Can I add a RGB 128, 128, 128 as a patch or watermark to measure?

Mack

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Posts: 224

Can I add a RGB 128, 128, 128 as a patch or watermark to measure?

« on: January 26, 2013, 06:52:44 PM »

I sometimes add a small grey 1 inch square (RGB = 128, 128, 128) to an image to help me zero in on the color cast with a ColorMunki Photo.

I there a way to setup QI to maybe add one as a watermark or something easily so I can measure it after the image is printed, and maybe also using the Eyedropper Tool as well in the Editor's window as well before I send it to the printer?

Mack


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Terry-M

The Honourable Metric Mann
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Posts: 3247

Re: Can I add a RGB 128, 128, 128 as a patch or watermark to measure?

« Reply #1 on: January 26, 2013, 07:55:53 PM »

Hi Mack,
Here's how.
First make an image that is alll one colour 128,128,128. You can do this in QU as follows:
Select print to file and set a suitable size page & resolution, say 10x8 at 180ppi and sRGB for web
Make the page colour grey 128,128,128 using the Page Background Colour icon under the page preview.
Add a template so that the page will print.
Click print and save the file with a suitable name and location.
See first attached screen shot
Second:
Add your test image to the queue.
Set the page to Freehand with the 'F' button top right of the page preview.
Go to the folder with grey patch image and make sure no thumbs are selected and the image in the queue is not selected.
Right click and hold until the print properties box appears and select a small size.
Drag the grey patch image to the page preview to where you want it positioned.
You may need to open the page editor bring to grey patch to the front (right mouse click for menu) and re-size and/or re-position.
Print you test iamge with the grey patch.
See 2nd attached screen shot.
Another way to do it would be to make a custom cutout with the grey patch and apply to the test image; that's another story though.
Terry


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Mack

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Posts: 224

Re: Can I add a RGB 128, 128, 128 as a patch or watermark to measure?

« Reply #2 on: January 26, 2013, 08:53:35 PM »

Thanks for the info Terry. I need to digest that all.

Right now, I found I can (sort of) use the border color in QU as it shows it being 128, 128, 128 on screen. The ColorMunki Photo read the printed border it as 120, 126, and 124 so it appears I have a bit of a cyan cast and it needs to squirt some more yellow and magenta ink somewhere (or the ICC profile it wrote is in error?).

I moved the "Custom Colors" (for the borders in QU) up to around 135, 129, 130, and Saved that, and it prints out as a nice 128, 128, 128 now for the border as measured. I will assume the Editor part in QU does not affect the border color in the final print at all, and just the image itself?

So if I add a 128, 128, 128 patch to the image (say in CS6), then any adjustments in QU will only affect the image and not to the border which seems under control now with its own color I added above? If true, then the border color should match the image color patch I add.

If this makes any sense at all...

Also, the sRGB as shown in CM Photo should read as 128, 128, 128 (I'm guessing for a neutral grey.). Would an image saved in "ProPhoto" or "Adobe 1998" saved as 128, 128, 128 be any different in the print vs. a "sRGB" one?

Mack


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Terry-M

The Honourable Metric Mann
Forum Superhero

Posts: 3247

Re: Can I add a RGB 128, 128, 128 as a patch or watermark to measure?

« Reply #3 on: January 26, 2013, 09:22:17 PM »

Using a border seems a good idea.
I'm sure edits to the image do not affect the print border.
The differences in RGB values for a grey you quote seem relatively small. Does thee print look as if t has a cast when viewed in good daylight?
I understood from ColorMunki a publicity video that it was possible to read a section of a printed image, make a target based on those colours and then scan to refine the existing profile. If your profile is not giving neutral greys, then print a grey scale and use that to refine the profile.
Terry


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