(PECL imagick 2.0.0)
Imagick::sketchImage — Simulates a pencil sketch
本函数暂无文档，仅有参数列表。
Simulates a pencil sketch. We convolve the image with a Gaussian operator of the given radius and standard deviation (sigma). For reasonable results, radius should be larger than sigma. Use a radius of 0 and Imagick::sketchImage() selects a suitable radius for you. Angle gives the angle of the blurring motion.
Returns TRUE on success.