You can open files using the Open command and Open Recent command. You can also open files into Photoshop from Adobe Bridge or Adobe® Photoshop® Lightroom™.
When opening certain files, such as camera raw and PDF, you specify settings and options in a dialog box before the files completely open in Photoshop.
In addition to still images, Photoshop® CS3 Extended users can open and edit video and image sequence files. For more information, see Import video files and image sequences (Photoshop Extended).
Sometimes Photoshop may not be able to determine the correct format for a file. This can happen, for example, because the file has been transferred between two operating systems. Sometimes a transfer between Mac OS and Windows can cause the file format to be mislabeled. In such cases, you must specify the correct format in which to open the file.
If a file was saved with an extension that doesn’t match its true format (for example, a PSD file saved with a .gif extension), or has no extension, Photoshop may not be able to open the file. Selecting the correct format will allow Photoshop to recognize and open the file.
(Windows) Choose File > Open As, and select the file you want to open. Then choose the desired format from the Open As pop‑up menu, and click Open.
(Mac OS) Choose File > Open, and choose All Documents from the Show pop‑up menu. Then select the file you want to open, choose the desired file format from the Format pop‑up menu, and click Open.