Is there an easy way to automatic vertical/horizontal align images with paperclip?

Question

I always want square images of 100x100 but i dont want to scale.

If the it is an image of 100X80 i want it vertical aligned with 10 white pixels on top and 10 white pixels on bottm.

Is there an easy way to handle this?

Using Rails 2.1 with paperclip 2.3.0

Answer 1

Ok i finally managed it.

i used this script to crop the image the way i want.

http://www.fmwconcepts.com/imagemagick/squareup/index.php

I made a new Paperclip processor and named CropFile. I copy pasted the Thumbnail processor from paper clip and added some lines to run the squareup script.

in my model:

has_attached_file :widget_image, :styles => { :square_60 => ["60x60", :png], :square_100 => ["100x100", :png] }, :processors => [:crop_file]

I added paperclip_postprocess.rb in initializers

#paperclip_postprocess.rb
module Paperclip
  # Handles thumbnailing images that are uploaded.
  class CropFile < Processor

    attr_accessor :current_geometry, :target_geometry, :format, :whiny, :convert_options, :source_file_options

    # Creates a Thumbnail object set to work on the +file+ given. It
    # will attempt to transform the image into one defined by +target_geometry+
    # which is a "WxH"-style string. +format+ will be inferred from the +file+
    # unless specified. Thumbnail creation will raise no errors unless
    # +whiny+ is true (which it is, by default. If +convert_options+ is
    # set, the options will be appended to the convert command upon image conversion
    def initialize file, options = {}, attachment = nil
      super

      geometry             = options[:geometry]
      @file                = file
      @crop                = geometry[-1,1] == '#'
      @target_geometry     = Geometry.parse geometry
      @current_geometry    = Geometry.from_file @file
      @source_file_options = options[:source_file_options]
      @convert_options     = options[:convert_options]
      @whiny               = options[:whiny].nil? ? true : options[:whiny]
      @format              = options[:format]
      @path                = options[:path]
      @source_file_options = @source_file_options.split(/\s+/) if @source_file_options.respond_to?(:split)
      @convert_options     = @convert_options.split(/\s+/)     if @convert_options.respond_to?(:split)

      @current_format      = File.extname(@file.path)
      @basename            = File.basename(@file.path, @current_format)
      # reg exp to get the with and the height
      geometry.match(/(\d+)(#|>|<)?x/)
      @width = $1
      @height = $3
    end

    # Returns true if the +target_geometry+ is meant to crop.
    def crop?
      @crop
    end

    # Returns true if the image is meant to make use of additional convert options.
    def convert_options?
      !@convert_options.nil? && !@convert_options.empty?
    end

    # Performs the conversion of the +file+ into a thumbnail. Returns the Tempfile
    # that contains the new image.
    def make
      src = @file

      dst = Tempfile.new(['bla', ".png"])
      dst.binmode

      begin
        parameters = []
        parameters << source_file_options
        parameters << ":source"
        parameters << transformation_command
        parameters << convert_options
        parameters << ":dest"

        parameters = parameters.flatten.compact.join(" ").strip.squeeze(" ")

        Paperclip.run("convert", parameters, :source => "#{File.expand_path(src.path)}[0]", :dest => File.expand_path(dst.path))
        # Cropping it with vertical and horizontal aligning
        `#{Rails.root}/public/scripts/squareup.sh -c trans -s #{@width} #{File.expand_path(src.path)} #{File.expand_path(dst.path)}`
      rescue PaperclipCommandLineError => e
        raise PaperclipError, "There was an error processing the thumbnail for #{@basename}" if @whiny
      end

      dst
    end

    # Returns the command ImageMagick's +convert+ needs to transform the image
    # into the thumbnail.
    def transformation_command
      scale, crop = @current_geometry.transformation_to(@target_geometry, crop?)
      trans = []
      trans << "-resize" << %["#{scale}"] unless scale.nil? || scale.empty?
      trans << "-crop" << %["#{crop}"] << "+repage" if crop
      trans
    end
  end
end

I added the following line to crop the images after paperclip has converted them

# Cropping it with vertical and horizontal aligning
`#{Rails.root}/public/scripts/squareup.sh -c trans -s #{@width} #{File.expand_path(src.path)} #{File.expand_path(dst.path)}`

If somebody gets a better idea, please give it to me :)

Thanks

Answer 2

Might not be appropriate, however you can use CSS to easily acchieve this:

html:
<div class="paperclip-holder">
   <%= your_paperclip_image_tag %>
</div>

css:
.paperclip-holder{
  width: 100px;
  height: 100px;
  background: #ffffff;
  vertical-align: center;
  text-align: center;
}