Merge pull request #68 from driehuis/master

Add option to strip EXIF profiles

README.md

@@ -52,6 +52,11 @@ responsive_image:
   # working with JPGs directly from digital cameras and smartphones
   auto_rotate: false
 
+  # [Optional, Default: false]
+  # Strip EXIF and other JPEG profiles. Helps to minimize JPEG size and win friends
+  # at Google PageSpeed.
+  strip: false
+
   # [Optional, Default: assets]
   # The base directory where assets are stored. This is used to determine the
   # `dirname` value in `output_path_format` below.

features/image-generation.feature

@@ -86,3 +86,34 @@ Feature: Responsive image generation
     When I run Jekyll
     Then the file "_site/assets/resized/exif-rotation-100x50.jpeg" should exist
     Then the file "_site/assets/resized/progressive-100x50.jpeg" should exist
+
+  Scenario: Images should not be stripped of EXIF info by default
+    Given I have a responsive_image configuration with:
+      """
+        template: _includes/responsive-image.html
+        sizes:
+          - width: 100
+      """
+    And I have a file "index.html" with:
+      """
+        {% responsive_image path: assets/exif-rotation.jpeg %}
+      """
+    When I run Jekyll
+    Then the file "_site/assets/resized/exif-rotation-100x50.jpeg" should exist
+    Then the image "_site/assets/resized/exif-rotation-100x50.jpeg" should have an EXIF orientation
+
+  Scenario: Images can be stripped of EXIF info
+    Given I have a responsive_image configuration with:
+      """
+        template: _includes/responsive-image.html
+        sizes:
+          - width: 100
+        strip: true
+      """
+    And I have a file "index.html" with:
+      """
+        {% responsive_image path: assets/exif-rotation.jpeg %}
+      """
+    When I run Jekyll
+    Then the file "_site/assets/resized/exif-rotation-100x50.jpeg" should exist
+    Then the image "_site/assets/resized/exif-rotation-100x50.jpeg" should have no EXIF orientation

features/step_definitions/jekyll_steps.rb

@@ -65,6 +65,18 @@ Then /^the image "(.+)" should be interlaced$/ do |path|
   img.destroy!
 end
 
+Then /^the image "(.+)" should have an EXIF orientation$/ do |path|
+  img = Magick::Image::read(path).first
+  assert_not_equal img.orientation.to_i, 0
+  img.destroy!
+end
+
+Then /^the image "(.+)" should have no EXIF orientation$/ do |path|
+  img = Magick::Image::read(path).first
+  assert_equal img.orientation.to_i, 0
+  img.destroy!
+end
+
 def write_file(path, contents)
   File.open(path, 'w') do |f|
     f.write(contents)

lib/jekyll-responsive-image/config.rb

@@ -9,7 +9,8 @@ module Jekyll
         'extra_images'       => [],
         'auto_rotate'        => false,
         'save_to_source'     => true,
-        'cache'              => false
+        'cache'              => false,
+        'strip'              => false
       }
 
       def initialize(site)

lib/jekyll-responsive-image/resize_handler.rb

@@ -36,6 +36,9 @@ module Jekyll
 
           Jekyll.logger.info "Generating #{target_filepath}"
 
+          if config['strip']
+            img.strip!
+          end
           i = img.scale(ratio)
           i.write(target_filepath) do |f|
             f.interlace = i.interlace