Imagick::forwardFourierTransformImage

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Imagick::forwardFourierTransformImage — Description

说明

public void Imagick::forwardFourierTransformimage ( bool $magnitude )

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

参数

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

返回值

范例

Example #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 ();
}

 ?>