update canvas for mask

canvas.svg

@@ -20,13 +20,13 @@
    xmlns:dc="http://purl.org/dc/elements/1.1/">
    <style>
    </style>
-   <defs id="defs2">
+   <defs id="filter_defs">
       <filter
          xmlns="http://www.w3.org/2000/svg"
          style="color-interpolation-filters:sRGB;"
          inkscape:label="Blur"
          xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
-         id="filter156128"
+         id="mask_rect_filter"
          x="-0.2" y="-0.2"
          width="1.5"
          height="1.5">
@@ -40,12 +40,12 @@
          maskUnits="userSpaceOnUse"
          id="tilefademask">
       <rect
-         id="rect156378"
+         id="mask_rect"
          width="640"
          height="512"
          x="-180"
          y="-25"
-         style="fill:#ffffff;filter:url(#filter156128)"
+         style="fill:#ffffff;filter:url(#mask_rect_filter)"
          transform="matrix(0.77703373,0,0,0.74018882,207.24036,100.70559)" />
       </mask>