Computer Graphics with Photoshop - Removing shadows in portrait

Author

Removing shadows in portrait - ( method using CHANNELS ???)

Pat

2004-01-20, 11:28 pm

Hi,

I would greatly appreciate your help on the following question.

I have some portrait pictures with shadow on the wall (background)
caused by the camera flash. I would like to remove the shadows.

While searching in this group and on internet, I understand that there
are various methods to get rid of shadow.

I understand that removing shadows using channels is one of the good
methods. Could you please explain this method?

Here's what I found on internet - but not sure how to do it.

"there is a method using CHANNELS to exactly match a discouloured
portion of an image to its surrounds. it is primarily used to remove
stains such as wine stains from photos, but i have used the technique
many times to remove shadows from portrait shots, matching the skin
tones in the shadows to those surrounding the shadowed portion. i dont
have enough internet time at the moment (not on my computer) to go
through the entire technique, but a cursory search of tutorials on the
net should help you find the technique, as it has been shared by the
adobe programmers. the critical point being, that channels are used to
correct this, not burning or dodging or contrast masks or anything
else, which will give u sub-standard results compared to the channels
technique."

Thanks,
Pat

Mike Russell

2004-01-29, 4:28 am

Pat wrote:

quote:

> Hi,
>
> I would greatly appreciate your help on the following question.
>
> I have some portrait pictures with shadow on the wall (background)
> caused by the camera flash. I would like to remove the shadows.
>
> While searching in this group and on internet, I understand that there
> are various methods to get rid of shadow.
>
> I understand that removing shadows using channels is one of the good
> methods. Could you please explain this method?
>
> Here's what I found on internet - but not sure how to do it.
>
> "there is a method using CHANNELS to exactly match a discouloured
> portion of an image to its surrounds. it is primarily used to remove
> stains such as wine stains from photos, but i have used the technique
> many times to remove shadows from portrait shots, matching the skin
> tones in the shadows to those surrounding the shadowed portion. i dont
> have enough internet time at the moment (not on my computer) to go
> through the entire technique, but a cursory search of tutorials on the
> net should help you find the technique, as it has been shared by the
> adobe programmers. the critical point being, that channels are used to
> correct this, not burning or dodging or contrast masks or anything
> else, which will give u sub-standard results compared to the channels
> technique."

Why not put up a copy of the image and see what people will do with it. We
love a challenge.

Meantime, apologizing for my brevity, this may be helpful: using a contrast
enhanced copy of the "a" or "b" channel from Lab mode as a selection or
layer mask may save work in either cloning out the shadows or using curves
to lighten the background generally. This will be most effective if the
wall color differs from the people or objects that are casting the shadow:

--

Mike Russell
www.curvemeister.com
www.geigy.2y.net