merge images from Raphael svg

Question

Trying to create
Step 1 - Let users upload images through Ajax, Raphael and Raphael freetransform.

Step 2 - Click button to show one image from merge upload images. (Question): I have found similar post about convert Raphael svg 1 2 3,
so I'm using Canvg too but get console.log: Resource interpreted as image but transferred with MIME type text/html error: image "" not found.

Please help me find how to solve it. or any clue how to reach same goal(convert several Raphael svg images from upload to one png/jpeg) in other way?

Thanks!

Step 1

// upload images and ajax show in page
var paper = Raphael($('.upload_img')[0], 400, 200);
$('.upload_btn').click(function(){
    ...
    $.ajax({
        type: "POST",
        url: "index.php",
        data: fd,
        processData: false,
        contentType: false,
        success: function(html){
            var session = ..., file = ... type = ...; 
            function register(el) {
                // toggle handle
            };
            var img = new Image();
            img.onload = function(){
                var r_img = paper.image('img/product/tmp/'+session+'/'+file+type, 0, 0, 200, 200);
                register(r_img);
            };
            img.src = 'img/product/tmp/'+session+'/'+file+type;
        }
    });
});

Step 2

// merge and show
$('.merge_btn').click(function(){
    var upload_svg = $('.upload_img').html();
    canvg('canvas', upload_svg);
    console.log('upload_svg'+upload_svg); //<svg height="200" version="1.1" width="400" xmlns="http://www.w3.org/2000/svg" style="overflow-x: hidden; overflow-y: hidden; position: relative; "><desc></desc><defs></defs><image x="0" y="0" width="200" height="216.91973969631235" preserveAspectRatio="none" href="img/product/tmp/bc4d26ceb620852db36074d351883539/6.jpeg"></image></svg>
    // and get error
});


// These code If toggle show Raphael freetransform svg handle, it is work convert several svg handle to one image. but still not found upload image to merge

Answer 1

If I'm not mistaking canvg function expects the second parameter to be a String containing the path to your image file. However in step 2 your code does:

    var upload_svg = $('.upload_img').html(); // **** this does not return the image path
    canvg('canvas', upload_svg);

I suggest you try something like:

    var upload_svg = $('.upload_img').attr('src');
    canvg('canvas', upload_svg);

That will explain the error - Resource interpreted as image but transferred with MIME type text/html - it expects an image but receives blank HTML. The rest of the code seems fine.