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    imagesetinterpolation

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

    imagesetinterpolation — Set the interpolation method

    Descrição

    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.

    Parâmetros

    image

    Um objeto GdImage, retornado por uma das funções de criação de imagem, como imagecreatetruecolor().

    method

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

    • IMG_BELL: Bell filter.
    • IMG_BESSEL: Bessel filter.
    • IMG_BICUBIC: Bicubic interpolation.
    • IMG_BICUBIC_FIXED: Fixed point implementation of the bicubic interpolation.
    • IMG_BILINEAR_FIXED: Fixed point implementation of the bilinear interpolation (default (also on image creation)).
    • IMG_BLACKMAN: Blackman window function.
    • IMG_BOX: Box blur filter.
    • IMG_BSPLINE: Spline interpolation.
    • IMG_CATMULLROM: Cubic Hermite spline interpolation.
    • IMG_GAUSSIAN: Gaussian function.
    • IMG_GENERALIZED_CUBIC: Generalized cubic spline fractal interpolation.
    • IMG_HERMITE: Hermite interpolation.
    • IMG_HAMMING: Hamming filter.
    • IMG_HANNING: Hanning filter.
    • IMG_MITCHELL: Mitchell filter.
    • IMG_POWER: Power interpolation.
    • IMG_QUADRATIC: Inverse quadratic interpolation.
    • IMG_SINC: Sinc function.
    • IMG_NEAREST_NEIGHBOUR: Nearest neighbour interpolation.
    • IMG_WEIGHTED4: Weighting filter.
    • IMG_TRIANGLE: Triangle interpolation.

    Valor Retornado

    Retorna true em caso de sucesso ou false em caso de falha.

    Registro de Alterações

    Versão Descrição
    8.0.0 O parâmetro image agora espera uma instância de GdImage; anteriormente, um resource gd válido era esperado.

    Exemplos

    Exemplo #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 ...
    ?>

    Notas

    Changing the interpolation method affects the following functions when rendering:

    Veja Também

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    User Contributed Notes 1 note

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    -1
    shaun at slickdesign dot com dot au
    6 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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