The Imagick::getImageChannelExtrema() function is an inbuilt function in PHP which is used to get the extrema for one or more image channels. Extrema are the points at which a maximum or minimum value of a function is observed. It returns an associative array with the keys “minima” and “maxima”.
Syntax:
array Imagick::getImageChannelExtrema(int $channel)
Parameters: This function accepts single parameter $channel which specifies the channel constant that is valid for your channel mode. Use bitwise operator to combine channeltype constants.
Exceptions: This function throws ImagickException on error.
Return Value: This function returns TRUE on success.
Below programs illustrate the Imagick::getImageChannelExtrema() function in PHP:
Program 1:
<?php // Create new imagick object $imagick = new Imagick( // Get the extrema with CHANNEL constant as 0 // which corresponds to imagick::CHANNEL_UNDEFINED $extrema = $imagick->getImageChannelExtrema(0); print_r($extrema); ?> |
Output:
Array ( [minima] => 0 [maxima] => -9223372036854775808 )
Program 2:
<?php // Create new imagick object $imagick = new Imagick( // Get the extrema with CHANNEL constant as 6 // which corresponds to imagick::CHANNEL_BLUE $extrema = $imagick->getImageChannelExtrema(6); print_r($extrema); ?> |
Output:
Array ( [minima] => 5654 [maxima] => 65535 )
Reference: https://www.php.net/manual/en/imagick.getimagechannelextrema.php
