imagefilter
(PHP 5)
imagefilter -- Applies a filter to an image
Description
bool
imagefilter ( resource image, int filtertype [, int arg1 [, int arg2 [, int arg3]]] )
imagefilter() applies the given filter
filtertype on the image.
Parameters
imageAn 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. 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
Return Values
Returns TRUE on success or FALSE on failure.
Examples
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);
?>
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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);
?>
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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);
?>
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Notes
Note: This function is only available if
PHP is compiled with the bundled version of the GD library.
