FEATURE: new 'convert_pasted_images_to_hq_jpg' site setting

app/controllers/uploads_controller.rb

@@ -70,6 +70,15 @@ class UploadsController < ApplicationController
 
       return { errors: I18n.t("upload.file_missing") } if tempfile.nil?
 
+      # convert pasted images to HQ jpegs
+      if filename == "blob.png" && SiteSetting.convert_pasted_images_to_hq_jpg
+        filename = "blob.jpg"
+        jpeg_path = "#{File.dirname(tempfile.path)}/#{filename}"
+        content_type = "image/jpeg"
+        `convert #{tempfile.path} -quality 95 #{jpeg_path}`
+        tempfile = File.open(jpeg_path)
+      end
+
       # allow users to upload large images that will be automatically reduced to allowed size
       max_image_size_kb = SiteSetting.max_image_size_kb.kilobytes
       if max_image_size_kb > 0 && FileHelper.is_image?(filename)

config/locales/server.en.yml

@@ -1069,6 +1069,8 @@ en:
 
     allow_all_attachments_for_group_messages: "Allow all email attachments for group messages."
 
+    convert_pasted_images_to_hq_jpg: "Convert pasted images to high-quality JPG files."
+
     enable_flash_video_onebox: "Enable embedding of swf and flv (Adobe Flash) links in oneboxes. WARNING: may introduce security risks."
 
     default_invitee_trust_level: "Default trust level (0-4) for invited users."

config/site_settings.yml

@@ -717,6 +717,7 @@ files:
     shadowed_by_global: true
   default_opengraph_image_url: ''
   allow_all_attachments_for_group_messages: false
+  convert_pasted_images_to_hq_jpg: true
 
 trust:
   default_trust_level: