Opportunity to add an image from url and comp in Blog description and Custom Pages

[khet]

1. I want to change function “insert image” in Blog Settings->Edit Title and Description. Users can add image only from url in blog description now. How I can change this function for users opportunity to add an image from url and comp?
2. The same problem in Blog Settings -> Edit Custom Pages. I need opportunity to add an image from url and comp. How I can add attachments function in this menu as well?

Thank you in in advance