Greens appear purplish in digital photos - Canon Powershot SD 1100

July 3, 2009 3:11 PM

In a recent batch of digital photos, all the greens (grass, leaves, etc.) came out purplish or really purple. 1. What camera setting can I change to prevent this? And 2. what can I do in Photoshop to correct this?

My wife has a Canon Powershot SD1100 IS Digital ELPH camera. When we downloaded the pictures from a recent shoot all (or actually some of) the greens were purple or purplish.
Have we set the color swap on and how can we get it off?
More importantly, how can I correct this in Photoshop CS2?

You can see some of the photos here

posted by feelinggood to media & arts (15 comments total)

Have you dropped the camera? I bought a camera on eBay because it did the exact things yours is doing (although mine is to a greater degree which makes me happy) with a messed up sensor.
posted by theichibun at 3:33 PM on July 3, 2009

Could it be this sensor flaw? My pictures were heavily distorted, not just too purple. Canon fixed / replaced it and it works great now.

A simple color problem can be fixed with white balance correction. But the "part of the lawn is purple" thing is terrible, and I'm guessing it can't be fixed in simple post processing.
posted by Nelson at 3:39 PM on July 3, 2009

I use Gimp rather than PS but the ideas are the same.

Firstly I would try changing the hue of the area in question. Select the area that is discoloured using the path tool (poss called pen tool in PS?). Then open the hue, saturation and balance dialog/tool. By changing the hue you can make the purple go green.

Another thing I would try if that didn't work would be to use the curves tool to alter the RGB colour channels. I seem to remember you can find Youtube tutorials that deal with correcting colour cast to help solve this. Colour cast isn't your problem but the solution is helpful.
posted by man down under at 3:42 PM on July 3, 2009

Looks like a palette rotation or hue adjustment to me. As for the camera, see if there's a factory reset in the settings menus.
posted by rhizome at 3:54 PM on July 3, 2009

Canon cameras actually have a mode that looks like that. At least the G9 does. I don't have mine handy but it's one of the "art" effects -- are you sure they aren't on?
posted by The Bellman at 4:26 PM on July 3, 2009

It almost looks like an infrared effect: I'd second The Bellman's recommendation.
posted by pjern at 4:59 PM on July 3, 2009

This happened on my camera when I had inadvertently left the nighttime shooting mode setting on. A whole bunch of photos had purply-green grass and bluey white shades. See if there are any exposure settings that may have been left set.
posted by Susurration at 6:42 PM on July 3, 2009

Looks very similar to standard SCN ColorSwap with default settings; here's some random vegetation with and without color swap.

At least on my PowerShots, just setting the camera to AUTO will turn that filter off.
posted by effbot at 3:15 AM on July 4, 2009

I've reset all the settings and it's not doing that any more. Thanks.
Any more suggestions about how to correct the already-taken photos?
Thanks again.
posted by feelinggood at 9:55 AM on July 4, 2009

If all else fails, you could desaturate your photos in photoshop etc, leaving you with black & white photos.
posted by fings at 12:07 PM on July 4, 2009

Any more suggestions about how to correct the already-taken photos?

You could select via color range, grow the selection, refine edge, and either play with the channel mixer (Image, Adjustments, Channel Mixer) or Variations (Image, Adjustments, Variations) and add more green and yellow. Then use the eraser to clean up.
posted by LuckySeven~ at 3:10 AM on July 5, 2009

If you are using Windows, try downloading the free trial of Paintshop Pro X. I use this program all the time (I have a full copy of Version 8). Or you can get a free trial of Paintshop Pro Version X2 if you're willing to give Corel your email address ...
In my version of the software, I removed the color cast automatically. I selected:
Adjust (Menu) | Color Balance | Automatic Color Balance,
then
Adjust (menu) | Brightness and Contrast | Automatic Contrast Enhancement.
If you're picky, you can manually adjust the brightness, then run it through the Automatic Color Balance adjustment one more time to perfect the color tint that you prefer. There are lots of manual adjustments that you can apply (in the Adjust menu) if you don't like the results of the automatic adjustments.
I love this program. It is $99 for the full version, but I use this regularly for photo editing, red-eye removal, image cropping, resizing/resampling (for web images), etc. It is one of my most used apps, even though I am not doing anything very clever with it ... :-)
posted by Susurration at 11:20 AM on July 6, 2009

Correction - it is $42 for the full version at Amazon.
posted by Susurration at 11:22 AM on July 6, 2009

Took another look at this. As rhizome said, it's a palette rotation. I sorry, I don't know Photoshop, but under Gimp 2.6 it's Color->Map->Rotate Colors

I played with it for 5 minutes, on a couple of your photos, and have MeFi mailed you links to the results; not great, but better than what you currently have. I think you can salvage some of them.
posted by fings at 2:43 PM on July 6, 2009

@Susurration: I downloaded a copy of Paintshop Pro X, but it has no automatic option in either the Color Balance options or the Brightness and Contrast options. It is version 10.03.
posted by feelinggood at 3:02 PM on July 6, 2009