Imagick::blackThresholdImage

(PECL imagick 2.0.0)

Imagick::blackThresholdImage — Forces all pixels below the threshold into black

bool Imagick::blackThresholdImage ( mixed $threshold )

Is like Imagick::thresholdImage() but forces all pixels below the threshold into black while leaving all pixels above the threshold unchanged.

成功时返回 TRUE。

版本	说明
2.1.0	Now allows a string representing the color as a parameter. Previous versions allow only an ImagickPixel object.