Re: 1 bit separations question

At 14:25 03/05/2019 -0600, Mark Schnegg wrote:
>Is it possible to generate 1 bit tiffs as negatives to send to our 
>platesetting system? I successfully generated positives. Taking the 1 bit 
>tiffs into photoshop ad inverting the colors did not help.

If you loaded the 1-bit TIFF files and inverted them then you would be 
inverting the halftone pattern which is not likely to be successful.

It sounds like you need to invert all the colours before applying the 
halftone (and by implication, before separating).

You don't say what your input is (PostScript, PDF, XPS, PCL, PXL) and the 
answer will be different depending on the input.

The most obvious answer would be to apply a transfer function to invert all 
the colours it is, after all, what they are for. That only works with 
PostScript or PDF though. The other solution would be a custom device (in 
Ghostscript terms) which handles all the device methods by simply inverting 
all the colours and then calling the default method in order to render the 
result.

A transfer function can be written in PostScript in a matter of seconds, a 
device would take longer, probably a week for someone who knows what they 
are doing (including altering the build system to include the new device). 
Both solutions would require significant testing.



                         Ken