Is it a bad idea to upload image by POST JSON with DataURL?

What I mean is I convert the image to DataURL and make a JSON like

[{id: 1, dataurl: 'data:image/jpeg;base64,asdf***'}, {id: 2, dataurl: 'data:image/jpeg;base64,fsdfas***'}]

and post it to server.

Will it be different from uploading image by Form(multipart)?