回形针将图像保存为jpg与白色背景

Question

我想知道如何将带有alpha通道的png和gif文件转换为带有paperclip的白色背景的jpg

我试过这个但是,它不起作用

has_attached_file( 
  :photo, 
  :whiny => false, 
  :styles => { 
    :medium => ["300x300>", :jpg], 
    :thumb => ["100x100>", :jpg] 
  }, 
  :convert_options => { :all => '-alpha white -background white'}
)

它以灰色背景保存文件.

Answer 1

这里的解决方案

has_attached_file :photo,
  :styles => {
    :medium => ["300x300>",:jpg],
    :thumb => ["100x100>", :jpg]
  },
  :convert_options => {
    :all => '-background white -flatten +matte'
  }

Answer 2

-alpha remove -background white是优选的.white不是一个有效的论据-alpha.