View Full Version : Finding middle gray


lagaret
04-26-2004, 12:32 PM
I'm trying to find middle gray in an image. I know that I can find highlights and shadows using threshold. But is there a way, WITHOUT guessing visually, to find a middle tone in images color or b/w? I have some difficulty with tones so I'm a little hindered there.

I've tried selecting color range and picking middle tones but that is not working. I've tried setting the color info pallette set to gray tones and tried to find middle tones in the image by watching the amount of blacks in the pallette. Not working.

At this point I'll begin to use a Color Checker chart when initially taking the photograph but I'd like to improve the quality of my older images.

If anyone can help with suggestions, links, tutorials or what ever comes to mind I would be truly indebted.

Thank you in advance!

:eek:

Doug Nelson
04-26-2004, 12:47 PM
Are you talking about finding 128,128,128 in an existing image, or are you wanting to find something that should ideally be middle gray but isn't? In the former, you can simply look at the threshold line when it's set to 128, or if you want something more permanent make a layer filled with a contrasting color and set the Underlying Layer BlendIf to 127 and 129 (I found this to be very restrictive, though, and opened it up to 120-130).

In the latter, find something that in the real world should be neutral gray and click on it with the midtone eyedropper in the curves or levels dialog. Or, more precisely, add a curve point and then use the up/down arrows to make it 128,128,128.

Or just do what I do and move the eyedropper around while watching the info palette in grayscale mode until you find something that's close to 50%K.

lagaret
04-26-2004, 01:11 PM
I'll all of the methods you mentioned, thank you. I think the most efficient one so far is just using the eye dropper tool to find 50% gray. Thanks again!