Rampage Imposed Tiff to Prinergy

[lnivin]

We thought it would be easy, but no. We're trying to take Rampage bitmapped tiffs to Prinergy. The file is imposed and created with round dots.

If we send it to the Lotem front end, it doesn't like it because it won't pass the license feature.

If we Refine through Prinergy, the file sent looks as if it has been seamed every inch or so. The dots are there, but looked slightly clipped and is viewable on plate and in VPS.

Since these are bitmapped dots, I'm surprised Prinergy is trying to do anything with them.

Has anyone seen this? Have a solution?

Thanks,
Linda

 

[HenkvanGerwen]

We thought it would be easy, but no. We're trying to take Rampage bitmapped tiffs to Prinergy. The file is imposed and created with round dots.

If we send it to the Lotem front end, it doesn't like it because it won't pass the license feature.

If we Refine through Prinergy, the file sent looks as if it has been seamed every inch or so. The dots are there, but looked slightly clipped and is viewable on plate and in VPS.

Since these are bitmapped dots, I'm surprised Prinergy is trying to do anything with them.

Has anyone seen this? Have a solution?

Thanks,
Linda

Just send the file over to Rampage support and they will give you the right answer Linda.

 

[duffman]

We thought it would be easy, but no. We're trying to take Rampage bitmapped tiffs to Prinergy. The file is imposed and created with round dots.

If we send it to the Lotem front end, it doesn't like it because it won't pass the license feature.

If we Refine through Prinergy, the file sent looks as if it has been seamed every inch or so. The dots are there, but looked slightly clipped and is viewable on plate and in VPS.

Since these are bitmapped dots, I'm surprised Prinergy is trying to do anything with them.

Has anyone seen this? Have a solution?

Thanks,
Linda

Xitron might have a solution. Contact at 734-913-8080

 

[Stephen Marsh]

Can you perform a "BypassRefine" instead of a regular (normalization) refine?


Stephen Marsh

 

[SZmetana]

Rampage Imposed Tiff to Prinergy

Hi Linda,

You are correct in your assumption that Prinergy normally doesn't touch 1-bit TIFF data in an input file. The seams you see in a PDF are simply how Acrobat (or virtually any program) displays high-resolution 1-bit data on a monitor. Depending on the resolution of the monitor and the zoom factor, the seams will get more or less pronounced. Also, when viewing in VPS you may see moire patterns, depending on the zoom factor. This is caused by interference between the monitor pixels and the 1-bit data in the file. To get an accurate viewing of how the 1-bit data will output to plate, create a VPS at the same resolution as the Lotem (100 lcm/2540 dpi or 94 lcm/2400?) and view at a 1-1 zoom (you should also be fine viewing at even multiples, like 2:1, 4:1 or 8:1.)

So just because the display looks weird in Acrobat or VPS, it doesn't mean the files will output with artifacts.

However, you say that you can see artifacts when the results are plated.

The artifacts you see are likely the result of a resolution mismatch between the input TIFF data and the device head resolution. For instance, if the 1-bit TIFF data is 2400 dpi and the output device is 2540 dpi, you will get patterning. This is because the output device needs to resample the TIFF data to match the resolution of the imaging head. In order to do this, the device simply adds or removes pixels in straight rows or columns, resulting in noticeable patterns in the output results. Generally these artifacts look like scan lines when viewed at normal "reading distance". Zoomed in, you should see that the edges of dots are flattened -- and this is what you seem to report.

Also bear in mind that if the underlying 1-bit TIFF is scaled up or down in the layout, this effectively changes the resolution and will result in patterns. So even if the 1-bit data is at 2400 dpi and is being output on a 2400 dpi device, if the TIFF is scaled down to (eg.) 97%, this effectively increases its resolution to 2474.2 dpi and will result in artifacts.

In order to prevent artifacts due to mismatched resolutions or scaling, we provide the Copydot resampling engine. The Prinergy Copydot JTP will resample the 1-bit TIFF data contained in input files to the final device resolution. When the Copydot JTP resamples the data, it randomizes pixel removal so that there are no visible artifacts. Copydot resampling can be done at the time of Refine, to convert the 1-bit data in the digital master PDF to device resolution, or resampling can be done on the fly at the time of Output. The Copydot JTP is a chargeable option for Prinergy.

So even thought the TIFF may looks strange when viewed in Acrobat or in VPS, if the 1-bit data is at the same resolution as the output device and has not been scaled, it should output without any artifacts. But for mismatched resolutions, you must resample the 1-bit data to match the device head resolution -- or you'll be in trouble.

Regards,
Stephen Zmetana
Global Product Support, Kodak Unified Workflow

 

[lnivin]

I tried processing through Copydot to 2400dpi (even though it is supplied 2400dpi). It still had the seams, although perhaps not as pronounced.

Actually what happens is approx every 1-inch the dot's have a square side instead of round. They appear larger, not smaller. I checked using 2400dpi VPS. The image has not been scaled throughout the workflow.

We're using Prinergy 4, so we don't have the Bypass option.

I appreciate all ideas given!

 

[Stephen Marsh]

Can you convert the 1 bit TIFFs to PDF, then refine the PDF?


Stephen Marsh