Steve,
Edit – Mode – 16 bit. An open image window (not full screen) shows the bit depth in the title bar.
The Info Palette can show 16 bit numbers. Click on the little triangle in the top right corner of the Info Palette, and select Palette Options.
Rob
Rob,
Thanks, but I know how to know if I am editing 16bit.
And I know how to read the 16b values from the info pallet.
What I am looking for is how to select a 16 bit color from the color pallet?
Also, and more importantly:
1> take a good 16bit grayscale image with fine graduation . . . scanned from a scanner that produces 16bit grayscale.
2> zoom in to 1600% and run your cursor over the pixels and watch the values on the 16b info pallet. Things are looking good as you see values with little delta between pixels.
3> Now add a curves adjustment layer to change the contrast. With little or no change on the curve, observe the posterization by running cursor over the pixels again.
So, the question is, "how can I edit non destructively and get 16 bit results?".
Thanks to all that consider these two questions.
Steven Bland
If you are working in 16 bit, the bar at the top of the image window will have "/16" after the file name; if you are working in 8 bit, you will see "/8". Preceding the slash will be the color mode (e.g., "RGB").
I have no question about what mode or bit depth I am working.
I AM working with 16 bit per channel images and have been for years.
My questions are:
=================
#1 – The color picker is 8 bit per channel, how can I select color at 16 bit per channel color resolution.
#2 – Adding an adjustment layer to a 16bit grayscale image causes the fine graduation provided by 16bit to turn course/posterize.
The advantage of 16bit per channel is fine graduation of tone. That is destroyed by Photoshop when adding an adjustment layer. This is an unacceptable degridation in quality of the data, so I am looking for other alternatives to non-destructively manipulate the data.
Steven Bland
Adding an adjustment layer to a 16bit grayscale image causes the fine graduation provided by 16bit to turn course/posterize
Are you sure you are viewing at 100%? Any other degree of magnification will show banding on a gradient (only on screen, of course, the actual image will not be affected).
Yes, I know when I have moved from one pixel to the next no matter what percent of magnification I am at.
I went back into my 16b grayscale image to reproduce what I was seeing to post some values here. Please accept my apology, as I was unable to reproduce any problem with posterisation associated with adding the adjustment layer.
If you are still willing to look at this after that blunder . . . The question that remains is how to pick color at a 16 bit per color channel (16bpcc) color resolution.
Choose a finely graduated area like the sky.
Double click the foreground color to open the Color Picker. Run the eyedropper over two adjacent pixels that are close in value by looking at the info pallet. Click on each of the two pixels notice the values picked.
Here is an example:
PIXEL A
——–
Info Pallet – K=32526
HSB=180 5 100
RGB=242 255 255
Lab=99 -2 -19
CMYK=5 1 0 0
PIXEL B (be sure to click on pixel B to update color picker data) ——-
Info Pallet – K=32519
HSB=180 5 100
RGB=242 255 255
Lab=99 -2 -19
CMYK=5 1 0 0
See, two different K values result in the color picker selecting the same color.
Next thought is, "hey, maybe the color picker just cant display that much color resolution in the different color models. Perhaps it can pick it, but not display it".
Eyedrop PIXEL A K=32526
Marquee a small area and fill.
Run cursor over the pixels filled and check the value in the info pallet. Notice that it filled with K=32604
Similar limitations exist when working with color images. The color picker only shows 256 shades of each channel R,G,B where we really should be seeing 2^16=65536 shades of each color channel R,G,B.
Conclusion – It appears that while the info pallet is capable of measuring the full color depth of the image, the color resolution of the color picker is inadiquate to select colors at full color resolution.
Some level of 16bit color resolution has been around since at least version 7, about 7 years ago. I am supprised the limitation still exists.
Does this limitation exist in the Extended version for Scientists and Engineers?
Does anyone know if there are any plans to upgrade the color picker to 16bit?
Let me close this one with a thanks to Adobe and the Photoshop development team including architects for taking 16bit color depth as far as they have. I am so greatful for all the capabilities it does provide and am just wanting full access to pixel manipulation.
Steven Bland
Does this limitation exist in the Extended version for Scientists and Engineers?
Steve,
I have investigated this issue:
Is it possible to make a gradient with
PhS’s 16-bit Grayscale resolution ?
Doc New
Px 1000 x 1000
Mode Grayscale
Mode 16 bit
Color Picker:
Foreground R=G=B=0
Background R=G=B=1 >>=>> one unit of 255
Gradient Horizontally
Info Palette
Left Show R,G,B 16 bit
Right Any, e.g. Gray or Lab
Measure R,G,B in Gradient from left to right:
0 1 3 … 131
The stepsize isn’t accurately 1 step in
PhS’s pseudo 16-bit-space (15 bits + 1 step),
maybe because of uncertain mouse movements,
but it’s definitely high resolution.
2^15 / 2^8 = 2^7 = 128
One 8bpc step is equivalent to roundabout
128 15bpc steps. Not accurate (measured 131)
because of PhS’s pseudo 16-bit-coding.
Best regards –Gernot Hoffmann
In the Extended version for Scientists and Engineers,
can I use the color picker to select colors with 16bit per color channel color resolution? Or will I be limited to 8bit per color channel?
8bit = 0-255 on each R G B
16bit = 0-65535 on each R G B
Steven Bland
Steve, have you set the info pane to display color readouts as 16 bit?
Michael,
Yes, have been using the 16bit Info pane since Photoshop CS was released. So we can at least see what we have captured or created using some other device. Why not be able to select that range of colors using the color picker? At a minimum we should be able to select up to 10bits of color depth with the color picker since we know the human eye can see the difference at 10bit.
Steven Bland
