--TEST-- imagefilter() function test --EXTENSIONS-- gd --SKIPIF-- --FILE-- --EXPECT-- IMG_FILTER_NEGATE success IMG_FILTER_GRAYSCALE success IMG_FILTER_EDGEDETECT success IMG_FILTER_GAUSSIAN_BLUR success IMG_FILTER_SELECTIVE_BLUR success IMG_FILTER_EMBOSS success IMG_FILTER_MEAN_REMOVAL success IMG_FILTER_SMOOTH success IMG_FILTER_COLORIZE success IMG_FILTER_CONTRAST success IMG_FILTER_BRIGHTNESS success IMG_FILTER_PIXELATE success IMG_FILTER_SCATTER success