CODEWITHSUNDEEP
ruby-on-railsimage-processingupload
user142019
user142019

Reputation:

Basic image resizing in Ruby on Rails

I'm creating a little photo sharing site for our home's intranet, and I have an upload feature, which uploads the photo at original size into the database. However, I also want to save the photo in four other sizes: W=1024, W=512, W=256 and W=128, but only the sizes smaller than the original size (e.g. if the original width is 511, only generate 256 and 128). The image with a width of 128 should always be generated (because it's a thumbnail). Also, the resization should always be with a proportional width and height. How can I implement this? I already have this code to upload the photo:

pic.rb <-- model

def image_file=(input_data)
  self.filename     = input_data.original_filename
  self.content_type = input_data.content_type.chomp
  self.binary_data  = input_data.read
  # here it should generate the smaller sizes
  #+and save them to self.binary_data_1024, etc...
end

new.rb <-- view

<h1>New pic</h1>

<% form_for(@pic, :html => {:multipart => true}) do |f| %>
  <%= f.error_messages %>

  <p>
    <%= f.label :title %><br />
    <%= f.text_field :title %>
  </p>
  <p>
    <%= f.label :description %><br />
    <%= f.text_field :description %>
  </p>
  <p>
    <%= f.label :image_file %><br />
    <%= f.file_field :image_file %>
  </p>
  <p>
    <%= f.submit 'Create' %>
  </p>
<% end %>

<%= link_to 'Back', pics_path %>

Thanks

Upvotes: 14

Views: 37635

Answers (5)

Sebtm
Sebtm

Reputation: 7164

You can resize with RMagick gem.

This is just a example that you can adapt:

require 'RMagick'

f = File.new( File.join(save_path, self.filename), "wb"  )
f.write form_file.read #remeber to set :html=>{:multipart => true} in form
f.close

image = Magick::Image.read(self.filename).first
image.change_geometry!("640x480") { |cols, rows, img|
    newimg = img.resize(cols, rows)
    newimg.write("newfilename.jpg")
}

More Info here: http://www.imagemagick.org/script/api.php#ruby

Upvotes: 27

Vaibhav Maheshwari
Vaibhav Maheshwari

Reputation: 391

There is a gem called "Refile". It is great. Go ahead and check this tutorial on how to use it. https://gorails.com/episodes/file-uploads-with-refile here is how to do it.

Add this to your gem file 

gem 'refile', '~> 0.4.2', require: ["refile/rails", "refile/image_processing"]

Create a table field using rails migration in your table as image_id of string type.Now comes how to insert into that field and display the image.

Use this in your upload form, largely form_for do |f| 

 <%= f.attachment_field :image %>

if you are using rails 4 make sure you pass rails strong parameters.

Put this in your model.rb file where you are storing the image (below class modelname)

attachment :image

displaying the image is simple.

<%= image_tag attachment_url(current_user,:image, :fill, 200, 170, format: "jpg") %>

Upvotes: 1

suresh gopal
suresh gopal

Reputation: 3156

I tried following way. Its working fine. I hope it will help to some one.

1.add following gem in Gemfile:

gem "ImageResize", "~> 0.0.5"

2.run bundle

3.use this in controller function:

require 'rubygems'
require 'ImageResize'

#input_image_filename, output_image_filename, max_width, max_height
Image.resize('big.jpg', 'small.jpg', 40, 40)

Upvotes: 3

kernification
kernification

Reputation: 523

Knowing this is an old one, but here is a very nice railscast according to this topic: http://railscasts.com/episodes/253-carrierwave-file-uploads It is using rmagic and carrierwave.

Upvotes: 2

denisjacquemin
denisjacquemin

Reputation: 7414

Simply use paperclip or attachment_fu

Upvotes: 10

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