Curious about 1 Bit

[Joe]

Originally Posted by Prathap

Whenever a file is RIPed it converts the CT/LW into bitmap data.
Now during this process of conversion, the file is subjected to screening where the screen angles & the frequency are applied to the data.
This data is now used for either for Imposition as per my friend "Earendil" or can be Output directly to a device.

I doubt if there are very many people that are imposing screened one-bit tif files. I think the conversion to screened one-bit tifs is done after imposition.

[Earendil]

Correct Joe! I have used Preps with an old Dolev PSM and impositioned full res files... Bad idea! Takes way too long to do anything.

I haven't used Xiflow or Navigator, we are using Xenith Xitron Extreme and I love it. I don't use the screened hi res tiff for imposition but rather the low res placment files (36dpi eps file).

In my workflow, when you RIP a job it creates a new job ticket within the workflow. That job ticket contains both the low res and high res files and they are linked together. I impose the low res files in preps and print out of preps, back into the workflow and the workflow knows to replace the placement files with the hi res (sideline) files when I release the file to the Raster Blaster plate queue. By the time the separation gets to Raster Blaster, it is a large composite 1 bit tiff that images to the plate.

The only part of this process that takes much time is the ripping of the original PDF.

[DCurry]

Originally Posted by Earendil

In this case it gets rendered to a tiff at the end of the game, just before imaging, but it does become an image, and probably a tiff, before the plotter gets a hold of it.

If so, it does it transparently on-the-fly becasue there is no intermediate file being generated. When I queue up plates, it immediately begins to image them from the CT/LW files.

[Earendil]

Yeah, the LW had me a little confused too since I know you can't image vector as vector but this article cleared it up. The LW isn't really vector, it's just has a lot more resolution than the CT...

"Scitex LW/CT--The CT format is an uncompressed raster file that includes all of the original raster picture information assembled according to the final layout. The Linework file contains any information that was originally vector prior to rasterization and was rasterized at a higher resolution than the CT in order to maintain the necessary detail required for fonts, and other vector graphics. Since this raster file could be very large due to the resolutions used (typically in the 1800 dpi to 3500 dpi range), Scitex uses RLE compression to reduce the file size. In an effort to address a 248-color area limitation of the original LW format, Scitex developed NLW. This new format extends the available color areas to about 16,000, which allow for smooth LW blends and other value-added benefits."

It's really a great article, here's the link...

FILE FORMAT BINGO

This is a great topic BTW!