MiniMagick: make a square

Question

I do this:

begin
  image = MiniMagick::Image.open(params[:avatar_file].path)
  unless image.valid?
    raise nil
  end
rescue
  return head :not_acceptable
end
image.format 'jpeg'
image.resize '128x128'
image.write dir.to_s + current_user.id.to_s + '_128x128.jpg'

And after the resizing, if an image wasn't a square, one of the sides has 128 pixels and the second is smaller than the first.

I would like to make them the same size by cropping the center of the image.

As far as I know, "convert" utility of ImageMagick has "gravity center", but I'm not sure that this is what I need and how to use it with MiniMagick.

Answer 1

The answer is in the image.combine_options block:

begin
  image = MiniMagick::Image.open(params[:avatar_file].path)
  unless image.valid?
    raise nil
  end
rescue
  return head :not_acceptable
end
image.format 'jpeg'
image.combine_options do |c|
  c.resize '128x128^'
  c.gravity 'center'
  c.extent '128x128'
end
image.write dir.to_s + current_user.id.to_s + '_128x128.jpg'

ImageMagick variant:

convert stock.jpg -resize 128x128^ -gravity center -extent 128x128 result.jpg