<feColorMatrix> - SVG: Scalable Vector Graphics 编辑

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'].

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.

Usage context

Attributes

Global attributes

• Core attributes
• Presentation attributes
• Filter primitive attributes
• class
• style

Specific attributes

• in
• type
• values

DOM Interface

This element implements the 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

Screenshot	Live sample

Specifications

Browser compatibility

BCD tables only load in the browser

See also

• <filter>
• <animate>
• <set>
• <feBlend>
• <feComponentTransfer>
• <feComposite>
• <feConvolveMatrix>
• <feDiffuseLighting>
• <feDisplacementMap>
• <feFlood>
• <feGaussianBlur>
• <feImage>
• <feMerge>
• <feMorphology>
• <feOffset>
• <feSpecularLighting>
• <feTile>
• <feTurbulence>
• SVG tutorial: Filter effects