Upload images to Imgur from Mathematica

Question

Here\'s a challenge to all mathematica tag followers. Let\'s make it a lot more convenient to insert images into SO post from Mathematica by creating an imgur

Answer 1

Note: This is using the anonymous imgur uploader with my anonymous key. The imgur site restricts uploads to 50 uploads/hour which should be fine normally, but this may cause a problem if a lot of people try this simultaneously. So please get your own anonymous key here:

http://imgur.com/register/api_anon

And then replace the key in the code below with your own key (thanks!).

The trickiest part to code was the conversion from a Mathematica expression to PNG image to Base64 encoding to URL encoding. There are about a 1,000 ways to do it wrong and I think I managed to try them all.

The code breaks down into a few pieces:

• Construct the POST url
• Make the HTTP connection
• Send the POST url
• Read back the result, which is XML
• Extract the imgur url from the XML
• Format the imgur url as markdown (or as a Mathematica Hyperlink function).

Here is the code:

imgur[expr_] :=
 Module[{url, key, image, data, jUrl, jConn, jWriter, jInput, buffer,
   byte, xml, imgurUrl},
  Needs["JLink`"];
  JLink`JavaBlock[
   JLink`LoadJavaClass["java.net.URLEncoder"];
   url = "http://api.imgur.com/2/upload";
   key = "c07bc3fb59ef878d5e23a0c4972fbb29";
   image = ExportString[ExportString[expr, "PNG"], "Base64"];
   data =
    URLEncoder`encode["key"   , "UTF-8"] <> "=" <>
    URLEncoder`encode[ key    , "UTF-8"] <> "&" <>
    URLEncoder`encode["image" , "UTF-8"] <> "=" <>
    URLEncoder`encode[ image  , "UTF-8"] ;
   jUrl = JLink`JavaNew["java.net.URL", url];
   jConn = jUrl@openConnection[];
   jConn@setDoOutput[True];
   jWriter =
    JLink`JavaNew["java.io.OutputStreamWriter",
     jConn@getOutputStream[]];
   jWriter@write[data];
   jWriter@flush[];
   jInput = jConn@getInputStream[];
   buffer = {};
   While[(byte = jInput@read[]; byte >= 0), AppendTo[buffer, byte]];
   ];
  xml = ImportString[FromCharacterCode[buffer], "XML"];
  imgurUrl =
   Cases[xml,
     XMLElement["original", {}, {string_}] :>
      string, \[Infinity]][[1]];
  "![Mathematica graphic](" <> imgurUrl <> ")"
  ]

Testing:

In[]:= g = Graphics[{Blue, Disk[]}, PlotRange -> 1.2, ImageSize -> Small];
       pic = Overlay[{Blur[Binarize@g, 10], g}];
       imgur[pic]

Out[]= ![Mathematica graphic](http://i.imgur.com/eGOlL.png)

And the actual image: