<feComponentTransfer>
**<feComponentTransfer>
** SVG 滤镜基元对每个像素的数据执行逐颜色分量的重新映射。它允许执行诸如亮度调整、对比度调整、颜色平衡或阈值等操作。
计算是在非预乘颜色值上执行的。通过将每个通道(R、G、B 和 A)修改为子元素 <feFuncR>
、<feFuncB>
、<feFuncG>
和 <feFuncA>
返回的结果来修改颜色。如果提供了多个相同的元素,则使用最后指定的元素,如果未提供元素来修改某个通道,则效果与为该通道提供了恒等变换相同。
使用上下文
属性
DOM 接口
此元素实现了 SVGFEComponentTransferElement
接口。
示例
SVG
html
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 600 300">
<defs>
<linearGradient
id="rainbow"
gradientUnits="userSpaceOnUse"
x1="0"
y1="0"
x2="100%"
y2="0">
<stop offset="0" stop-color="#ff0000"></stop>
<stop offset="0.2" stop-color="#ffff00"></stop>
<stop offset="0.4" stop-color="#00ff00"></stop>
<stop offset="0.6" stop-color="#00ffff"></stop>
<stop offset="0.8" stop-color="#0000ff"></stop>
<stop offset="1" stop-color="#800080"></stop>
</linearGradient>
<filter id="identity" x="0" y="0" width="100%" height="100%">
<feComponentTransfer>
<feFuncR type="identity"></feFuncR>
<feFuncG type="identity"></feFuncG>
<feFuncB type="identity"></feFuncB>
<feFuncA type="identity"></feFuncA>
</feComponentTransfer>
</filter>
<filter id="table" x="0" y="0" width="100%" height="100%">
<feComponentTransfer>
<feFuncR type="table" tableValues="0 0 1 1"></feFuncR>
<feFuncG type="table" tableValues="1 1 0 0"></feFuncG>
<feFuncB type="table" tableValues="0 1 1 0"></feFuncB>
</feComponentTransfer>
</filter>
<filter id="discrete" x="0" y="0" width="100%" height="100%">
<feComponentTransfer>
<feFuncR type="discrete" tableValues="0 0 1 1"></feFuncR>
<feFuncG type="discrete" tableValues="1 1 0 0"></feFuncG>
<feFuncB type="discrete" tableValues="0 1 1 0"></feFuncB>
</feComponentTransfer>
</filter>
<filter id="linear" x="0" y="0" width="100%" height="100%">
<feComponentTransfer>
<feFuncR type="linear" slope="0.5" intercept="0"></feFuncR>
<feFuncG type="linear" slope="0.5" intercept="0.25"></feFuncG>
<feFuncB type="linear" slope="0.5" intercept="0.5"></feFuncB>
</feComponentTransfer>
</filter>
<filter id="gamma" x="0" y="0" width="100%" height="100%">
<feComponentTransfer>
<feFuncR type="gamma" amplitude="4" exponent="7" offset="0"></feFuncR>
<feFuncG type="gamma" amplitude="4" exponent="4" offset="0"></feFuncG>
<feFuncB type="gamma" amplitude="4" exponent="1" offset="0"></feFuncB>
</feComponentTransfer>
</filter>
</defs>
<g font-weight="bold">
<text x="0" y="20">Default</text>
<rect x="0" y="30" width="100%" height="20"></rect>
<text x="0" y="70">Identity</text>
<rect
x="0"
y="80"
width="100%"
height="20"
style="filter:url(#identity)"></rect>
<text x="0" y="120">Table lookup</text>
<rect
x="0"
y="130"
width="100%"
height="20"
style="filter:url(#table)"></rect>
<text x="0" y="170">Discrete table lookup</text>
<rect
x="0"
y="180"
width="100%"
height="20"
style="filter:url(#discrete)"></rect>
<text x="0" y="220">Linear function</text>
<rect
x="0"
y="230"
width="100%"
height="20"
style="filter:url(#linear)"></rect>
<text x="0" y="270">Gamma function</text>
<rect
x="0"
y="280"
width="100%"
height="20"
style="filter:url(#gamma)"></rect>
</g>
</svg>
CSS
css
rect {
fill: url(#rainbow);
}
结果
规范
规范 |
---|
滤镜效果模块级别 1 # feComponentTransferElement |
浏览器兼容性
BCD 表格仅在浏览器中加载