Revert "added the possibility to use the -alpha option from imagemagick, and added tests for it"

This reverts commit 0cf31d5.

Author: rubikan

lib/grim.rb

@@ -17,9 +17,6 @@ module Grim
   # Default colorspace
   COLORSPACE = "RGB"
 
-  # Default alpha
-  ALPHA = "Set"
-
   # Default exception class for Grim.
   class Exception < ::StandardError
   end

lib/grim/image_magick_processor.rb

@@ -21,12 +21,11 @@ def count(path)
     end
 
     def save(pdf, index, path, options)
-      alpha = options.fetch(:alpha, Grim::ALPHA)
       width   = options.fetch(:width,   Grim::WIDTH)
       density = options.fetch(:density, Grim::DENSITY)
       quality = options.fetch(:quality, Grim::QUALITY)
       colorspace = options.fetch(:colorspace, Grim::COLORSPACE)
-      command = [@imagemagick_path, "-resize", width.to_s, "-alpha", alpha, "-antialias", "-render",
+      command = [@imagemagick_path, "-resize", width.to_s, "-antialias", "-render",
         "-quality", quality.to_s, "-colorspace", colorspace,
         "-interlace", "none", "-density", density.to_s,
         "#{Shellwords.shellescape(pdf.path)}[#{index}]", path]

spec/fixtures/remove_alpha.pdf

@@ -95,22 +95,6 @@
     end
   end
 
-  describe "#save with alpha option" do
-    before(:each) do
-      @path1 = tmp_path("to_png_spec-1.png")
-      @path2 = tmp_path("to_png_spec-2.png")
-      @pdf  = Grim::Pdf.new(fixture_path("remove_alpha.pdf"))
-    end
-
-    it "should use alpha" do
-      Grim::ImageMagickProcessor.new.save(@pdf, 0, @path1, {:alpha => 'Set'})
-      Grim::ImageMagickProcessor.new.save(@pdf, 0, @path2, {:alpha => 'Remove'})
-
-      `convert #{@path1} -verbose info:`.include?("alpha: 8-bit").should be_true
-      `convert #{@path2} -verbose info:`.include?("alpha: 1-bit").should be_true
-    end
-  end
-
   describe "#save with colorspace option" do
     before(:each) do
       @path1 = tmp_path("to_png_spec-1.jpg")

spec/lib/grim/image_magick_processor_spec.rb

@@ -26,10 +26,6 @@
     Grim::COLORSPACE.should == 'RGB'
   end
 
-  it "should have ALPHA constant set to 'Set'" do
-    Grim::ALPHA.should == 'Set'
-  end
-
   describe "#reap" do
     it "should return an instance of Grim::Pdf" do
       Grim.reap(fixture_path("smoker.pdf")).class.should == Grim::Pdf