Saving Images > Saving images in specific formats > JPEG format
><

JPEG format


Joint Photographic Experts Group (JPEG) format is commonly used to save photographs and other continuous-tone images. JPEG format retains all color information in an image but compresses file size by selectively discarding data. You can choose what level of compression you want when you save a JPEG file. A higher level of compression results in lower image quality and a smaller file size; a lower level of compression results in better image quality and a larger file size. In most cases, the Maximum quality option produces a result indistinguishable from the original.

JPEG is one of the standard formats for displaying images over the World Wide Web and other online services. You can save an image as a JPEG file. (See Optimizing images.)

To save a file in JPEG format:

1 Choose File > Save As, and choose JPEG from the format list.

2 Specify a filename and location, select saving options (as described in Saving images), and click Save, which opens the JPEG Options dialog box.

3 If the image contains transparency, select a Matte color to simulate the appearance of background transparency. (See Making transparent and matted images.)

4 Do one of the following to specify the image quality:
  • Choose an option from the Quality menu.
  • Drag the Quality pop-up slider.
  • Enter a value between 1 and 12 in the Quality text box.

    • 5 Select a format option:
  • Baseline ("Standard") to use a format that is recognizable to most Web browsers.
  • Baseline Optimized to optimize the color quality of the image and produce a slightly smaller file size. This option is not supported by all Web browsers.
  • Progressive to create an image that displays gradually as it is downloaded to a Web browser--in a series of scans (you specify how many) showing increasingly detailed versions of the entire image. Progressive JPEG images files are slightly larger in size, require more RAM for viewing, and are not supported by all applications and Web browsers.

    • 6 To view the estimated download time of the image, select a modem speed from the Size pop-up menu. (The Size preview is only available when Preview is selected.)

    Note: If you find that a Java application cannot read your JPEG file (in any color mode), try saving the file without a thumbnail preview.

    7 Click OK.

    Saving Images > Saving images in specific formats > JPEG format