[julia-users] Re: Displaying an array of images in an IJulia notebook

[Steven G. Johnson]

The text/plain hack you implemented is definitely wrong, and will cause 
problems if the writemime function is used in any other context.

You need to decide what MIME type the vector of images will be.   The most 
natural choices would be either HTML 
(http://stackoverflow.com/questions/2807251/can-i-embed-a-png-image-into-an-html-page)
 
or SVG 
(http://stackoverflow.com/questions/6249664/does-svg-support-embedding-of-bitmap-images),
 
both of which support embedding PNG data.

e.g. for HTML, you could do something like the following (untested, may 
have typos):

function Base.writemime(io::IO, ::MIME"text/html", x::AbstractVector{Png})
    print(io, "<p>", length(x), "-element ", typeof(x), "<ul>)
    png = MIME("image/png")
    for i in x
        print(io, "<li><img src=\"data:image/png;base64,", 
base64(writemime, png, i), "\" /></li>")
    end
    print(io, "</ul>")
end