我没有对此进行测试,但您应该能够使用“convert_options”参数,如下所示:
:convert_options => { :all => ‘-colorspace Gray’ }
看一下https://github.com/thoughtbot/paperclip/blob/master/lib/paperclip/thumbnail.rb https://github.com/thoughtbot/paperclip/blob/master/lib/paperclip/thumbnail.rb
我个人使用我自己的处理器。
在模型中:
has_attached_file :logo,
:url => PaperclipAssetsController.config_url,
:path => PaperclipAssetsController.config_path,
:styles => {
:grayscale => { :processors => [:grayscale] }
}
In lib:
module Paperclip
# Handles grayscale conversion of images that are uploaded.
class Grayscale < Processor
def initialize file, options = {}, attachment = nil
super
@format = File.extname(@file.path)
@basename = File.basename(@file.path, @format)
end
def make
src = @file
dst = Tempfile.new([@basename, @format])
dst.binmode
begin
parameters = []
parameters << ":source"
parameters << "-colorspace Gray"
parameters << ":dest"
parameters = parameters.flatten.compact.join(" ").strip.squeeze(" ")
success = Paperclip.run("convert", parameters, :source => "#{File.expand_path(src.path)}[0]", :dest => File.expand_path(dst.path))
rescue PaperclipCommandLineError => e
raise PaperclipError, "There was an error during the grayscale conversion for #{@basename}" if @whiny
end
dst
end
end
end
对于简单的灰度转换来说,这可能不是 100% 必要的,但它确实有效!