(PHP 5 >= 5.5.0)
imagesetinterpolation — Set the interpolation method
$image
[, int $method = IMG_BILINEAR_FIXED
] )Sets the interpolation method, setting an interpolation method affects the rendering of various functions in GD, such as the imagerotate() function.
image
由图象创建函数(例如 imagecreatetruecolor())返回的图象资源。
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: Cubbic 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.
成功时返回 TRUE， 或者在失败时返回 FALSE。
Example #1 imagesetinterpolation() example
<?php
// Load an image
$im = imagecreate(500, 500);
// By default interpolation is IMG_BICUBIC_FIXED, switch
// to use the 'Mitchell' filter:
imagesetinterpolation($im, IMG_MITCHELL);
// Continue to work with $im ...
?>
Changing the interpolation method affects the following functions when rendering: