garbage collect expired Blobs

src/jp4-canvas/jquery-jp4.js

@@ -425,8 +425,12 @@
                 ctx.drawImage(this,0,0,cnv_w,cnv_h);
 
                 decode_and_display(ctx);
+
             }
 
+            //delete this.src;
+            URL.revokeObjectURL(this.src);
+
         };
         //obj.blob = window.URL.createObjectURL(http.response);
         //process_image(obj.blob);