PDF (adobe.com)

Save a file in JPEG format

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. You can also save an image as one or more JPEG using the Save For Web & Devices command.

Note: JPEG is only available when the image is 8 Bits/Channel (it only supports 8 Bit/Channel).
To quickly save a medium-quality JPEG, play the Save As JPEG Medium action on the file. You can access this action by choosing Production from the Actions panel menu.
  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
    Offers matte color choices to simulate the appearance of background transparency in images that contain transparency.

    Image Options
    Specifies 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
    Specifies the format of your JPEG file. Baseline (“Standard”) uses a format recognized by most web browsers. Baseline Optimized creates a file with optimized color and a slightly smaller file size. Progressive displays a series of increasingly detailed versions of the image (you specify how many) as it downloads.
    Note: Not all web browsers support optimized and Progressive JPEG images.
    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 can’t read your JPEG file (in any color mode), try saving the file without a thumbnail preview.