Yahoo Groups archive

Digital BW, The Print

Index last updated: 2026-04-28 22:56 UTC

Message

Re: [Digital BW] Moire

2014-03-26 by Ernst Dinkla

On 26-03-14 11:45, Peter Marquis-Kyle wrote:
> On 26/03/2014 8:15 PM, Stephen Petegorsky wrote:
>> Peter - is the print something you can shoot or scan again, or do you not have access to the original?
>>
>> If you can re-do it, try shooting it from a greater distance and/or at a rotation of 15-45 degrees from level.  If you don't have a RAW file and access to software like Phocus or something similar that has an option to treat moire, I doubt that you will have much luck trying to improve the file.
>
> Thanks Stephen. Yes, I do have the original, and I am working with a
> flatbed scan. I don't think rotating the original will help, since the
> engraved lines run in various directions. There is no dot screen here,
> only hand-engraved lines on end-grain boxwood. Did you look at the image
> on the web page I linked to? -- you can enlarge it to see the engraved
> lines.
>
> --
>
> Peter Marquis-Kyle
>

Scan at the highest resolution possible, print at the highest resolution 
possible (finest detail set) so upsampling is done on the data. Quite 
often downsampling without anti-aliasing applied makes things worse.  If 
the print may vary in size there is a good chance it will print with 
less moir\ufffd at another size. If the moir\ufffd started with the scan and shows 
in all sizes on the monitor it will appear in print too. Try to find an 
angle in the scanner that gives the least moir\ufffd. Make sure that the 
original is as flat as possible on the scanner. If the tools to take out 
raster screening moir\ufffd do not work add some noise or grain. Vary the 
image in size on the monitor, what is moir\ufffd at one size disappears or 
changes at another size, if that happens you have better chances in the 
print.


-- 
Met vriendelijke groet, Ernst

http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
January 2014, 600+ inkjet media white spectral plots.

Attachments

Move to quarantaine

This moves the raw source file on disk only. The archive index is not changed automatically, so you still need to run a manual refresh afterward.