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imagefilter

(PHP 5)

imagefilter — Applies a filter to an image

Popis

bool imagefilter ( resource $image , int $filtertype [, int $arg1 [, int $arg2 [, int $arg3 [, int $arg4 ]]]] )

imagefilter() applies the given filter filtertype on the image .

Parametre

image

An image resource, returned by one of the image creation functions, such as imagecreatetruecolor().

filtertype

filtertype can be one of the following:

  • IMG_FILTER_NEGATE: Reverses all colors of the image.
  • IMG_FILTER_GRAYSCALE: Converts the image into grayscale.
  • IMG_FILTER_BRIGHTNESS: Changes the brightness of the image. Use arg1 to set the level of brightness.
  • IMG_FILTER_CONTRAST: Changes the contrast of the image. Use arg1 to set the level of contrast.
  • IMG_FILTER_COLORIZE: Like IMG_FILTER_GRAYSCALE, except you can specify the color. Use arg1 , arg2 and arg3 in the form of red , blue , green and arg4 for the alpha channel. The range for each color is 0 to 255.
  • IMG_FILTER_EDGEDETECT: Uses edge detection to highlight the edges in the image.
  • IMG_FILTER_EMBOSS: Embosses the image.
  • IMG_FILTER_GAUSSIAN_BLUR: Blurs the image using the Gaussian method.
  • IMG_FILTER_SELECTIVE_BLUR: Blurs the image.
  • IMG_FILTER_MEAN_REMOVAL: Uses mean removal to achieve a "sketchy" effect.
  • IMG_FILTER_SMOOTH: Makes the image smoother. Use arg1 to set the level of smoothness.

arg1

arg2

arg3

Vrátené hodnoty

Vracia TRUE pri úspechu alebe FALSE pri chybe.

ChangeLog

Verzia Popis
5.2.5 Alpha support for IMG_FILTER_COLORIZE was added.

Príklady

Example#1 imagefilter() grayscale example

<?php
$im = imagecreatefrompng('dave.png');
if ($im && imagefilter($im, IMG_FILTER_GRAYSCALE)) {
    echo 'Image converted to grayscale.';
    imagepng($im, 'dave.png');
} else {
    echo 'Conversion to grayscale failed.';
}

imagedestroy($im);
?>

Example#2 imagefilter() brightness example

<?php
$im = imagecreatefrompng('sean.png');
if ($im && imagefilter($im, IMG_FILTER_BRIGHTNESS, 20)) {
    echo 'Image brightness changed.';
    imagepng($im, 'sean.png');
} else {
    echo 'Image brightness change failed.';
}

imagedestroy($im);
?>

Example#3 imagefilter() colorize example

<?php
$im = imagecreatefrompng('philip.png');

/* R, G, B, so 0, 255, 0 is green */
if ($im && imagefilter($im, IMG_FILTER_COLORIZE, 0, 255, 0)) {
    echo 'Image successfully shaded green.';
    imagepng($im, 'philip.png');
} else {
    echo 'Green shading failed.';
}

imagedestroy($im);
?>

Poznámky

Note: Táto funkcia je dostupná len ak bolo PHP kompilované s pribalenou verziou GD knižnice.

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