Learning Software (Version CS3)

A self-guided tutorial by Ross Collins, North Dakota State University

Lesson Six: layers, red eye removal, improving skin tones.

I. Layers
We've been making a shocking carnage with our images, mucking about perhaps a desperate level of hopeless degradation, after which only a thorough cleansing (choose Revert under File menu, or History Palette) can bring us back to some sort of pristine original. Better would it not be to muck about on a crystal sheet of acetate hovering above our image? Messy failings can merely be whisked away, and the original image remains unsullied. Such is the principle of layers, as noted in Lesson Five. Let's delve further here.

Geezer note: Some of us remember in grade school those serious-minded books describing "the human body," in which several layers of plastic with important bones, glands, organs, hair and zits could be superimposed on layers one at a time to complete the whole lurid picture. Similarly, we can set up layers collect strange bits of pictures into one composite image, or work with one detail of an image without disturbing others.

1. Save these practice images from the Photoshop practice photos file: Limerick.jpg; Clubmoss.jpg; Dijon.jpg.

2. Open Limerick, then Clubmoss. Set them up side-by-side on your monitor so you can work between them. The plan is to copy and paste that bearded Irish stone head into the moss--and make it ghostly. (Illustration on right. Vaguely ghostly, no?)

3. Zoom in on head image so that you can accurately select the head with the Lasso tool or Quick Selection tool.

Remember: To add or subtract pixels from your selection for a perfect copy, hold down the Option key (to subtract) or Shift Key (to add), and circle with the Lasso tool or drag with the Quick Selection tool what you want to add or delete.

From the option bar at top, choose Refine Edge and Feather, and about 5 pixels. This gives you a softer blend between images.

4. Zoom back out so that both images are at 100 percent screen view size. This gives you an idea of how well your head will fit into the moss. As you can see, it's a little small. Using the Image Size command, chop pixels off your club moss (make the image smaller) until the result looks more in perspective to the head.

5. To move the head, choose Copy and Paste, Cut and Paste, or just Drag and Drop from one image to the other using the Move Tool (upper right corner). If it's not precisely placed, use the arrow keys to nudge pixel by pixel. (Note that Copy and Paste keeps your original image intact, which you usually want.)

6. Likely the head will be a bit big or small. From the Edit menu, choose Transform and Scale. Try Warp also to add a more spirit-like look. Note that dragging to enlarge can pixellate your image, so use this feature sparingly. Double-click on the image (or Return key) to accept the changes.

7. Under Window pulldown, choose Show Layers (if the Layers palette isn't already open). Yep, the head's a new layer all right, likely called Layer 1. The layer you're currently working on will be highlighted. You can move or change anything on this layer without affecting the rest of the image. Click to choose other layers to work on. The palette will always show a background layer. The eye means the layer is visible--to make it temporarily invisible, toggle off at the eye. Layers are displayed on the palette in the order they appear on your image--top in the palette is top in the image.

Note: You can't work on a layer that's not highlighted in the palette--the droll failing of drippy debutantes, which you're not. Right?

Choose Layer Properties from the flyout menu on the Layers palette. Name the layer something nifty like "ghostly man," if you want. In the Layers palette choose Opacity of about 60 percent. See how the head looks, well, slightly more ghostly.

10. Cool, yes, but could be cooler. On the Layers palette, scroll down the blend mode options menu (Normal is shown), and select Multiply. This burns your image into other layers, giving you a darker version. To blend into a lighter version, choose Screen (see illustration). You may have to increase Opacity to see the effect. Or, for something completely eerie, choose Difference. This gives you a negative version of an image. Note: you can't apply more than one blend mode at a time, though you can mix blends and opacity.

11. You can paint inside a selection without first having to carefully marquee around it, by toggling on the first Lock option, Lock Transparent Pixels, in the Layers palette. This limits your painting to only the image area, like spreading glue on a spot, then spreading the glitter. Except that was a lot messier, made Mom mad, and therefore was a lot more fun. (See painted yellow hat on illustration.)

12. Wait! Not done yet. These Dali-esque images take time, you know.

Don't know who Salvador Dali was? Check this out.

Open Dijon.jpg, a rather ghostly street in the medieval French town which gave the world the yellow condiment.

Geezer's full disclosure: I lived there for six months. Don't ask me about mustard.

Maybe we could enhance our composite by adding a sort of dungeon from which Monsieur Creepée could emerge into the club moss forest. The window and lamp at the left of look fairly dungeon-esque. First reduce the image size to a better fitting dungeon lair. Then marquee and copy. Paste into the composite image.

