Transform Options
Transform options manipulate an image's size, orientation, and color mode.
This section discusses the following options:
dpi=<-1200 to -25, 0, 25 to 1200>
vflip
hflip
rotate=<angle>
invert
upsample=<factor>
subsample=<factor>
layer=<layer_type>
crop=<x0>,<y0>,<w>x<h>
resize=<w>x<h>
togray
tobitonal=[<1-255>]
black-normalize=<-1, 0-100>
white-normalize=<-1, 0-100>
scale-normalize=<1- >
jpeg