docs.rodeo

{{SVGRef}}

The <feColorMatrix> SVG filter element changes colors based on a transformation matrix. Every pixel’s color value [R,G,B,A] is matrix multiplied by a 5 by 5 color matrix to create new color [R',G',B',A'].

[!NOTE] The prime symbol ' is used in mathematics indicate the result of a transformation.

| R' |     | r1 r2 r3 r4 r5 |   | R |
| G' |     | g1 g2 g3 g4 g5 |   | G |
| B' |  =  | b1 b2 b3 b4 b5 | * | B |
| A' |     | a1 a2 a3 a4 a5 |   | A |
| 1  |     | 0  0  0  0  1  |   | 1 |

In simplified terms, below is how each color channel in the new pixel is calculated. The last row is ignored because its values are constant.

R' = r1*R + r2*G + r3*B + r4*A + r5
G' = g1*R + g2*G + g3*B + g4*A + g5
B' = b1*R + b2*G + b3*B + b4*A + b5
A' = a1*R + a2*G + a3*B + a4*A + a5

Take the amount of red in the new pixel, or R':

It is the sum of:

r1 times the old pixel’s red R,
r2 times the old pixel’s green G,
r3 times of the old pixel’s blue B,
r4 times the old pixel’s alpha A,
plus a shift r5.

These specified amounts can be any real number, though the final R’ will be clamped between 0 and 1. The same goes for G’, B’, and A’.

R'      =      r1 * R      +        r2 * G      +       r3 * B      +       r4 * A       +       r5
New red = [ r1 * old red ] + [ r2 * old green ] + [ r3 * old Blue ] + [ r4 * old Alpha ] + [ shift of r5 ]

If, say, we want to make a completely black image redder, we can make the r5 a positive real number x, boosting the redness on every pixel of the new image by x.

An identity matrix looks like this:

     R G B A W
R' | 1 0 0 0 0 |
G' | 0 1 0 0 0 |
B' | 0 0 1 0 0 |
A' | 0 0 0 1 0 |

In it, every new value is exactly 1 times its old value, with nothing else added. It is recommended to start manipulating the matrix from here.

Like other filter primitives, it handles color components in the linearRGB {{glossary("color space")}} by default. You can use {{svgattr("color-interpolation-filters")}} to use sRGB instead.

Usage context

{{svginfo}}

Attributes

{{SVGAttr("in")}} : Values include SourceGraphic, SourceAlpha, BackgroundImage, BackgroundAlpha, FillPaint, StrokePaint, or a reference to another filter primitive.
{{SVGAttr("type")}} : Values include matrix, saturate, hueRotate, and luminanceToAlpha.
{{SVGAttr("values")}} : The value for the matrix type set in the type attribute.

DOM Interface

This element implements the {{domxref("SVGFEColorMatrixElement")}} interface.

Example

SVG

<svg
  width="100%"
  height="100%"
  viewBox="0 0 150 500"
  preserveAspectRatio="xMidYMid meet"
  xmlns="http://www.w3.org/2000/svg"
  xmlns:xlink="http://www.w3.org/1999/xlink">
  <!-- ref -->
  <defs>
    <g id="circles">
      <circle cx="30" cy="30" r="20" fill="blue" fill-opacity="0.5" />
      <circle cx="20" cy="50" r="20" fill="green" fill-opacity="0.5" />
      <circle cx="40" cy="50" r="20" fill="red" fill-opacity="0.5" />
    </g>
  </defs>
  <use href="#circles" />
  <text x="70" y="50">Reference</text>

  <!-- identity matrix -->
  <filter id="colorMeTheSame">
    <feColorMatrix
      in="SourceGraphic"
      type="matrix"
      values="1 0 0 0 0
              0 1 0 0 0
              0 0 1 0 0
              0 0 0 1 0" />
  </filter>
  <use
    href="#circles"
    transform="translate(0 70)"
    filter="url(#colorMeTheSame)" />
  <text x="70" y="120">Identity matrix</text>

  <!-- Combine RGB into green matrix -->
  <filter id="colorMeGreen">
    <feColorMatrix
      in="SourceGraphic"
      type="matrix"
      values="0 0 0 0 0
              1 1 1 1 0
              0 0 0 0 0
              0 0 0 1 0" />
  </filter>
  <use
    href="#circles"
    transform="translate(0 140)"
    filter="url(#colorMeGreen)" />
  <text x="70" y="190">rgbToGreen</text>

  <!-- saturate -->
  <filter id="colorMeSaturate">
    <feColorMatrix in="SourceGraphic" type="saturate" values="0.2" />
  </filter>
  <use
    href="#circles"
    transform="translate(0 210)"
    filter="url(#colorMeSaturate)" />
  <text x="70" y="260">saturate</text>

  <!-- hueRotate -->
  <filter id="colorMeHueRotate">
    <feColorMatrix in="SourceGraphic" type="hueRotate" values="180" />
  </filter>
  <use
    href="#circles"
    transform="translate(0 280)"
    filter="url(#colorMeHueRotate)" />
  <text x="70" y="330">hueRotate</text>

  <!-- luminanceToAlpha -->
  <filter id="colorMeLTA">
    <feColorMatrix in="SourceGraphic" type="luminanceToAlpha" />
  </filter>
  <use href="#circles" transform="translate(0 350)" filter="url(#colorMeLTA)" />
  <text x="70" y="400">luminanceToAlpha</text>
</svg>

Result

{{EmbedLiveSample("Example", "100%", "700")}}

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

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