Saving files in JPEG 2000 format (Photoshop optional plug-in)

To save files in the JPEG 2000 format, the optional JPEG 2000 plug-in must be installed in Adobe Photoshop CS/Plug-Ins/Adobe Photoshop Only/File Formats. The optional JPEG 2000 plug-in can be found on the Photoshop CS installation CD in Goodies/Optional Plug-Ins/Photoshop Only/File Formats. You can save images in extended JPEG 2000 (JPF) format, which provides an expanded set of options compared to the standard JPEG 2000 (JP2) format. However, you can make files JP2 compatible by selecting the appropriate option in the JPEG 2000 dialog box. For more information on the JPEG 2000 format, see JPEG 2000 (Photoshop optional plug-in).

Note: You cannot save Duotone, Multichannel, or Bitmap mode images in JPEG 2000 format. To save these files as JPEG 2000, first convert them to RGB color.

To save a file in JPEG 2000 format:

1. Choose File > