resizing images in rails?


    how to resize the images in rails app?     i want 400X300 size images to display in my app.But if user enter 600X800 how to resize the image without effect on clarity?

  now i am using this code

     image ="#{RAILS_ROOT}/public/gallery/#{review_img}").first      selected_image = image.crop_resized(400,400)      selected_image.write("#{RAILS_ROOT}/public/gallery/#{review_img}")

   But it extract height and width.i dont want to extract only resize the image.    any suggestion are appreciated.

thanks, ravi.

==model (using attachment_fu)

class Picture < ActiveRecord::Base   belongs_to :user

  has_attachment :content_type => :image,                  :processor => 'image_science',                  :storage => :file_system,                  :path_prefix => File.join('public', 'images', 'pictures', ''),                  :resize_to => '400',                  :thumbnails => { :thumb => [150, 203]}

  validates_as_attachment end

will resize the image when created.