From their documentation: https://github.com/blueimp/jQuery-File-Upload/wiki/API#programmatic-file-upload
$('#fileupload').fileupload('add', {files: filesList});
The second argument must be an object with an array (or array-like
list) of File or Blob objects as files property.
So sounds like it is as simple as:
var blob = ... //you said in the comments you've got the blob...
var blob = 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAYAAACNbyblAAAAHElEQVQI12P4//8/w38GIAXDIBKE0DHxgljNBAAO9TXL0Y4OHwAAAABJRU5ErkJggg==';
$('#fileupload').fileupload('add', {files: [blob]})
Now, I've also come across some more complex code (source) that suggests something like this is also possible:
$('#fileupload').fileupload({
autoUpload: true,
add: function (event, data) {
$.ajax({
url: "/upload",
type: 'POST',
dataType: 'json',
data: {doc: {title: data.files[0].name}},
async: false,
success: function(response) {
...
}
});
Seems pretty flexible.