Please, allow color pages to be pass-through with a new --monochrome option.

[rbrito]

Dear @jwilk,

I have some files that feature a color page (a cover, usually) and the rest being all grayscale or monochrome and I would love to pass the options --lossy to pdf2djvu to operate on such pages only.

I do understand why pdf2djvu doesn't allow this kind of option to be passed (and why it doesn't make sense), but would it be possible to add an option just like --monochrome (perhaps something like --grayscale-as-monochrome) that allows such "pass-through" of the color pages and allows the --lossy switch on all the rest?

Thanks in advance,

Rogério Brito.