Issue using mini_magick to process images with CarrierWave gem in Rails app

Question

I'm on Windows 8.1. After a good 5 hours, I finally set up CarrierWave in my rails app. I had to install ImageMagick (running convert -version returns "Version: ImageMagick 6.9.8-4 Q16 x64 2017-04-25", so I know it's installed). Uploading files works as expected and all is fine.

The next step was to include mini_magick so I can resize and make thumbnail versions of images, and so I uncommented the following lines from my image_uploader.rb file:

  include CarrierWave::MiniMagick

   version :thumb do
     process :resize_to_fit => [200, 100]
   end

I then added mini_magick to my gemfile and can confirm it's there (running bundle install returns "Using mini_magick 4.7.0"). But now, whenever I upload a file, I receive the following error:

• Images Failed to manipulate with MiniMagick, maybe it is not an image? Original Error: ImageMagick/GraphicsMagick is not installed

Now I know it is an image, as it worked with the same files before I tried manipulating using MiniMagick. ImageMagick is definitely installed. I can't find a single reference on SO to my problem. What am I doing wrong?

Thank you in advance.

edit: running convert -version lists the delegates (built in) as follows:

Delegates (built-in): bzlib cairo flif freetype jng jp2 jpeg lcms lqr openexr pa ngocairo png ps rsvg tiff webp xml zlib

And I don't see jpg on that list. But even attempting to upload a .png file, I receive the same error.

Answer 1

After a couple of days of not doing anything, I restarted this guide from the beginning. When I got to the stage of image processing for different sizes, I uncommented the following code from my uploader.rb and added the require statement that was casually mentioned in the guide (and I skipped over the first time).

include CarrierWave::MiniMagick
require 'carrierwave/processing/mini_magick'
version :thumb do
 process :resize_to_fit => [600, 450]
end

Running bundle install and continuing the rest of the tutorial worked and images are resized as desired now.