ConFoo 2025

Imagick::forwardFourierTransformImage

(PECL imagick 3 >= 3.3.0)

Imagick::forwardFourierTransformImageImplements the discrete Fourier transform (DFT)

Beschreibung

public Imagick::forwardFourierTransformimage(bool $magnitude): bool

Implements the discrete Fourier transform (DFT) of the image either as a magnitude / phase or real / imaginary image pair.

Parameter-Liste

magnitude

If true, return as magnitude / phase pair otherwise a real / imaginary image pair.

Rückgabewerte

Liefert true bei Erfolg.

Beispiele

Beispiel #1 Imagick::forwardFourierTransformImage()

<?php
//Utility function for forwardTransformImage
function createMask() {
$draw = new \ImagickDraw();

$draw->setStrokeOpacity(0);
$draw->setStrokeColor('rgb(255, 255, 255)');
$draw->setFillColor('rgb(255, 255, 255)');

//Draw a circle on the y-axis, with it's centre
//at x, y that touches the origin
$draw->circle(250, 250, 220, 250);

$imagick = new \Imagick();
$imagick->newImage(512, 512, "black");
$imagick->drawImage($draw);
$imagick->gaussianBlurImage(20, 20);
$imagick->autoLevelImage();

return
$imagick;
}


function
forwardFourierTransformImage($imagePath) {
$imagick = new \Imagick(realpath($imagePath));
$imagick->resizeimage(512, 512, \Imagick::FILTER_LANCZOS, 1);

$mask = createMask();
$imagick->forwardFourierTransformImage(true);

@
$imagick->setimageindex(0);
$magnitude = $imagick->getimage();

@
$imagick->setimageindex(1);
$imagickPhase = $imagick->getimage();

if (
true) {
$imagickPhase->compositeImage($mask, \Imagick::COMPOSITE_MULTIPLY, 0, 0);
}

if (
false) {
$output = clone $imagickPhase;
$output->setimageformat('png');
header("Content-Type: image/png");
echo
$output->getImageBlob();
}

$magnitude->inverseFourierTransformImage($imagickPhase, true);

$magnitude->setimageformat('png');
header("Content-Type: image/png");
echo
$magnitude->getImageBlob();
}

?>

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