Opening special files in Photoshop

Photoshop needs to know the image format of a file (that is, whether it’s a TIFF, PCX, PSD, or JPEG file, for example) before it can open the file. Photoshop uses different methods in Windows and Mac OS to determine the format of an image file:

-->In Windows, Photoshop looks at the file extension (.tif, .pcx, .psd, and so forth), and if it finds a standard image format extension, it assumes that the file was saved using that format.

-->The Mac OS X uses a similar system based on filename extensions. The difference is that the file extensions may or may not be hidden. Showing or hiding file extensions can be accomplished via any file’s “Info” dialog. Select the file in the Mac OS X Finder, press Ô+I, and the Info dialog pops up. Here you can show or hide the extension for that file, and change what application is associated with that file (and all files with the same extension).

For compatibility reasons, Macintosh applications like Photoshop usually use the Windows file extension. However, when you move files from one platform to the other, they can easily be misidentified. With Photoshop’s Open As feature, you can specify the format you think (or know) that a given file uses. This facility works slightly differently in Windows than in the Mac OS.

Opening Photoshop special files using the Windows OS
In Windows, follow these steps:
1. Choose File➪Open As. The Open As dialog box appears.
2. Navigate to the file you want to open.
3. From the Open As drop-down list, choose the file format you want to use.
4. Double-click the file’s icon.
If you’ve chosen the right format, the file opens in Photoshop.
If the file doesn’t open, you may have chosen the wrong format. Choose another and try again.

Opening special files using the Mac OS
The standard Open dialog box includes a Format list at the bottom. Make sure that the Show list displays All Readable Documents. Then you can choose the file format you’d like to try directly from the Format list.