Photo Restoration - - pixelated photos

margotshp · #1 09-14-2005, 05:53 AM

Does anyone have idea what cause things like this? [ see attached files ]
70% of photos I'm getting to retouch have the same problem

Panpan · #2 09-14-2005, 07:50 AM

Hi Margot.

Can you be more specific about the problem? I see some very slight posterization on some of them, but that could be from jpeg compression and small size. Other than that, they look like details from professional-level images

.

Pierre

margotshp · #3 09-14-2005, 07:55 AM

Hey! Thanks for reply...
I think I talk about posterization.
TIFs and RAWs looks exactly the same, it is not caused by compression

byRo · #4 09-14-2005, 10:47 AM

Margot,

The first thing that strikes me when looking at the images is that they are dark, very dark. This fact in itself can lead to a degree of posterization.....

I took one of the images (the second one, of course

) and opened up the histogram.
In the blue channel 90% of the values are under 64. So what? Well, you are using only 64 different values instead of 256 (for 8-bit work). If you now lighten the photo to full range luminosity, those 64 different values will be occupying a range of 256, but now they will be spaced out 4 by 4. Which is exactly what posterization is!

Why are they so dark?

Rô

margotshp · #5 09-21-2005, 08:24 AM

Hi Ro

Thank you very much for reply.
Yes, I know those images are very dark, that's how I'm getting them from my employer but I thought that maybe I do something wrong... I guess his camera's settings are bad...