontalTile -background transparent -draw "circle 400,400 400,1" -compose Copy_Opacity -composite'
  end
end




How can I achieve this.

Any help is appreciated. The output I want is exactly same as what is there on the stackoverflow post I've mentioned.

Thanks,

Praveen.

[Thomas Bindzus]

Hi Praveenram,

I've posed an answer to the question on Stackoverflow:

http://stackoverflow.com/questions/20477809/crop-circular-image-with-dragonfly-rails/25750740#25750740

You probably don't need it anymore, but perhaps someone else will find it useful :-)

Kind regards

- Thomas