(PECL imagick 2.0.0)
Imagick::blackThresholdImage — Forces all pixels below the threshold into black
本函数还未编写文档，仅有参数列表。
Is like Imagick::thresholdImage() but forces all pixels below the threshold into black while leaving all pixels above the threshold unchanged.
The threshold below which everything turns black
Returns TRUE on success.
| 版本 | 说明 |
|---|---|
| 2.1.0 | Now allows a string representing the color as a parameter. Previous versions allow only an ImagickPixel object. |