我有一个模特：
class PropertyImage < ActiveRecord::Base
has_attached_file :picture,
storage: :s3,
s3_credentials: CONFIG['s3'],
s3_protocol: (Rails.env.development? ? "http": "https"),
styles: {
thumb: '100x100>',
large: '633x460>',
medium: '301x240>'
}
end
我使用Rails（4.0.1），可卡因（0.5.4）和回形针（3.5.4）。
我想迁移旧图像（没有拇指，大中型）并调整每个图像的大小，所以我创建了一个rake脚本：
namespace :migrate_images do
desc "Resize Images in PropertyImage"
task start_migration: :environment do
PropertyImage.not_migrated.find_each do |pi|
ImageConverter.perform(pi)
end
end
end
和ImageConverter类：
class ImageConverter
def self.perform(pi)
begin
pi.picture.reprocess!
pi.update_attributes!({migrated: true})
puts "PropertyImage [#{pi.id}] has been migrated."
rescue Exception => e
puts "PropertyImage [#{pi.id}] has an error. #{e}"
end
end
end
现在，当我运行脚本时，我不断收到以下错误：
⇒ bundle exec rake migrate_images:start_migration
[deprecated] I18n.enforce_available_locales will default to true in the future. If you really want to skip validation of your locale you can set I18n.enforce_available_locales = false to avoid this message.
PropertyImage [11] has an error. Validation failed: Picture Paperclip::Errors::NotIdentifiedByImageMagickError, Picture Paperclip::Errors::NotIdentifiedByImageMagickError, Picture Paperclip::Errors::NotIdentifiedByImageMagickError
PropertyImage [12] has an error. Validation failed: Picture Paperclip::Errors::NotIdentifiedByImageMagickError, Picture Paperclip::Errors::NotIdentifiedByImageMagickError, Picture Paperclip::Errors::NotIdentifiedByImageMagickError
请注意，我阅读了类似的文章，并将以下内容添加到application.rb：
的末尾Paperclip.options[:command_path] = "/usr/local/bin/identify"
我确保安装了imagemagick：
⇒ brew install imagemagick
Warning: You have an outdated version of /usr/bin/install_name_tool installed.
This will cause binary package installations to fail.
This can happen if you install osx-gcc-installer or RailsInstaller.
To restore it, you must reinstall OS X or restore the binary from
the OS packages.
Warning: imagemagick-6.8.9-7 already installed
任何帮助都将受到高度赞赏。
请注意，如果我尝试使用rails console重现问题：
>> p = Property.find(93746)
>> p.property_images.each do |pi|
?> pi.picture.reprocess!
>> end
PropertyImage Load (1.4ms) SELECT "property_images".* FROM "property_images" WHERE "property_images"."invalid_image" = 'f' AND "property_images"."property_id" = $1 ORDER BY "property_images"."apartment_main" DESC [["property_id", 93746]]
[paperclip] copying /property_images/pictures/000/325/476/original/722952f7-4cd4-47bb-bdcf-c7411c9d6021.jpg to local file /var/folders/g8/3v37gc0x16b313mvf7464qtc0000gn/T/dfe10026af3ac1b8cc5c94f00437092020141027-6352-12gmkmc.jpg
[AWS S3 200 1.212736 0 retries] get_object(:bucket_name=>"my_bucket_development",:key=>"property_images/pictures/000/325/476/original/722952f7-4cd4-47bb-bdcf-c7411c9d6021.jpg")
Command :: identify -format '%wx%h,%[exif:orientation]' '/var/folders/g8/3v37gc0x16b313mvf7464qtc0000gn/T/dfe10026af3ac1b8cc5c94f00437092020141027-6352-12gmkmc.jpg[0]' 2>/dev/null
[paperclip] An error was received while processing: #<Paperclip::Errors::NotIdentifiedByImageMagickError: Paperclip::Errors::NotIdentifiedByImageMagickError>
Command :: identify -format '%wx%h,%[exif:orientation]' '/var/folders/g8/3v37gc0x16b313mvf7464qtc0000gn/T/dfe10026af3ac1b8cc5c94f00437092020141027-6352-12gmkmc.jpg[0]' 2>/dev/null
[paperclip] An error was received while processing: #<Paperclip::Errors::NotIdentifiedByImageMagickError: Paperclip::Errors::NotIdentifiedByImageMagickError>
Command :: identify -format '%wx%h,%[exif:orientation]' '/var/folders/g8/3v37gc0x16b313mvf7464qtc0000gn/T/dfe10026af3ac1b8cc5c94f00437092020141027-6352-12gmkmc.jpg[0]' 2>/dev/null
[paperclip] An error was received while processing: #<Paperclip::Errors::NotIdentifiedByImageMagickError: Paperclip::Errors::NotIdentifiedByImageMagickError>
[paperclip] saving /property_images/pictures/000/325/476/original/722952f7-4cd4-47bb-bdcf-c7411c9d6021.jpg
[AWS S3 200 0.293473 0 retries] put_object(:acl=>:public_read,:bucket_name=>"my_bucket_development",:content_length=>0,:content_type=>"image/jpeg",:data=>Paperclip::AttachmentAdapter: 722952f7-4cd4-47bb-bdcf-c7411c9d6021.jpg,:key=>"property_images/pictures/000/325/476/original/722952f7-4cd4-47bb-bdcf-c7411c9d6021.jpg")
(0.2ms) BEGIN
(0.2ms) ROLLBACK
答案 0 :(得分：1)
确保您正在使用的服务器上的Imagemagick支持您尝试上传的格式。
要确保这一点，请使用以下命令：
convert -list format
如果您尝试使用Paperclip上传的格式不在列表中，则需要安装所需的库，然后重新安装/重新编译Imagemagick。
Here给出了一个如何在Unix机器上执行此操作的示例。要安装jpg库，请使用以下命令：
yum install libjpeg libjpeg-devel
如何安装库并重新安装/重新编译Imagemagick取决于您使用的操作系统以及您需要的图像格式。