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Robert D Feinman

A Workflow for Inkjet Prints

Most of the Photoshop printed material has, until recently, been aimed at producing files that will be sent to a printer and reproduced as half-tones. The recent availability of high-quality inkjet printers requires changes to these procedures for the person making his own prints.
The steps here are designed to help make the printed page look as close to the screen as possible and take some of the confusion out of color management and image sizing.

The first step is to obtain an ICC profile for your scanner or digital camera. You can use a commercial product such as Monaco EZ-Color to make your own or obtain one from the manufacturer. Without this information all the remaining steps will be much more difficult.
The second is to set up your monitor using the Adobe Gamma tool or a similar utility.
The steps below assume you are scanning a transparency;  you will have to make some adjustments if you are starting with a digital camera image.

original
Original image from scanner 

The first step is to set up the scanner so that all of the image detail is captured. Place a piece of clear film and a piece of fully exposed film in the scanner and note the highlight and shadow settings that produce a full-range of values. Use these settings for every slide rather than the automatic values the software may try to use. If you have a profile for the scanner you must use the values that were set when the profile was created. In this example, the shadow is set to 1 and the highlight to 191. Since we will make all adjustments in Photoshop there is no need for expensive scanning software. Any adjustments made by the scanning software is done on the pixel values after they are captured by the scanner. This is exactly the same as what is done in Photoshop or another editing program.

Exposure Settings
Scanner Density Settings 
Next set the resolution to the maximum optical resolution that the scanner provides (this model is 1600 dpi) and set the size to 100%. We will make all the adjustments after the image is brought into Photoshop. This avoids resampling by the scanning software.
Also set the bit depth to the maximum your scanner allows (this model is 12 bits/color or 36-bit image).
We are trying to capture every bit of information that we can so we will have the most flexibility when editing the image.
You can make an exception to using the maximum scanning resolution if you are certain that you are not going to enlarge to the limits. The rule for most inkjets is to aim for 300dpi in the final image so a 35mm film scanned at 3000x2000 would yield a 10x6.7 inch print.
On the other hand a 4000dpi scan of a 4x5" slide will yield an image capable of a 13x enlargement. Since a 16x20" image is only a 4x enlargement there is little value in using such high resolution in the scanner. I have found no difference between resampling in the scanner software or afterward in Photoshop.
Some users of digital cameras are satisfied with output in the 200 to 240dpi range.

Size settings
Scanner  Image Size Settings 


This is an image of a church in North Adams, Mass. It was taken with a medium format camera on Ektachrome 100 using a polarizing filter. Notice the darkening in the corners caused by the use of the filter on a wide angle lens. The use of the polarizer is what produces the dark sky. Since the image was taken from across the street there is too much foreground.
The unprocessed image is too magenta, the result of the way this scanner processes the film.

Untagged scan
Image after scanning without profile

The first step in Photoshop is assign the scanner profile. This is found under menu Image->Mode->Assign Profile. Pick the profile for your camera or scanner as established before. Notice that the colors have shifted towards the green and the most of the magenta bias is gone. The image is also somewhat darker. This is close to what the slide looks like, but we still have to take into account the effects of the printer.

after perspective transform
I
mage after scanning with profile assigned

Unlike most advice on workflow, I advocate using the unsharp mask as the next step. The unsharp mask makes light tones lighter and dark tones darker, so that if we push these too far with brightness adjustments later in the process and then sharpen, we run the risk of clipping the values. 

Prior workflow advice assumed that the final output would be to a printing press and thus the sharpening was done near the end to compensate for losses in the half-tone process. Inkjet printers can produce much finer detail than a printing press so we won't need to compensate for press losses.
I have masked off the sky so that I won't sharpen it. See my other tips on optimizing sharpening.

Masked sky
Quick Mask of sky

Here is the unsharp mask dialog box. We want to choose a radius so that the physical size is about 1/100 inch. This would be in the range of 2 to 3 pixels (3 pixels /300dpi). Because of the bright window trim I chose a value toward the low end so as not to produce halos around the window frames. The threshold is set to avoid sharpening the noise. I usually use a value of 7, but this image has a lot of low contrast grays so I lowered it to 4 to enhance the roof detail. I find an Amount of 150 to 170 is usually correct. The unsharp mask will not be applied to the sky and the edge of the building.


sharpening settings
Unsharp mask settings
To show that the unsharp mask alters the overall color range compare these two histograms. One histogram is from before the unsharp mask and one after. Notice the change in the height of the peaks in the highlight and shadow region regions.
Since we don't have any values at 0 or 255 yet we will not having clipping from the unsharp mask step.

unsharpened histogram
sharpened histogram
Unsharp histogram vs sharpened histogram
The next step is to fix any remaining brightness and color issues. I find using the curves tool the best for almost every adjustment. Here is the curve I applied to the image to brighten the dark and midtone areas slightly.

Overall adjustment
Overall brightness adjustment
This is the image after the curve shown above was applied. In order to maintain the dramatic look we have not brightened as much as possible so there are practically no full white areas.

