Does SVG support embedding of bitmap images?

问题

Is an SVG image purely vectorial or can we combine bitmap images into an SVG image ? How about transforms applied on the bitmap images (perspective, mappings, etc.) ?

Edit: Images may be included in an SVG by link reference. See http://www.w3.org/TR/SVG/struct.html#ImageElement. My question was in fact if bitmap images may be included inside the svg so that the svg image would be self contained. Otherwise, whenever the svg image is displayed the link must be followed and the image downloaded. Apparently .svg files are simply xml files.

回答1:

Yes, you can reference any image from the <image> element. And you can use data uri's to make the svg fully selfcontained. An example:

<image width="100" height="100" xlink:href="data:image/png;base64,...">

The dots is where you'd add the encoded base64 data, vector graphics editors that support svg usually have an option for saving with images embedded. Otherwise there are plenty of tools around for encoding to and from base64.

Here's a full example from the svg testsuite.

回答2:

I posted a fiddle here, showing data, remote and local images embedded in SVG, inside an HTML page:

http://jsfiddle.net/MxHPq/

<!DOCTYPE html>
<html>
<head>
    <title>SVG embedded bitmaps in HTML</title>
    <style>

        body{
            background-color:#999;
            color:#666;
            padding:10px;
        }

        h1{
            font-weight:normal;
            font-size:24px;
            margin-top:20px;
            color:#000;
        }

        h2{
            font-weight:normal;
            font-size:20px;
            margin-top:20px;
        }

        p{
            color:#FFF;
            }

        svg{
            margin:20px;
            display:block;
            height:100px;
        }

    </style>
</head>

<body>
    <h1>SVG embedded bitmaps in HTML</h1>
    <p>The trick appears to be ensuring the image has the correct width and height atttributes</p>

    <h2>Example 1: Embedded data</h2>
    <svg id="example1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
        <image x="0" y="0" width="5" height="5" xlink:href="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAYAAACNbyblAAAAHElEQVQI12P4//8/w38GIAXDIBKE0DHxgljNBAAO9TXL0Y4OHwAAAABJRU5ErkJggg=="/>
    </svg>

    <h2>Example 2: Remote image</h2>
    <svg id="example2" version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
        <image x="0" y="0" width="275" height="95" xlink:href="http://www.google.co.uk/images/srpr/logo3w.png" />
    </svg>

    <h2>Example 3: Local image</h2>
    <svg id="example3" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
        <image x="0" y="0" width="136" height="23" xlink:href="/img/logo.png" />
    </svg>


</body>
</html>

回答3:

You could use a Data URI to supply the image data, for example:

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

<image width="20" height="20" xlink:href="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAYAAACNbyblAAAAHElEQVQI12P4//8/w38GIAXDIBKE0DHxgljNBAAO9TXL0Y4OHwAAAABJRU5ErkJggg=="/>

</svg>

The image will go through all normal svg transformations.

But this technique has disadvantages, for example the image will not be cached by the browser

回答4:

You can use a data: URL to embed a Base64 encoded version of an image. But it's not very efficient and wouldn't recommend embedding large images. Any reason linking to another file is not feasible?

回答5:

It is also possible to include bitmaps. I think you also can use transformations on that.

来源：https://stackoverflow.com/questions/6249664/does-svg-support-embedding-of-bitmap-images

标签

image

svg

bitmapimage