I added two new photos to an iWeb page by dragging them from iPhoto (as I normally do).
Both photos now show a strong interference pattern (reminds me of an old TV picture using an antenna).
I attach an example of part of 1 photo.
Both photos look fine in Preview, Photoshop & iPhoto.
Can anyone suggest how to avoid this problem ?
iMac, Mac OS X (10.6.8)
It's called moiré. You get that when you resize an image that has a pattern. The lines start interfering.
http://en.wikipedia.org/wiki/Moiré_pattern
Resize in an app before adding it to iWeb.
More here (the click images) :
Thank you for your answer, unfortunately I cannot seem to fix the problem.
I tried resizing the photo in Photoshop, making it bigger or smaller, but I still have the problem
in each of the sizes (3 in, or 6 in, or 10 in widths).
I do not have the problem when I rotate the photo sideways, but I do not want to display it this way.
Is there a filter in Photoshop or iPhoto that would fix the problem ?
Do these photos originate in magazines or books? If so they consist of arrangements of tiny dots, and PhotoShop very likely has a 'descreening' filter to remove the interaction patterns which can arise when they are digitised. Slight defocussing can be an alternative. Both methods are likely to soften the detail slightly.
So it isn't in iWeb.
Internet to the rescue :
http://graphicssoft.about.com/cs/photoshop/ht/apsremovemoire.htm
http://photographylife.com/how-to-remove-moire-in-photoshop
http://www.youtube.com/watch?v=k34s2xpYRm8
More if you search for :
avoid moire effect
avoid moire pattern
I am not sure were they originated, but in higher magnification they show faint closely spaced parallel vertical lines. Possibly they were from a newspaper.
The problem only occurs in iWeb
Success!
The first link you gave suggested to apply a Photoshop Noise Median Filter, a Radius Value of 3 worked.
Thank you very much Wyodor.
Interference Pattern on photos in iWeb