After overall adjustement
The curves effect applied
The dark greens of the trees are lacking in detail so we will treat these next.
Using the selective color tool we select the dark greens. Here is the selection shown as a quick mask. Notice that not all of the tree area is fully selected. We don't want the effect to be too uniform. See my other tip on how to make selections when editing 16 bit images.

Green mask
Dark green quick mask
Here is the curve for fixing the dark greens. Notice the boost from 52 to 62. Because of the selection, the upper part of the curve will not do anything since there are no bright pixels selected.
Dark green curve
Dark green curve

Here is the image with the dark green opened up a little.
Until now we have been making adjustments without regard to the output. In order to fine tune the image for the intended use we must now switch to preview mode.
Along with the scanner profile and the monitor adjustment we need a series of profiles for the printer, ink and paper combination we are planning to use. Once again it is possible to create these yourself or to get ones that are close to your print conditions. Ideally you want to have a profile made for each combination of paper and ink you plan to use on your model printer.

After dark green boost
Image with boosted greens

Turn on preview mode: View->Proof setup->specific paper. You can toggle between preview on and off with Control-Y. This paper preview shows that the image will be printed lighter and with more contrast that the screen image indicates.
We will continue all the following steps with the preview turned on. We are "targeting" the image for our specific output device.

Preview mode turned on
Same image with print preview on

As shown in one of my other tips, fixing "leaning building syndrome" is one of the ways to make architectural pictures more professional looking. Here is the image while using the perspective tool. We have added some guide lines to make it easier to check for parallel vertical lines.
Before this step we converted from 16 bit to 8 bit mode so that we can use this tool. From this point on we will try to limit the amount of image correction that is done so as to avoid posterization of the image caused by quantization errors when adjusting RGB values.  

fix perspective
Fixing perspective
Remember we have done all prior editing in 16 bit/color mode. Notice that the file size is now  43.5M and the image size is still as it was when we scanned it in at 100%. When the image was in 16 bit mode the file size was 87M.
Original image size
Original image size
To aid in cropping/sizing we change the image resolution to 300dpi without resampling image. This changes the document size values without altering any of the image data. We are trying to avoid lossy changes as much as possible. The image will now print at about 11x14 inches. This new size will allow us to visualize the final size when cropping the image.
resized image
Resized image size

While cropping we can look at the info palette to keep an eye on the image size. The W and H indicators show the cropped size in the current units.
crop info
Info palette during crop
We are removing most of the street which we had to include since we photographed the church from across the street. The nominal image is now about 12"x11.5".

crop preview
Crop preview during crop
Now that we are viewing the image with the printer preview on we find that the contrast is a little too low and the blacks and whites are not as intense as they might be. We add a curves layer which spreads the values out to compensate for the printer characteristics.
printer adjustment curve
Printer adjustment
Another change we wish to make is to remove some of the excess blue in the shadow side of the church. While shadows are supposed to be bluish, this film exaggerates the effect. We made a selection of the shadows, shown here in quick mask mode. We then added another curves layer to lower the value of the blues. See my other tip on how to do this in detail.
shadow wall mask
Shadows quick mask
Here is the layers palette showing the overall curve and the shadows curves. In principal we could have made these changes in 16 bit mode using the selection tricks mentioned in my other tip, but by using layers we can alter the amount of the effect and see how the multiple layers interact. In addition, if we need to use this image for another purpose later, we can turn these layers off and target the image for the new purpose.
final layers
Final layers palette
Here is the final image just prior to printing. We now make one more adjustment to image size to set it for printing.
x
Final Image
We want to print this image on 8½x11 inch paper. So we resize the image to a width of 8 inches. We don't resample so the resolution goes up. This way we have not thrown away any data. We are sending too much data to the printer, but it will be resampled down to the printer's preferred resolution. This slows down the printing slightly, but we have limited our resizing to just a single step from scan to print.
printer size adjustment
Image size for printing

Here is the print dialog showing the print preview. Note that Photoshop does not color manage this dialog so don't pay any attention to how the dark the image appears, just its placement.
The important issue is to not use any color management in the printer. Since we have edited the file with the print preview on we don't want any adjustments added during the printing step.
Also note that the document is still tagged with the scanner profile, so we have avoided any data loss by converting from one profile space to another. If you think you will need to use this file again make sure to save it with the profile attached.

print dialog
Print dialog
To summarize the main points:
1. Scan at max resolution and 100%.
2. Capture all data at highest bit depth.
3. Apply profile for scanner or camera.
4. Sharpen select areas.
5. Adjust brightness, contrast and density.
6. Fix problem areas or colors.
7. Fix perspective, if necessary
8. Crop as needed
9. Add layers to enhance image while viewing in preview mode.
10. Resize to print size without resampling.
11. Print without printer color management.

For reference the two images are shown again, below.
Most of the changes on this image are relatively subtle.
It is the small changes that change a snapshot into a picture
that reflects your artistic intentions.
Nothing was done except to compensate for the failures of
the recording and reproducing media.
You are, of course, free to make deliberate distortions if that
is your goal.
For the frugal all changes were made without purchasing any
extra scanner software or fancy plugins.

original image
final image
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© 2003 Robert D Feinman