Saving files in JPEG format (Photoshop)

You can use the Save As command to save CMYK, RGB, and grayscale images in JPEG format. JPEG compresses file size by selectively discarding data. For more information, see About file compression and JPEG.
Note: You can also save an image as one or more JPEG files using the Save for Web command (Photoshop) or the Save Optimized command (ImageReady). For more information on optimizing images, see Optimizing images.

To save a file in JPEG format:

1. Choose File > Save As and choose JPEG from the Format menu.
2. In the JPEG Options dialog box, select the options you want, and click OK.
Matte
If the image contains transparency, choose a Matte color to simulate the appearance of background transparency. For more information on simulating transparency using the Matte option, see Optimization options for GIF and PNG-8 formats.
Image Options
To specify the image quality, choose an option from the Quality menu, drag the Quality pop-up slider, or enter a value between 0 and 12 in the Quality text box.
Format Options
Select Baseline ("Standard") to use a format recognized by most Web browsers, Baseline Optimized for optimized color and a slightly smaller file size, or Progressive to display a series of increasingly detailed scans (you specify how many) as the image downloads. Baseline Optimized and Progressive JPEG images are not supported by all Web browsers.
Size
To view the estimated download time, select a modem speed. (The Size preview is only available when Preview is selected.)
Note: Some applications may not be able to read a CMYK file saved in JPEG format. In addition, if you find that a Java application cannot read your JPEG file (in any color mode), try saving the file without a thumbnail preview.