Originally Posted by Old Pedant
Yes, that's exactly what I was implying: He's trying to improperly "rip" content.
i highly doubt that, SOP would prevent any outside image data from making it to the blob url shown by OP, but more-over he said "I click on a button, then choose a file on my PC". don't be accusatory. remember the lessons of Sodom and Gomorrah and try to be hospitable to strangers...
OP: you don't need to obtain the blob window.URL to upload, the blob object itself is fine.
You can either simply xhrt.send(blob), use the FormData virtual file builder and upload that, or use FileReader.readAsDataURL(blob) to grab the base64 data i alluded to before. each has a different server routine for catching the data, but it sounds like you havn't gotten to the server yet. at any rate, you have many options before you.
you might want to check out https://developer.mozilla.org/en-US/...ploading_files
BROWSER STATS [% share]
(2013/10/31) IE7:0.5, IE8:8.6, IE9:5.3, IE10:12.3, FF:17.7, CH:41.8, SF:8.1, MOBILE:20.4