Identifying altered images

So i have some images and im trying to identify if they have been altered, some retouching i think to accentuate some parts of the image and some slight alteration in other areas

can anyone shed some light on what i should be looking for and if there is anyway to tell if they have indeed been altered ?

cheers

hi,
first i am novice... so i don't know all the ways but a few things i look at...

the picture itself.... may give me clues..... for example a missing shadow or a shadow that not right... one example there was this award winning picture... and a nauralist noticed the animals were too calm.. that was enough suspicion to look more closely and it turn out the picture was photoshopped..!!

a lot of time i'll zoom in (down to seeing the individual pixels) on a picture and look for flaws... for example
looking for halows, result of smoothing out and disturbing the pixals, around a object. but i do have to keep in mind that some cameras will induce a halow sometimes.. another thing i look for is the consistency of the color pixals... acrross the picture.... looking for disturbances...
recently just looking at a picture on the face of it was good and look relistice... zooming i saw halows around the main objects and also notice a line about 1 pixal wide around the main objects!!

there a lot of articles on fake/modified images.... on the net a simple search will find them... this one I found for you , you might be interested in .
http://spie.org/x16032.xml

I hope it was of some help.....

now this is a fun site... i go to to it just to enjoy,,, but also i use to help me train my eyes... on spotting flaws and mistake to avoid in retouching.... it may be informative for you.... http://photoshopdisasters.blogspot.com/

donpablo said:

So i have some images and im trying to identify if they have been altered, some retouching i think to accentuate some parts of the image and some slight alteration in other areas

can anyone shed some light on what i should be looking for and if there is anyway to tell if they have indeed been altered ?

cheers