feFlood filter

Fill a rectangle with flood-color and flood-opacity selected.

parameters:

flood-color : color to fill rectangle
flood-opacity : opacity for filling
result : name of RGBA raster

Tool: change parameters to compose picture with rectangle colored

Example of code:

<defs>
<filter id="MyFilter" filterUnits="userSpaceOnUse" x="0" y="0" width="400" height="400">
<feImage xlink:href='#MyImage' result='pict1'/>
<feFlood flood-color="red" flood-opacity='0.3' result='pict2'/>
<feComposite in='pict1' in2='pict2' operator="arithmetic" k1="0" k2="0.7" k3="0.7" k4="0"/>
</filter>
<image id="MyImage" width='400' height='400' xlink:href='fondu1.jpg'/>
</defs>
<use filter="url(#MyFilter)" x='0' y='0'/>