Software (Version CS3)Learning Software (Version CS3)
A self-guided tutorial by Ross Collins, North Dakota State University.
Lesson Three: Selecting, cutting, cloning, sharpening, gaussian blur, image modes
We're ready to take on some serious business using Photoshop: subtracting things you don't like from an image. Skin blemishes we've already covered: using the Healing Brush tool, simply click the blemish away! Available by prescription! (If only.) We'll put the Healing Brush to more good use here. And then we'll go further. Much further. Recall that photojournalists believe it unethical to remove objects from photos. But graphic artists? Depends, and I'm not opening a discussion on ethics here. I merely supply you with tools. It's your choice what to do with them. (Don't we hear pro-gun people make the same argument? Just saying.)
Save this photo to your desktop. A photojournalism student took this photo of an NDSU Band Day observer a few years ago. Today, of course, we don't allow smokers on campus! Do we? Anyway, Photoshop gives us an opportunity to change history. Here's what we'll do:
I. Remove cigarette.
1. Choose cigarette using a selection tool. (Review Selection tool overview from Photoshop Lesson One) I used the Quick Selection tool, new to CS3: just drag over to select. If the selection needs slight tweaking, try choosing the Lasso tool, hold down the Shift key to add or the Option key to subtract, and drag small circles around affected pixels. You may need to zoom in.
One more zoom alternative: hold down apple key, choose + to zoom in, or - to zoom out.
2. When you've selected the cigarette, Choose Cut from the Edit pulldown. You could paste this cigarette somewhere else (into your favorite politician's nose?) but, really, we want to ditch the butts nowadays, so I'd just skip the paste.
3. Now the hard part: clone the background into the white blob where the cigarette used to be.
4. Smooth the boundary between the face and the cloned area by running the Blur tool or Smudge tool on the edge.
The Clone tool does take some practice, but it's well worth it (see illustration at right).
II. Remove freckles: while I don't think freckles are so bad, some people hate 'em. So to avoid offending anyone, let's just get rid of 'em.
1. Choose the Healing Brush or Spot Healing Brush tool.
2. Sample an area of skin by a freckle (Option-click). If using the Spot Healing brush, you don't have to sample.
3. Click on freckles as necessary to remove (see right illustration).
III. Blur background: This background is distracting. If the photographer had used a telephoto lens or dimmer light, he or she could have blurred the background in camera, but no matter; we can take care of it now. (You also may wish to darken the distracting white area, see Lesson Two.)
1. Choose background area with Quick Selection or other tool.
2. Choose Blur, and Gaussian Blur from Filters pulldown.
3. Change the pixel radius to obtain the effect you want (see ilustration).
4. Soften boundary between blur and face using Blur or Smudge tool.
IV. Sharpen rest of image: The face is slightly fuzzy. You can snap it up fairly well, though, using the Sharpen filter.
1. Choose face area with appropriate tool.
2. Choose Filter, and Unsharp Mask.
3. Sharpen as necessary, based on instructions from Lesson Two.
Random history: Just who was Carl Friedrich Gauss? You ought to know, as he's the only Photoshop tool named after a person.
Modes
Most of the time you'll be working in RGB mode, the default for images from scanners and digital cameras. This is the mode that gives you access to all Photoshop options. But sometimes you'll need something else. Described below are other options.
Grayscale (Choose Mode and Grayscale from the Image pulldown) gives you a black-and-white photo with shades of gray. If your photos will be published in black and white, this is how they'll end up. We noted black and white is much cheaper to print than color, so it's still a popular mode.
Duotone adds a spot color to a black and white picture, with a toning effect. This is a good option to snap up black-and-white photos while still avoiding the cost of process color.
To make a duotone (or mono, or tri, or quad) you need to first Grayscale your photo. Then
Note: Duotones must be saved as EPS files to use the spot colors. Otherwise they may default to CMYK.
CMYK is necessary for final adjustments before printing, as printers use these inks (Cyan-Magenta-Yellow-Black) to print full color photos. (Computers and televisions use the RGB, Red-Green-Blue, color generation process.) Graphic artists normally do all their work in the RGB mode, then convert to CMYK just before sending to a printer. Usually you need to ask the printer first for specifications she needs for the conversion.
Seldom-used modes
Index color reduces the range of possible colors to 256 based on a Color Look-Up Table. This optimizes the image for faster web display, but is seldom an issue for graphic artists.
Bitmap (see illustration at right) reduces the image to only black or white (line art), so few of Photoshop tools can be applied (Choose Grayscale before Bitmap).
LAB color (Lightness, A channel, B channel) is significant to high-end printers, but not usually part of everyday printing.
Multichannel mode supports spot colors.
Quick tip! Straightening a horizon line.