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Website Programming in PHP / MYSQL
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
]]]] )
imagefilter() applies the given filter filtertype on the image .
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.
ChangeLog
| Version | Description |
|---|---|
| 5.2.5 | Alpha support for IMG_FILTER_COLORIZE was added. |
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
$im = imagecreatefrompng('philip.png');
/* R, G, B, so 0, 255, 0 is green */
if ($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);
?>
Notes
Note: This function is only available if PHP is compiled with the bundled version of the GD library.
