Thank you very much, very helpful!
@marcelbuechel
I understand your request for JuiceboxBuilder to accept images with filenames that contain special characters but the image filenames become part of URLs when they are uploaded to a web server and it would be wise to use only web-safe characters in filenames for this reason. Please see section 2.3 of this document for details.
Characters that are allowed in a URI but do not have a reserved purpose are called unreserved. These include uppercase and lowercase letters, decimal digits, hyphen, period, underscore, and tilde.
JuiceboxBuilder currently handles all images whose filenames use any or all of these characters.