To create a color overlay by using colorize=X[,Y], where X is the color of the overlay (hex value or color name) and Y is the opacity (Y=0..1, default 0.5).

colorize=X[,Y] | colourise=X[,Y]

Transforms the image into a black and white image.

gray=1 | grey=1

Examples

Create a duotone effect by using duotone=C1,C2[,Y], where C1 and C2 are the colors for the duotone (hex value or color name) and Y is the opacity (Y=0..1, default1).

duotone=C1,C2[,Y]