vignette method
void
vignette({})
Implementation
void vignette(
{num start = 0.3,
num end = 0.75,
Color? color,
num amount = 0.8,
Command? mask,
Channel maskChannel = Channel.luminance}) {
subCommand = VignetteCmd(subCommand,
start: start,
end: end,
color: color,
amount: amount,
mask: mask,
maskChannel: maskChannel);
}