View Full Version : Colour Correction


Paulie
08-25-2003, 10:29 AM
Hi, all
My bro has asked me if i can do anything with this photo of him, with the biggest fish he has ever caught. He thinks the flash never went off so as you can see the image has no depth of colour, & the levels are all over the place. I have tried various colour & level adjustments in PS7 but to no avail. Any help would be appreciated.

CJ Swartz
08-25-2003, 03:52 PM
Paulie,

Here's a version using a copy of the Blue channel as a mask in order to separate the portions of the image that need darkening/density added and those that don't.

Make a duplicate layer.

Go to the Channels pallette and make a copy of the Blue Channel (choice of channel to use varies with each image). Using Levels, pull the left pointer far to the right and the right pointer towards the left to create a black/white mask. Be sure to have the Preview button checked in order to see the results as they happen. You are trying for clearcut black/white without grays and without jaggy edges. A slight blur can be applied.

Return to the Layers pallette and select the top layer. Go to the Select menu and choose Load Selection -- choose "blue copy" from the dialogue box.

There are different ways you can proceed from here - you can run a Levels adjustment -- that will affect only those areas not masked, or you can click the Layer Mask button and then change the Layer Blend mode to Multiply -- you'll need to duplicate the layer (with Layer Mask) to bring out more detail.

You can then make color adjustments to the resulting image as you desire. A contrast mask would probably help bring out his face out of the shadows.

CJ Swartz
08-25-2003, 04:27 PM
After adding a contrast mask and using Selective Color adjustments to reduce magenta casts, etc. --

Kevin Connery
08-25-2003, 08:31 PM
It's an unfortunate image, as it's dark, and there's a LOT of noise in the image. If it's from a film camera, scanning the negative would almost certainly give you a much better starting point--probably better than you could get after a lot of Photoshop work.

Assuming the 'original' is lost, and this ia all you have, it's still tricky. Low contrast, noisy images usually benefit from multiply mode adjustments, but that also darkens the image. Screen is good to brighten up images, but also tends to reduce contrast.

What I did:


Curves adjustment layer, set to Screen, and with the highlight point set to around 100--lightening the shadows more than the highlights. (A contrast mask could work, but this is often more flexible.)
Curves adjustment layer, set to Normal, to increasing the contrast in the face--around 85-150 brightness. Couldn't add much without it getting too blocky, and I can't paint, so stopped before that point.
Duplicated flattened image and converted to LAB mode
Apply Image from L channel to Blue channel at 10%, Multiply mode to add contrast.
Ditto for Green Channel and Red.
Hue/Saturation adjustment layer, boosting overall saturation by about 10-15, to counter the loss of color from the previous Applys.
USM at 200%, .5 pixel radius, threshold 20

His face is still low contrast, but any increase caused more posterization than I was willing to accept. Anyone who can paint detail back in could go further and do touching-up, but I'm not a painter/retoucher/drawing person.

Paulie
08-26-2003, 02:47 PM
Thank you both for your great tips. I had another bash myself, just selecting individual parts to adjust, & i think this is the best i'm gonna get!!

CJ Swartz
08-26-2003, 07:52 PM
Looks a lot better, Paulie -- how did you get the detail in the background -- mountains and cloudy sky?

Paulie
08-27-2003, 12:27 AM
Thanks C.J.
I used the clouds filter on a selection of the sky, & the mountains were just hue/saturation, levels & curve adjustments. This result took me about 4 hours to get righ, but as i said previously, i don't think i'm gonna achieve much better!! My bro is pleased anyway!! :-)

Imhotep
08-27-2003, 09:06 AM
Here is another please tell me what you think

Paulie
08-27-2003, 12:36 PM
Imhotep, thats cool! Can you tell me what techniques you used. I thought mine was ok.....after 4 hours work, but i think yours is slightly better than mine :(

Imhotep
08-27-2003, 03:49 PM
Isolated the fish used levels to lighten
Darkened the background again using levels
Color corrected the mountains
color the sky blue and used the clouds filter
it took about 20 minutes

P.S. Thanks for the good critique just starting out your kind words are very encouraging

Imhotep
08-27-2003, 07:14 PM
Hoping to one day soon make a few extra doolars out of it

Flora
08-28-2003, 04:07 PM
Hi!

You all got really great results!

I tried to lift the shadows from the fish using Col's technique which can be found here (http://www.retouchpro.com/forums/showthread.php?s=&postid=54157#post54157) and here is the result: