imagemagick - RMagick 无法读取远程图像

Question

我的环境是 Linux centos，使用 ruby​​ 1.8.7，代码如下:

require 'rubygems'
require 'RMagick'
Magick::Image.read("http://image.domain.com/image.darenhui.com/images/random_bg/01.jpg")[0]

它抛出如下错误:

in `read': no decode delegate for this image format `//image.domain.com/images/random_bg/01.jpg' @ error/constitute.c/ReadImage/532 (Magick::ImageMagickError), 

但如果我从本地读到:

    require 'rubygems'
    require 'RMagick'
    Magick::Image.read("/local/staticimages/random_bg/01.jpg")[0]

一切都好。
我运行识别 -list 格式，见下文:

     JPEG* JPEG      rw-   Joint Photographic Experts Group JFIF format (62)
     JPG* JPEG      rw-   Joint Photographic Experts Group JFIF format (62)

但是当我通过身份测试“http://image.domain.com/image.darenhui.com/images/random_bg/01.jpg”失败，但“/local/staticimages/random_bg/01.jpg”成功

有人可以给我一些线索吗？先感谢您。

Answer 1

Magick::Image.read不支持 URL 链接。但是您可以使用 ruby​​ open 读取远程图像方法:

 require 'rubygems'
 require 'RMagick'
 require "open-uri"


image = Magick::ImageList.new  
urlimage = open("http://www.jewelinfo4u.com/images/Gallery/ruby.jpg") # Image Remote URL 
image.from_blob(urlimage.read)

# crop = image.crop(10,10,200,300) You can crop this image too
# crop.write('C:/nameofyourNewImage.jpg') If you want to save the image you can use this line in windows