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    imagesetinterpolation

    (PHP 5 >= 5.5.0, PHP 7, PHP 8)

    imagesetinterpolation — Set the interpolation method

    Descrizione

    imagesetinterpolation(GdImage $image, int $method = IMG_BILINEAR_FIXED): bool

    Sets the interpolation method, setting an interpolation method affects the rendering of various functions in GD, such as the imagerotate() function.

    Elenco dei parametri

    image

    Una risorsa immagine, restituita da una delle funzioni di creazione immagine, come imagecreatetruecolor().

    method

    The interpolation method, which can be one of the following:

    Valori restituiti

    Restituisce true in caso di successo, false in caso di fallimento.

    Log delle modifiche

    Versione Descrizione
    8.0.0 image expects a GdImage instance now; previously, a valid gd resource was expected.

    Esempi

    Example #1 imagesetinterpolation() example

    <?php
    // Load an image
    $im = imagecreate(500, 500);

    // By default interpolation is IMG_BILINEAR_FIXED, switch
    // to use the 'Mitchell' filter:
    imagesetinterpolation($im, IMG_MITCHELL);

    // Continue to work with $im ...
    ?>

    Note

    Changing the interpolation method affects the following functions when rendering:

    Vedere anche:

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    User Contributed Notes 1 note

    up
    -1
    shaun at slickdesign dot com dot au
    7 years ago
    Setting the interpolation does not carry through to any images created by imageaffine() or imagerotate(). It defaults to IMG_BILINEAR_FIXED and would need to be set on each generated image as required.

    <?php
    imagesetinterpolation    ( $image, IMG_NEAREST_NEIGHBOUR );

    // Rotated using IMG_NEAREST_NEIGHBOUR
    $rotated = imagerotate( $image, 45, $transparent );

    // Rotated using IMG_BILINEAR_FIXED
    $rotated_again = imagerotate( $rotated, 45, $transparent );
    ?>

    Setting the interpolation to IMG_NEAREST_NEIGHBOUR can help to preserve details and prevent sampling issues when rotating an image at 90 degree increments, including when rotating clockwise.

    <?php
    // Rotated image can appear blurred and on a slight angle.
    $rotated = imagerotate( $image, -360, $transparent );

    // Similar to starting Image although it may still show a background or be on a slight angle.
    imagesetinterpolation( $image, IMG_NEAREST_NEIGHBOUR );
    $rotated = imagerotate( $image, -360, $transparent );
    ?>
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