imagefilter

Description

bool imagefilter ( resource src_im, int filtertype [, int arg1 [, int arg2 [, int arg3]]] )

imagefilter() applies the filter filtertype to the image, using arg1, arg2 and arg3 where necessary.

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.

如果成功则返回 TRUE，失败则返回 FALSE。

例子 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); ?>

例子 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); ?>

例子 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); ?>