Raster data for Pure black text printing

[shermin]

Hi,
 1)In pstoraster code ,cups_map_rgb() there is a calculation for max K value.What is the use of this max K value and how the cal is done.(k*k*k/mk*mk)

2)Code for finding the type of object rendered is in esp ghostscript.or in Ghostscript??I tried searching the code for this for the past 4 days but still couldnt find the hook.


Shermin

> shermin wrote:
> > Hi,
> > One of the RIP used for CUPS is pstoraster right?So if i want to
> > modify only the cmyk separation in my RIP,do i need to add only a
> > patch of code for pstoraster as RIP for my device  and whether all
> > the rest of things will be done by pstoraster???
>
> Yes; if you look at the gdevcups.c code, it is responsible for
> generating the CMYK separation - you could modify the color mapping
> code to only use K for 100% black (RGB = 0,0,0), and there are other
> hooks (that the current code does not use) for getting the type of
> object being rendered.
>
> Note, however, that if you replace the system Ghostscript with your
> own you WILL break things.
>
> > 2)How will i bring my RIP in between the pstoraster execution.?
>
> You don't, you have to completely replace the pstoraster
> functionality, either by replacing Ghostscript with your own version
> or providing a separate copy that implements the color separation
> behavior you want.
>
> .....
>
> FWIW, it is probably far easier to just take RGB and map grayscale
> values to the K channel when adjacent pixels are also grayscale.  This
> approach would also work on platforms where Ghostscript is not used...
>
> --
> ______________________________________________________________________
> Michael R Sweet                        Senior Printing System Engineer
>