Optimization options for JPEG format
- Click the Matte color swatch and select a color in the color picker.
- Choose an option from the Matte menu.
- Select either Add Custom ImageReady Metadata (Backward Compatible), Add EXIF Metadata (JPEG Only), or Add XMP Metadata.
- If you choose XMP, then choose an XMP Option: Write Minimal Set of XMP, Include Reference to Source File, or Write XMP to Separate Files.
JPEG is the standard format for compressing continuous-tone images such as photographs. Optimizing an image as a JPEG format relies on lossy compression, which selectively discards data. (See About file formats.)
Note: In ImageReady, you can control which options show in the Optimize palette by clicking the Show Options control 
on the Optimize palette tab. To show all options, choose Show Options from the Optimize palette menu.
Quality
Choose an option from the Quality Level menu, or specify a value in the Quality text box. The higher the Quality setting, the more detail the compression algorithm preserves. However, using a high Quality setting results in a larger file size than using a low Quality setting. View the optimized image at several quality settings to determine the best balance of quality and file size.
You can use masks from type layers, shape layers, and alpha channels to vary the quality level across an image. This technique produces higher-quality results in critical image areas without sacrificing file size. (See Using weighted optimization.)
Optimized
Select Optimized to create an enhanced JPEG with a slightly smaller file size. The Optimized JPEG format is recommended for maximum file compression; however, some older browsers do not support this feature.
Progressive
Select Progressive to create an image that displays progressively in a Web browser. The image will display as a series of overlays, enabling viewers to see a low-resolution version of the image before it downloads completely.
Note: Progressive JPEGs require more RAM for viewing, and are not supported by some browsers.
Blur
Specify the amount of blur to apply to the image. This option applies an effect identical to that of the Gaussian Blur filter and allows the file to be compressed more, resulting in a smaller file size. A setting of 0.1 to 0.5 is recommended.
Preserve ICC Profile
Select Preserve ICC Profile to preserve the ICC profile of the artwork with the file. ICC profiles are used by some browsers for color correction. (See Using color management to produce consistent color.)
Matte
Specify a fill color for pixels that were transparent in the original image:
Pixels that were fully transparent in the original image are filled with the selected color; pixels that were partially transparent in the original image are blended with the selected color.
Add Metadata
(ImageReady) Select to include image metadata: