imagefilter
imagefilter applies the given filter filter on the image.
Parameters
- image
A GdImage object, returned by one of the image creation functions, such as imagecreatetruecolor.
- filter
-
filter can be one of the following:
IMG_FILTER_NEGATE: Reverses all colors of the image.
IMG_FILTER_GRAYSCALE: Converts the image into grayscale by changing the red, green and blue components to their weighted sum using the same coefficients as the REC.601 luma (Y') calculation. The alpha components are retained. For palette images the result may differ due to palette limitations.
IMG_FILTER_BRIGHTNESS: Changes the brightness of the image. Use args to set the level of brightness. The range for the brightness is -255 to 255.
IMG_FILTER_CONTRAST: Changes the contrast of the image. Use args to set the level of contrast.
IMG_FILTER_COLORIZE: Like IMG_FILTER_GRAYSCALE, except you can specify the color. Use args, arg2 and arg3 in the form of red, green, blue 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 args to set the level of smoothness.
IMG_FILTER_PIXELATE: Applies pixelation effect to the image, use args to set the block size and arg2 to set the pixelation effect mode.
IMG_FILTER_SCATTER: Applies scatter effect to the image, use args and arg2 to define the effect strength and additionally arg3 to only apply the on select pixel colors.
- args
-
IMG_FILTER_BRIGHTNESS: Brightness level.
IMG_FILTER_CONTRAST: Contrast level.
IMG_FILTER_COLORIZE: Value of red component.
IMG_FILTER_SMOOTH: Smoothness level.
IMG_FILTER_PIXELATE: Block size in pixels.
IMG_FILTER_SCATTER: Effect substraction level. This must not be higher or equal to the addition level set with arg2.
- arg2
-
IMG_FILTER_COLORIZE: Value of green component.
IMG_FILTER_PIXELATE: Whether to use advanced pixelation effect or not (defaults to false).
IMG_FILTER_SCATTER: Effect addition level.
- arg3
-
IMG_FILTER_COLORIZE: Value of blue component.
IMG_FILTER_SCATTER: Optional array indexed color values to apply effect at.
- arg4
-
IMG_FILTER_COLORIZE: Alpha channel, A value between 0 and 127. 0 indicates completely opaque while 127 indicates completely transparent.
Return Values
Returns true on success or false on failure.
Notes
Note:
The result of IMG_FILTER_SCATTER is always random.
Changelog
| Version | Description |
| 8.0.0 | image expects a GdImage instance now; previously, a resource was expected. |
| 7.4.0 | Scatter support (IMG_FILTER_SCATTER) was added. |