Ruby Sinatra：在发送到API之前，通过MiniMagick压缩tempfile中的图像

在向API发送请求之前，我尝试使用以下代码压缩图像：

require 'sinatra'
require 'unirest'
require 'mini_magick'
require 'json'

require 'open-uri'

get '/' do

    File.read('public/views/index.erb')

end

post '/' do
    Unirest.timeout(5)
    image = MiniMagick::Image.open(params['user_image'][:tempfile])
    image.resize "600x400" 
    response = Unirest.post 'https://search.craftar.net/v1/search',
            parameters: {
                token: "703eb042371c49f0",
                image: image                                        
            }

    body = response.body

    url = body['results'][0]['item']['url']

  redirect url

end

当它运行以获得结果时，我得到以下错误：

ArgumentError at /
wrong number of arguments (1 for 0)

/usr/local/Cellar/ruby/2.2.3/lib/ruby/2.2.0/tempfile.rb in open
  def open
/usr/local/Cellar/ruby/2.2.3/lib/ruby/2.2.0/open-uri.rb in open
      name.open(*rest, &block)
/usr/local/lib/ruby/gems/2.2.0/gems/mini_magick-4.3.6/lib/mini_magick/image.rb in open
      Kernel.open(path_or_url, "rb") do |file|
server.rb in block in <main>
    image = MiniMagick::Image.open(params['user_image'][:tempfile])
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb in call
          proc { |a,p| unbound_method.bind(a).call }
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb in block in compile!
          proc { |a,p| unbound_method.bind(a).call }
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb in []
            route_eval { block[*args] }
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb in block (3 levels) in route!
            route_eval { block[*args] }
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb in route_eval
      throw :halt, yield
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb in block (2 levels) in route!
            route_eval { block[*args] }
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb in block in process_route
        block ? block[self, values] : yield(self, values)
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb in catch
      catch(:pass) do
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb in process_route
      catch(:pass) do
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb in block in route!
          returned_pass_block = process_route(pattern, keys, conditions) do |*args|
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb in each
        routes.each do |pattern, keys, conditions, block|
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb in route!
        routes.each do |pattern, keys, conditions, block|
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb in block in dispatch!
        route!
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb in block in invoke
      res = catch(:halt) { yield }
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb in catch
      res = catch(:halt) { yield }
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb in invoke
      res = catch(:halt) { yield }
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb in dispatch!
      invoke do
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb in block in call!
      invoke { dispatch! }
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb in block in invoke
      res = catch(:halt) { yield }
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb in catch
      res = catch(:halt) { yield }
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb in invoke
      res = catch(:halt) { yield }
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb in call!
      invoke { dispatch! }
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb in call
      dup.call!(env)
/usr/local/lib/ruby/gems/2.2.0/gems/rack-protection-1.5.3/lib/rack/protection/xss_header.rb in call
        status, headers, body = @app.call(env)
/usr/local/lib/ruby/gems/2.2.0/gems/rack-protection-1.5.3/lib/rack/protection/path_traversal.rb in call
        app.call env
/usr/local/lib/ruby/gems/2.2.0/gems/rack-protection-1.5.3/lib/rack/protection/json_csrf.rb in call
        status, headers, body = app.call(env)
/usr/local/lib/ruby/gems/2.2.0/gems/rack-protection-1.5.3/lib/rack/protection/base.rb in call
        result or app.call(env)
/usr/local/lib/ruby/gems/2.2.0/gems/rack-protection-1.5.3/lib/rack/protection/base.rb in call
        result or app.call(env)
/usr/local/lib/ruby/gems/2.2.0/gems/rack-protection-1.5.3/lib/rack/protection/frame_options.rb in call
        status, headers, body        = @app.call(env)
/usr/local/lib/ruby/gems/2.2.0/gems/rack-1.6.4/lib/rack/logger.rb in call
      @app.call(env)
/usr/local/lib/ruby/gems/2.2.0/gems/rack-1.6.4/lib/rack/commonlogger.rb in call
      status, header, body = @app.call(env)
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb in call
        call_without_check(env)
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb in call
      env['sinatra.commonlogger'] ? @app.call(env) : super
/usr/local/lib/ruby/gems/2.2.0/gems/rack-1.6.4/lib/rack/head.rb in call
    status, headers, body = @app.call(env)
/usr/local/lib/ruby/gems/2.2.0/gems/rack-1.6.4/lib/rack/methodoverride.rb in call
      @app.call(env)
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/show_exceptions.rb in call
      @app.call(env)
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb in call
      result, callback = app.call(env), env['async.callback']
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb in call
      @stack.call(env)
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb in block in call
        synchronize { prototype.call(env) }
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb in synchronize
          yield
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb in call
        synchronize { prototype.call(env) }
/usr/local/lib/ruby/gems/2.2.0/gems/rack-1.6.4/lib/rack/handler/webrick.rb in service
        status, headers, body = @app.call(env)
/usr/local/Cellar/ruby/2.2.3/lib/ruby/2.2.0/webrick/httpserver.rb in service
      si.service(req, res)
/usr/local/Cellar/ruby/2.2.3/lib/ruby/2.2.0/webrick/httpserver.rb in run
          server.service(req, res)
/usr/local/Cellar/ruby/2.2.3/lib/ruby/2.2.0/webrick/server.rb in block in start_thread
          block ? block.call(sock) : run(sock)

