Photoshop Elements 2022 For Dummies. Barbara Obermeier

Скачать книгу

(*.tif, *.tiff)

      TIFF (Tagged Image File Format) is the most common format used by graphic designers. TIFF is generally used for importing images in professional layout programs, such as Adobe InDesign and QuarkXPress, and when commercial photo labs and print shops use equipment that supports downloading TIFF files directly to their devices. (Note: Direct downloads are used in lieu of opening a Print dialog box.)

      Inasmuch as creative professionals have used TIFF for so long, a better choice for designers using a program such as Adobe InDesign is to save in the native Photoshop PSD file format. This requires a creative professional to save only one file in native format without bothering to save both native and TIFF formats.

TIFF, along with Photoshop PSD and Photoshop PDF, supports saving layered files and works in all color modes. When you save in TIFF, you can also compress files in several different compression schemes, but compression with TIFF files doesn’t lose data unless you choose a JPEG compression.

      When you choose TIFF from the Format drop-down list and click Save in the Save/Save As dialog box, the TIFF Options dialog box opens. Your options for image compression include

       NONE: Selecting this option results in no compression. You use this option when sending files to creative professionals for creating layouts in programs such as Adobe InDesign. (None of the three compression schemes listed next is recommended for printing files to commercial printing devices.)

       LZW: This lossless compression scheme results in much lower file sizes without destroying data.

       ZIP: ZIP is also a lossless compression scheme. You can favor ZIP compression over LZW when you have large areas of the same color in an image.

       JPEG: JPEG is lossy and results in the smallest file sizes. Use JPEG here the same as when you apply JPEG compression with files saved in the JPEG format.

      Leave the remaining items in the dialog box at defaults and click OK to save the image.

Getting Familiar with Color

      In this section, you find some fundamental principles to make your work in Elements easier when you’re editing color images.

      

Your first level of understanding color is to understand what RGB is and how it works. RGB stands for red, green, and blue. These are the primary colors in the computer world. Forget about what you know about primary colors in an analog world; computers see primary colors as RGB. RGB color is divided into color channels. Although you can’t see the individual channels in Elements, you still need to understand just a little about color channels.

When you see a color pixel (a tiny square), the color is represented as different levels of gray in each channel. This may sound confusing at first, but stay with us for just a minute. When you have a color channel, such as the red channel, and you let all light pass through the channel, you end up with a bright red. If you screen that light a little with a gray filter, you let less light pass through, thereby diluting the red color. This is how channels work. Individually, they all use different levels of gray that permit up to 256 levels of light to pass through them. When you change the intensity of light in the different channels, you ultimately change the color.

      Each channel can have up to 256 levels of gray that mask out light. The total number of possibilities for creating color in an RGB model is achieved by multiplying the values for each channel (256 × 256 × 256). The result is more than 16.7 million; that’s the total number of colors a computer monitor can display in RGB color.

This is all well and good as far as theory goes, but what does that mean in practical terms? Actually, you see some of this information in Elements’ tools and dialog boxes. As an experiment, open a file in Elements and choose Enhance ⇒ Adjust Lighting ⇒ Levels; the Levels dialog box shown in Figure 2-5 opens.

      FIGURE 2-5: The Levels dialog box.

      Notice that the Channel drop-down list shows you Red, Green, and Blue as individual channels, as well as a composite RGB selection. Furthermore, the Output Levels area shows you values ranging from 0 on the left to 255 on the right. Considering that 0 is a number, you have a total of 256 different levels of gray.

      

What’s important is that you know that your work in color is related to RGB images that comprise three different channels. There are 256 levels of gray that can let through or hold back light and change brightness values and color. See Chapters 10 and 11 for more on using tools, such as levels, to adjust color in this way.

Getting Color Right

      In Elements, when it comes to color, the challenge isn’t understanding color theory or definitions, but rather matching the RGB color you see on your computer monitor as closely as possible to your output. Output can be a printout from a color printer or a screen view on a web page.

      We say match “as closely as possible” because you can’t expect to achieve an exact match. You have far too many printer and monitor variables to deal with. However, if you properly manage color, you can get a very close match.

      To match color between your monitor and your output, you need to first calibrate your monitor and then choose a color workspace profile. In the following sections, you can find all the details.

      Color the easy way

      

The upcoming sections are complex and require some dedicated effort to follow the descriptions. If you’re interested in sharing photos only onscreen (that is, on your own website or on Instagram, Facebook, Twitter, and so on) and you plan to leave the printing to others, you don’t need to bother with color correction and going through a maze of steps to get the color perfected. In that case, you can skip the technical stuff in the following sections.

      Your only consideration for onscreen viewing is your overall monitor brightness. If your monitor displays images darker or lighter than other computers viewing your images, you need to follow the upcoming sections and understand how to adjust your overall monitor brightness.

      Calibrating your monitor

      

Your monitor needs to be calibrated to adjust the gamma and brightness; correct any color tints or colorcasts; and generally get your monitor to display, as precisely as possible, accurate colors on your output. You can choose among a few tools to adjust monitor brightness. These tools range from a low-cost hardware device that sells for less than $100 to expensive calibration equipment for $3,000 or more.

      Gamma is the brightness of midlevel tones in an image. In technical terms, gamma is a parameter that describes

Скачать книгу