13. Change opacity or blends on this new layer as necessary for better effect.

14. Those are pretty hard edges on the right of the "dungeon"-- doesn't blend well. Try choosing the Eraser, Airbrush Mode, and Opacity at about 20 percent. Erase the hard edges. Or try the Smudge or Blur tool. You're the artist, after all, not me. So why am I choosing your tools for you?

Note: This layer thing can be done just about to infinity--up to 8,000 layers. However, layers hog computer memory. You don't have enough for 8,000 layers, believe me. Or even 1,000. Or, in an NDSU cluster, even three. Or so it seems, sometimes.

15. You can save this as a Photoshop document, and preserve your layers. If you save it in most other formats, the layers flatten. After saving as a Photoshop document, you can save a copy as a jpg (or other format), the automatic choice using the Save As... command.

16. Working with many layers creates large files and can slow down your computer operation. You may wish to merge layers to speed things up. To do so, hide all layers you don't want to merge by toggling off the eyeball in the Layers Palette. Then, from Layers pull-down menu, choose Merge Visible. Or choose Flatten Image if you want to get rid of all the layers for good, but that'll be the end to your fun and games with separate body parts.

II. Fixing the dreaded red
Of the sundry problems the amateur's point-and-shoot photo leaves for the hapless Photoshop pixel-pusher to fix is called red eye. That is, pupils of people's eyes look an ugly red, or pink.

Egghead's note: This happens, in case you're interested in the vaguely disconcerting explanation, because when the light is dim pupils dilate so that we can see better--like a camera lens aperture "wide open." Unfortunately, that leaves our retinas wide open to invasion of a brief burst of intensely bright flash. We victims blink and wait to get our sight back after that mean trick temporarily blinds us (hey, says the eye, the light was supposed to be dim!). The flash has actually reflected off the blood-engorged back of our retina (that was the disconcerting part), and directly back into the camera. Hence, red eye.

Okay, but how to fix? Used to have to work with the Clone tool, or paint in black pupils. Tricky. Photoshop 7 and later added something called the Color Replacement tool, and now no one will go back. This is sooooooo easy:

1.Download and open this dreadful cropped photo, or another needing attention. Heck, I've seen a pile of 'em in student projects. Choose he Red Eye tool under the Healing Brush in the toolbox.

2. Find the offending eye. Zoom in for a better view.

3. Click the tool on the red eye. Tah-dah, maybe. If you're not satisfied, undo, change pupil size and darken size, keep trying.

Geezer warning: In the future, if I see any red-eye photos in your photos and designs, automatic F! Even if you've already graduated! You can't hide from us old professors, you know.

III. Nipping and tucking
People with slightly reddish, blotchy, pimply skin won't be enthusiastic to see their flaws emphasized in digital photos. Unfortunately, digital systems tend to emphasize these, particularly when the unfortunate is photographed with flash on camera. I don't believe it's lying to soften unflattering skin tones that the unforgiving pixels have made harsher. And here's a fairly easy way to do it. (Based on a tutorial by Lee Varis in Macworld, March 2007).

(Right: original and improved red eye and skin tones.)

1. Download this photo, or a similar one with skin problems. Fix the red eye, using technique above. This man also really needs some work on that reddish skin, although in this case he apparently doesn't have to worry much about acne blemishes. But this technique below works well for people with those problems as well.

2. Open a New Adjustment Layer from the Layer pulldown, Hue/Saturation.

A reminder on Adjustment Layers: While you can make adjustments on the actual picture from the Adjustments options in the Image pulldown, it's safer to make changes on a new Adjustment Layer. If those changes don't work out the way you want, just throw away the layer--drag it to the trash icon in the Layers palette--and start over. Otherwise, you'll have to go back using the History palette.

3. In the Hue/Saturation dialogue box, choose Edit: Reds.

4. Select the left eyedropper (bottom left) if not already. Find a really red area or pimple. Click. Note the gray bar in the color bars at bottom indicates sample area.

5. Now select the minus eyedropper tool, on the right. Click on a nicer-looking area of skin color.

6. To check to see what area of skin will be affected, slide the Hue slider all the way to the left. The cyan areas indicate what part of the image will be changed. If you want to make the affected area less, slide the right corner of the gray bar to the left.

7. Slide the hue slider back to 0, and then over toward the yellow, until the skin looks good.

8. Move the Lightness slider a little to the right to get a more uniform skin tone.

(Illustration right: the hue/saturation dialogue box on adjustment layer.)

9. If some areas are too yellow, clean that up; choose Edit: Yellows. Use eyedropper tool to select area that's too yellow. Then use minus eyedropper tool to select red areas, now cleared to more natural skin tone. Move the hue slider to the right to make yellow areas a little more reddish.

10. Okay to accept. Should be much better! Sometimes lots of pimples, lines or blemishes will still show up a bit darkish. You can lighten them with the dodge tool.