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Photoshop CS Bible @Team LiB - Stacy C.

Stacy C. Photoshop CS Bible @Team LiB - Wiley Publishing, 2004. - 773 p.
Download (direct link): photoshopcsbible2004.pdf
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Color Space: Select an option from this pop-up menu to specify the color model you want to use. Select RGB to open the image in the RGB mode; select LAB to open the image in the Lab mode. You can also select from 8 Bits/Channel to edit the image in 24-bit color or 16 Bits/Channel to open the image in 48-bit color.
Orientation: The preview in the left side of the dialog box shows you the original orientation of the image. If you want to change that orientation, click the other Orientation radio button. The preview updates to show you the new orientation.
Photoshop cannot save to the Photo CD format. And frankly, there's little reason you'd want to do so. Photo CD is strictly a means for transferring slides and film negatives onto the world's most ubiquitous and indestructible storage medium, the CD-ROM.Note
Kodak also offers a product called Picture CD, which is quite different from Photo CD don't get the two confused. With Picture CD, consumers can drop off rolls of undeveloped film and receive both traditional prints and a CD containing scanned versions of their pictures. Picture CD images are provided in the JPEG format, so none of the Photo CD file-opening features discussed here apply. You
© 2004 ... Your company
Part I: Welcome to Photoshop
94
open Picture CD images like any other JPEG file.Opening raw documents
A raw document is a plain binary file stripped of all extraneous information. It contains no compression scheme, specifies no bit depth or image size, and offers no color mode. Each byte of data indicates a brightness value on a single color channel, and that's it. Photoshop offers this function specifically so you can open images created in undocumented formats, such as those created on mainframe computers.
To open an image of unknown origin on a PC, choose File ® Open As. On a Mac, choose File ® Open and select All Documents from the Show pop-up menu. Then select the desired image from the scrolling list and choose Photoshop Raw (*. RAW) from the Open As pop-up menu (or Format pop-up menu on the Mac). After you press Enter or Return, the Raw Options dialog box appears, featuring these options:
Width, Height: If you know the dimensions of the image in pixels, enter the values in these option boxes.
Swap: Click this button to swap the Width value with the Height value.
Count: Enter the number of color channels in this option box. If the document is an RGB image, enter 3; if it is a CMYK image, enter 4.
Interleaved: Select this value if the color values are stored sequentially by pixels. In an RGB image, the first byte represents the red value for the first pixel, the second byte represents the green value for that pixel, the third the blue value, and so on. If you turn this check box off, the first byte represents the red value for the first pixel, the second value represents the red value for the second pixel, and so on. When Photoshop finishes describing the red channel, it describes the green channel and then the blue channel.
Depth: Select the number of bits per color channel. Most images contain 8 bits per channel, but scientific scans from mainframe computers may contain 16.
Byte Order: If you specify 16 bits per channel, you must tell Photoshop whether the image comes from a Mac or a PC.
Header: This value tells Photoshop how many bytes of data at the beginning of the file consist of header information it can ignore.
Retain When Saving: If the Header value is greater than zero, you can instruct Photoshop to retain this data when you save the image in a different format.
Guess: If you know the Width and Height values, but you don't know the number of bytes in the header or vice versa you can ask Photoshop for help. Fill in either the Dimensions or Header information and then click the Guess button to ask Photoshop to take a stab at the unknown value. Photoshop estimates all this information when the Raw Options dialog box first appears. Generally speaking, if it doesn't estimate correctly the first time around, you're on your own. But hey, the Guess button is worth a shot.Tip
If a raw document is a CMYK image, it opens as an RGB image with an extra masking channel. To display the image correctly, choose Image ® Mode ® Multichannel to free the four channels from their incorrect relationship. Then recombine them by choosing Image ® Mode ® CMYK Color.Note Don't confuse Photoshop Raw with Camera Raw, which is the untreated image created by a digital camera before processing. Camera Raw is as impressive as Photoshop Raw is bland. We'll be taking a closer look at Camera Raw in Chapter 17.Saving a raw document
Photoshop also lets you save to the raw document format. This capability is useful when you create files you want to transfer to mainframe systems or output to devices that don't support other formats, such as the Kodak XL7700.Caution
Do not save 256-color indexed images to the raw format or you will lose the color lookup table and, therefore, all color information. Be sure to convert such images first to RGB or one of the other full-color modes before saving.
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