html - Image elements in an SVG don't appear when the SVG is used in a page.

Question

I've created an SVG image which layers together and animates several conventional PNG images. If I look at the image directly in a browser, things appear as they should (mostly, anyway - looks like there's a blending issue in FireFox, but that's a problem for another thread). But when I use the image in a page - either in an img tag or in the background of an element, none of the image elements within the SVG appear.

If I stick a regular shape into the SVG, it shows up, so I know the SVG is generally working, but the images within it never show up. Anyone know what I'm doing wrong?

Here's the SVG in text form for ease of reference:

<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" height="190" width="640">

<style type="text/css" >
  <![CDATA[

    .lighten{
        mix-blend-mode:lighten;
    }

    .layer{

    }

  ]]>
</style>

<!-- <rect width="640" height="190" fill="#9da99e" /> -->
<image class="layer lighten" width="640" height="190" xlink:href="http://omnichron.net/external/op/src/meridian/rays-bottom.png">
    <animateTransform attributeName="transform" attributeType="XML" type="rotate" from="0 320 95" to="360 320 95" dur="79s" repeatCount="indefinite" />
    <animate attributeName="opacity" values="0.0;0.8;0.0" dur="13s" repeatCount="indefinite" />
</image>
<image class="layer lighten" width="640" height="190" xlink:href="http://omnichron.net/external/op/src/meridian/glyphs.png">
    <animateTransform attributeName="transform" attributeType="XML" type="rotate" from="0 320 95" to="360 320 95" dur="97s" repeatCount="indefinite" />
    <animate attributeName="opacity" values="0.0;0.6;0.0" dur="17s" repeatCount="indefinite" />
</image>
<image class="layer" width="640" height="190" xlink:href="http://omnichron.net/external/op/src/meridian/compass.png" />
<image class="layer lighten" width="640" height="190" xlink:href="http://omnichron.net/external/op/src/meridian/rays-top.png">
    <animateTransform attributeName="transform" attributeType="XML" type="rotate" from="360 320 95" to="0 320 95" dur="87s" repeatCount="indefinite" />
    <animate attributeName="opacity" values="0.0;0.6;0.0" dur="13s" repeatCount="indefinite" />
</image>
<image class="layer" width="640" height="190" xlink:href="http://omnichron.net/external/op/src/meridian/flare-back.png" />
<image class="layer lighten" width="640" height="190" xlink:href="http://omnichron.net/external/op/src/meridian/flare-yellow.png">
    <animate attributeName="opacity" dur="60s" repeatCount="indefinite"
        keytimes="0.00;0.04;0.06;0.08;0.12;0.14;0.15;0.16;0.17;0.18;0.10;0.23;0.24;0.25;0.28;0.32;0.33;0.34;0.35;0.36;0.37;0.38;0.39;0.40;0.41;0.46;0.47;0.48;0.49;0.50;0.54;0.55;0.56;0.57;0.58;0.60;0.61;0.62;0.63;0.64;0.66;0.68;0.70;0.72;0.74;0.75;0.76;0.77;0.18;0.80;0.86;0.87;0.88;0.89;0.90;0.92;0.93;0.94;0.94;0.98;1.00"
        values="0.60;0.65;0.80;0.65;0.60;0.60;0.65;0.90;0.65;0.60;0.60;0.75;0.80;0.75;0.60;0.60;0.65;0.75;0.65;0.60;0.60;0.65;0.90;0.65;0.60;0.60;0.65;0.90;0.65;0.60;0.60;0.75;0.80;0.75;0.60;0.60;0.65;0.85;0.65;0.60;0.60;0.75;0.90;0.75;0.60;0.60;0.75;0.95;0.75;0.60;0.60;0.65;0.75;0.65;0.60;0.60;0.65;0.90;0.65;0.60;0.60"
    />
</image>
<image class="layer lighten" width="640" height="190" xlink:href="http://omnichron.net/external/op/src/meridian/flare-white.png">
    <animate attributeName="opacity" dur="60s" repeatCount="indefinite"
        keytimes="0.00;0.04;0.06;0.08;0.12;0.14;0.15;0.16;0.17;0.18;0.10;0.23;0.24;0.25;0.28;0.32;0.33;0.34;0.35;0.36;0.37;0.38;0.39;0.40;0.41;0.46;0.47;0.48;0.49;0.50;0.54;0.55;0.56;0.57;0.58;0.60;0.61;0.62;0.63;0.64;0.66;0.68;0.70;0.72;0.74;0.75;0.76;0.77;0.18;0.80;0.86;0.87;0.88;0.89;0.90;0.92;0.93;0.94;0.94;0.98;1.00"
        values="0.60;0.65;0.80;0.65;0.60;0.60;0.65;0.90;0.65;0.60;0.60;0.75;0.80;0.75;0.60;0.60;0.65;0.75;0.65;0.60;0.60;0.65;0.90;0.65;0.60;0.60;0.65;0.90;0.65;0.60;0.60;0.75;0.80;0.75;0.60;0.60;0.65;0.85;0.65;0.60;0.60;0.75;0.90;0.75;0.60;0.60;0.75;0.95;0.75;0.60;0.60;0.65;0.75;0.65;0.60;0.60;0.65;0.90;0.65;0.60;0.60"
    />
</image>
<image class="layer letters" width="640" height="190" xlink:href="http://omnichron.net/external/op/src/meridian/letters.png" />

Answer 1

In order to protect your privacy SVG must be complete in a single file when used in an image context.

If you want to have images within the SVG you'll need to encode them as data URIs.