How do you remove picture artifacts like these?

[fischermx]

On this address http://fischermx.bravehost.com/ I have an amplified (200%) version of the picture I need to correct.

This picture is a scan from a magazine, at 300dpi, with all neutral settings.

As you should see, the picture have a lot of little squares, they are less visible at 100% zoom, but I still see it and they are annoying.

The scanner (HP G4050) software has nice option "Descreen" which helped to get ride of this noise like by 50%. (The sample posted was not scanned using that feature).

In Photoshop, the Blur tool seems to make a good job if I manually retouch the picture, but that's a very painful process, I'm gonna scan a lot of picture and it would take a lot of time.

In Corel PaintShopPro, there's a sort filter called "Salt and Peper" remover that together with "Skin" smoothing, somehow fixed it, but not enough to my sight.

How do you recommend me to fix this?

BTW, these squares are not visible on the magazine at all, just if you see it with a magnifying glass.

[tatertot1010]

Do you have Photoshop? It has Filter>Noise>Reduce Noise. You can set it to remove JPG artifact, and play with the settings. It'll help, but there's not much you can really do when you scan from printed media, besides hand-touchups.

[NogDog]

You might get some improvement if you experiment with rotating the page on the scanner by various amounts, to see if you can find an angle where the direction of the color dot rows on the photo do not create "interference patterns" with the pixel rows of the scanner.

[fischermx]

tatertot:

Thanks a lot, I didn't know it was there. It was as great as the one in PaintShopPro.

NogDog:
Thanks for this advise. Actually I got some improvement by simply moving the magazine a couple of milimeters in the scan surface. It reduced the amount of burls on the picture.

[fischermx]

tatertot:

Actually, it is the Dust and Scratches filter the one who works like a charm in this case. The plain Noise Filter still lets too much of the noise there.

But I can't find a one-click Skin Smoothing filter as the one in PaintShop. How do I do that in PhotoShop ?

BTW, what's the best format to keep the picture if I want/need to do some retouching in PhotoShop and other in PaintShop ?

[Mr.X]

check this out - http://img104.imageshack.us/my.php?image=facedu2.jpg
i made them disappear :cool:

[Mr.X]

When scanning there is no way to remove the squares cause they are not on the picture actually. These little squares are on the paper used for the magazine. You see different papers have different qualities, thickness and surface. That is why you have these little ones on there.

I guess I got carried away with the filters I used, but these dreaded squares are gone, right. And it is a piece of cake to do this. No special skill required, no nothing.

Wanna hear what the deal is all about?

[fischermx]

Yes, please let us know ! :)

BTW, those lines are not in the picture, but they are not in the magazine either.
They are an artifact created by the scanning itself.

I discovered that because if I scan at 600dpi they are gone and instead, the real dots on the magazine paper appears.
http://img410.imageshack.us/img410/939/realdotsnb3.jpg

[fischermx]

And this is my final try:

http://img383.imageshack.us/img383/6638/skinsmoothag8.jpg

First, scan at 600dpi. Then in photoshop:
1.- Dust and Scratches, 2 pixels radious.
2.- To smooth it more. Reduce noise. Strength:10, Preserve Details 45%, Color Noise 0%, Sharpen 0%.
3.- Then in PaintShopPro, I ran the smooth skin filter at 45%.

I don't know how to do Skin Smooth in Photoshop, I think what I did on step 2, smoothed the skin a little, but it did it for the whole picture.

[WebJoel]

That is quite amazing. I played around with that image for awhile in PaintPro and ended up with something not even half as nice as this end-result. I have PaintPro too (v. 7 I think??), -don't use it much.

[Poxicator]

I've just mentioned this pattern in another thread but I'll explain it a little more here. This is called moire and occurs because print creates images by seperating it into 4 colours (cyan, magenta, yellow and black - CMYK) which are printed by a halftone pattern (dots). The mixture and strength of the four colours creates the full colour printed images we're all familiar with. The halftone pattern creates a series of roses (dots that look like the tudor rose) and are quite visible under a magnifying glass. Halftones are printed in varying sizes, the larger the size the coarser the print. A halftone of 65lpi or 85lpi (newspaper) being the larger dots, 150 or 165 for general print and 200lpi for artprint/fashion having the smaller dots.
When we scan these images the scanner is more accurate than our eye in that it picks up exactly what's printed including the halftone pattern whereas our eye slightly blurs the halftone pattern to produce what seems like flat colours and soft tints. The resulting pattern is referred to as moire and can be difficult to eradicate without blurring. Going by the results above blurring is exactly what's occurred however its been noted that moving the image has given different results. You should experiment with scanning at different lpi eg. 150, 165, 180 & 200 and set the descreening to those levels. This should avoid the moire pattern appearing if you've done it properly and rotating your image could help too. Its much better to attend to the image as its scanned rather than the digital image within your app. However, you may find there's still problems. Within the Noise filters in PS you could try median or guassian blur to help rid you of the pattern and I'd suggest rather than doing so on the whole image you try on the seperate plates of the image to achieve the best results.

A note of caution, if you have moire within your image that will become much worse if you print from that image again!