imagefilter
(PHP 5)
imagefilter — Applies a filter to an image
Description
bool imagefilter
( resource $image
, int $filtertype
[, int $arg1
[, int $arg2
[, int $arg3
[, int $arg4
]]]] )
Parameters
-
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
-
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);
?>
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
$im = imagecreatefrompng('philip.png');
if ($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);
?>
Notes
Note: This function is only available if
PHP is compiled with the bundled version of the GD library.
imagefilltoborder
