win7 下 使用命令 gem install rtesseract 是如下错误

Building native extensions. This could take a while... ERROR: Error installing rtesseract: ERROR: Failed to build gem native extension.

C:/Ruby186/bin/ruby.exe extconf.rb checking for Ruby version >= 1.8.5... yes 无效驱动器规格。 Unable to get ImageMagick version *** extconf.rb failed *** Could not create Makefile due to some reason, probably lack of necessary libraries and/or headers. Check the mkmf.log file for more details. You may need configuration options.

如果使用本地安装命令

G:>gem install rtesseract-0.0.13.gem -l ERROR: Error installing rtesseract-0.0.13.gem: rtesseract requires rmagick (>= 2.10.1, runtime)

是这个错误 求大牛指导下该怎么安装