Validate Image Colorspace With Paperclip

Question

I'm using Paperclip to convert images. I have noticed a severe degradation of quality of the produced image if its colorspace isn't set to srgb.

Is there a way to validate the colorspace of the uploaded image?

Answer 1

Ive got half an answer that might help...

You will need to install: https://github.com/rmagick/rmagick

Add to your model:

attr_accessor :image_colorspace
validates_exclusion_of :image_colorspace, in: [Magick::CMYKColorspace], message: 'is not RGB'
before_logo_post_process :read_image_colorspace
def read_image_colorspace
  self.image_colorspace = Magick::Image.from_blob(image.queued_for_write[:original].read).first.colorspace
  true
end

(Replace image with your attachment name.)

...or, if you prefer to not use rmagick, and you have a 'nix system, you could do this:

attr_accessor :image_colorspace
validates_exclusion_of :image_colorspace, in: ['CMYK'], message: 'is not RGB'
before_logo_post_process :read_image_colorspace
def read_image_colorspace
  self.logo_colorspace = `identify -verbose %m "#{image.queued_for_write[:original].path}" | grep 'Colorspace'`.to_s.upcase.strip.split(' ').last
  true
end