Imagick
PHP Manual

Imagick::thresholdImage

Changes the value of individual pixels based on a threshold

Description

bool Imagick::thresholdImage ( float $threshold [, int $channel = Imagick::CHANNEL_ALL ] )

Changes the value of individual pixels based on the intensity of each pixel compared to threshold. The result is a high-contrast, two color image.

Parameters

threshold

channel

Return Values

Returns TRUE on success.