Imagick::levelImage
(No version information available, might be only in CVS)
Imagick::levelImage — Adjusts the levels of an image
Description
bool Imagick::levelImage
( float $blackPoint
, float $gamma
, float $whitePoint
[, int $channel
] )
WarningThis function is
currently not documented; only its argument list is available.
Adjusts the levels of an image by scaling the colors falling
between specified white and black points to the full
available quantum range. The parameters provided represent
the black, mid, and white points. The black point specifies
the darkest color in the image. Colors darker than the black
point are set to zero. Mid point specifies a gamma
correction to apply to the image. White point specifies the
lightest color in the image. Colors brighter than the white
point are set to the maximum quantum value.
Parameters
-
blackPoint
-
The image black point
-
gamma
-
The gamma value
-
whitePoint
-
The image white point
-
channel
-
Provide any channel constant that is valid for your channel mode. To
apply to more than one channel, combine channeltype constants using
bitwise operators. Defaults to Imagick::CHANNEL_ALL. Refer to this
list of channel constants.
Return Values
Returns TRUE on success.
Errors/Exceptions
Throws ImagickException on error.