operator

The operator attribute as two meanings based on the context itʼs used in. Either it defines the compositing or morphing operation to be performed.

Two elements are using this attribute: <feComposite> and <feMorphology>

html, body, svg {
  height: 100%;
  font: 20px Arial, Helvetica, sans-serif;
}

<svg viewBox="0 0 120 70" xmlns="http://www.w3.org/2000/svg">
  <filter id="erode">
    <feMorphology operator="erode" radius="0.4"/>
  </filter>
  <filter id="dilate">
    <feMorphology operator="dilate" radius="0.8"/>
  </filter>

  <text x="0" y="15">Normal text</text>
  <text x="0" y="40" filter="url(#erode)">Thin text</text>
  <text x="0" y="65" filter="url(#dilate)">Fat text</text>
</svg>

feComposite

For <feComposite>, operator defines the compositing operation that is to be performed.

over

This value indicates that the source graphic defined in the in attribute is placed over the destination graphic defined in the in2 attribute.

in

This value indicates that the parts of the source graphic defined in the in attribute that overlap the destination graphic defined in the in2 attribute, replace the destination graphic.

out

This value indicates that the parts of the source graphic defined in the in attribute that fall outside the destination graphic defined in the in2 attribute, are displayed.

atop

This value indicates that the parts of the source graphic defined in the in attribute, which overlap the destination graphic defined in the in2 attribute, replace the destination graphic. The parts of the destination graphic that do not overlap with the source graphic stay untouched.

xor

This value indicates that the non-overlapping regions of the source graphic defined in the in attribute and the destination graphic defined in the in2 attribute are combined.

lighter

This value indicates that the sum of the source graphic defined in the in attribute and the destination graphic defined in the in2 attribute is displayed.

arithmetic

This value indicates that the source graphic defined in the in attribute and the destination graphic defined in the in2 attribute are combined using the following formula:

result = k1*i1*i2 + k2*i1 + k3*i2 + k4

where:
i1 and i2 indicate the corresponding pixel channel values of the input image, which map to in and in2 respectively, and k1,k2,k3,and k4 indicate the values of the attributes with the same name.

feMorphology

For <feMorphology>, operator defines whether to erode (i.e., thin) or dilate (fatten) the source graphic.

erode

This value thins the source graphic defined in the in attribute.

dilate

This value fattens the source graphic defined in the in attribute.

Specifications