There are two types of zebra which accounts for the difficulty you mention. It can only be resolved from a photo if you revert using B&W. Border Collies exhibit the same difficulty. The ones South of Hadrian's Wall(English) are white dogs with areas of black and those North of the Wall( Scottish) are the reverse.

Yes I know that Hadrian's Wall no longer demarcates the border but no-one told the collies.

However for a colour photo of a B&W zebra I have to say this is very good