(PECL imagick 2.0.0)
ImagickDraw::setTextUnderColor — Specifies the color of a background rectangle
This function is currently not documented; only its argument list is available.
Specifies the color of a background rectangle to place under text annotations.
under_colorthe under color
No value is returned.
Example #1 ImagickDraw::setTextUnderColor()
<?php
function setTextUnderColor($strokeColor, $fillColor, $backgroundColor, $textUnderColor) {
    $draw = new \ImagickDraw();
    $draw->setStrokeColor($strokeColor);
    $draw->setFillColor($fillColor);
    $draw->setStrokeWidth(2);
    $draw->setFontSize(72);
    $draw->annotation(50, 75, "Lorem Ipsum!");
    $draw->setTextUnderColor($textUnderColor);
    $draw->annotation(50, 175, "Lorem Ipsum!");
    $imagick = new \Imagick();
    $imagick->newImage(500, 500, $backgroundColor);
    $imagick->setImageFormat("png");
    $imagick->drawImage($draw);
    header("Content-Type: image/png");
    echo $imagick->getImageBlob();
}
?>