ArgumentError位于/
参数数目错误（1代表0）
/打开的usr/local/ceral/ruby/2.2.3/lib/ruby/2.2.0/tempfile.rb
def打开
/open中的usr/local/ceral/ruby/2.2.3/lib/ruby/2.2.0/open-uri.rb
name.open（*rest和block）
/打开的usr/local/lib/ruby/gems/2.2.0/gems/mini_-magick-4.3.6/lib/mini_-magick/image.rb
open（path_或url，“rb”）do|文件|
块中的server.rb
image=MiniMagick:：image.open（参数['user\u image'][：tempfile]）
/调用中的usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb
proc{a，p|unbound_method.bind（a.call}
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb在编译中的块中！
proc{a，p|unbound_method.bind（a.call}
/[]中的usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb
路由_eval{block[*args]}
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb块（3层）在路线中！
路由_eval{block[*args]}
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb在路线评估中
停止，屈服
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb块（2层）在路线中！
路由_eval{block[*args]}
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb位于流程中的块中
块块[self，values]：屈服（self，values）
/捕获中的usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb
接住做某事
/进程路径中的usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb
接住做某事
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb在路径中的块中！
返回的_pass_block=进程_路由（模式、键、条件）do |*args|
/每个文件中的usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb
路由。每个do |模式、键、条件、块|
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb正在运行中！
路由。每个do |模式、键、条件、块|
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb在发送中的块中！
路线！
/调用中块中的usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb
res=捕获（：暂停）{yield}
/捕获中的usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb
res=捕获（：暂停）{yield}
/调用中的usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb
res=捕获（：暂停）{yield}
/发送中的usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb！
调用do
/调用块中的usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb！
调用{dispatch！}
/调用中块中的usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb
res=捕获（：暂停）{yield}
/捕获中的usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb
res=捕获（：暂停）{yield}
/调用中的usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb
res=捕获（：暂停）{yield}
/usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb呼叫中！
调用{dispatch！}
/调用中的usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb
重复呼叫！（环境）
/调用中的usr/local/lib/ruby/gems/2.2.0/gems/rack-protection-1.5.3/lib/rack/protection/xss_header.rb
状态、标题、正文=@app.call（env）
/调用中的usr/local/lib/ruby/gems/2.2.0/gems/rack-protection-1.5.3/lib/rack/protection/path_traversal.rb
app.call env
/调用中的usr/local/lib/ruby/gems/2.2.0/gems/rack-protection-1.5.3/lib/rack/protection/json_csrf.rb
状态、标题、正文=app.call（env）
/调用中的usr/local/lib/ruby/gems/2.2.0/gems/rack-protection-1.5.3/lib/rack/protection/base.rb
结果或应用程序调用（环境）
/调用中的usr/local/lib/ruby/gems/2.2.0/gems/rack-protection-1.5.3/lib/rack/protection/base.rb
结果或应用程序调用（环境）
/调用中的usr/local/lib/ruby/gems/2.2.0/gems/rack-protection-1.5.3/lib/rack/protection/frame_options.rb
状态、标题、正文=@app.call（env）
/调用中的usr/local/lib/ruby/gems/2.2.0/gems/rack-1.6.4/lib/rack/logger.rb
@应用程序调用（环境）
/调用中的usr/local/lib/ruby/gems/2.2.0/gems/rack-1.6.4/lib/rack/commonlogger.rb
状态、标题、正文=@app.call（env）
/调用中的usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb
在不检查的情况下调用（env）
/调用中的usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb
环境['sinatra.commonlogger']@应用呼叫（环境）：超级
/调用中的usr/local/lib/ruby/gems/2.2.0/gems/rack-1.6.4/lib/rack/head.rb
状态、标题、正文=@app.call（env）
/调用中的usr/local/lib/ruby/gems/2.2.0/gems/rack-1.6.4/lib/rack/methodoverride.rb
@应用程序调用（环境）
/调用中的usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/show_exceptions.rb
@应用程序调用（环境）
/调用中的usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb
结果，callback=app.call（env），env['async.callback']
/调用中的usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb
@stack.call（env）
/调用块中的usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb
同步{prototype.call（env）}
/同步中的usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb
产量
/调用中的usr/local/lib/ruby/gems/2.2.0/gems/sinatra-1.4.6/lib/sinatra/base.rb
同步{prototype.call（env）}
/usr/local/lib/ruby/gems/2.2.0/gems/rack-1.6.4/lib/rack/handler/webrick.rb在服务中
状态、标题、正文=@app.call（env）
/usr/local/ceral/ruby/2.2.3/lib/ruby/2.2.0/webrick/httpserver.rb正在服务中
si.服务（需求、资源）
/usr/local/ceral/ruby/2.2.3/lib
image = MiniMagick::Image.open(File.new(params[:user_image][:tempfile]))