Descreening

[s.winders]

I keep reading really good things about a product called Silver Fast,its a third party scanning application,which apparently is, or alledgedly is the best out for being able to adjust your scans quite meticulously.

I assume they are at silverfast.com,and the company name is Laser Soft Imaging.


Stu. [img]/infopop/emoticons/icon_smile.gif[/img]

[Klaus Nordby]

Thanks, I too have heard of Silver Fast but never seen their software. I now dowloaded the trial version for my Epson Perfection 1640 Photo scanner(a great scanner with so-so software), and Silver Fast is indeed very good at descreening - and much else besides! But it's $150 for my scanner - more than one third the price of my scanner. Still, it could be worth it. So I advise you others to check out Silver Fast - they have versions for just about all scanners, it seems, variying greatly in price.

K

[Klaus Nordby]

Michael, I have downloaded your Action and shall try it now - thanks!


K

[s.winders]

Klaus,I have an Epson 1240,and in the smart panel setup there is an option for setting up descreen for all scanning to remove moire.I asume you know this though? Although you can only use it for some image sizes,which is why you are looking for better software right?


Stu

[Klaus Nordby]

I now see that there is also a Silver Fast SE - a smaller version - for just $49! I've tried the demo, and it's great! Check it out, if you need descreening and other advanced scanning functions for a reasonable price. I think I will buy it - once I somehow can get hold of $49. :-)


K

[Klaus Nordby]

Stu, I've been using the Twain interface, since I HATE that kind of simple-minded, cute interface of Epson's Smart Panel. But I see you are right: it does have a highly limited, non-configurable descreeing function, and it works quite well. Good quality descreening, though the non-configurableness is annoying.

It will tide me over, until I get hold of $49 for buying SilverFast.

K

[Beth]

Phew, glad to see the forums still here. I had the forum page bookmarked and I kept getting server cant be found. With a momentary glint of wisdom, I checked talkgraphics.com. phew. Guess we changed addresses or IP's or something.

Erik, I went to AGFA's site and found the URL:
http://support.agfa.com/swPubDTP/

It looks like it will work with snapscan. There is a whole wack of snapscanners listed (I randomly checked a couple). I downloaded it too...Although I probably will never hook the scanner up to my windows machine again (but you never know). So if you cant find it, I can send it to you. Its around 4 megs.

[s.winders]

I have read recently that noise in images can normally be found in the blue channel,and that about .5 of Gaussian blur cleans it up nicely,would this work for moire as well? if so you wouldnt have to worry about scanning on an angle etc anymore would you?


Stu.

[mikeius]

Beth sorry for being late.

There is several things we should consider when eliminating moire.

1. Black is the Key in printing. It should be preserved.

2. Each plate is printed using different angles. We need to study the image to select how are we going to place it in the scanner to preserve particular colors.

3. We can blur colors independently of luminosity.

4. Automatically descreen filters and/or applications remove moire, but they destroy valuable information. They can't think, we do.

All these points are considered in my actions. This actions have dialogs with instructions. Follow them, or run the action step by step and you will see the process.

Regards

[Beth]

Thanks Michael

You know, I dont even know how the scanner software descreens. THe results are very good, but as you said, the results of doing it yourself can be better.

You mentioned screen angles and placement on the scanner bed. Does this mean that you scan in different inks at different angles. Or just use the black ink as the deciding factor regarding placement. Does it matter how the inks are printed...alot of press shops use KCMY. Dot gain would be the big think here...yellow being last as it is the least important. Oh, and would you scan in CMYK or RGB. I always scan in supersampled RGB for most everything.

Excellent tip about blurring colours independently of luminosity. (which for other folks means blurring the *a and *b channel in Lab colour mode.)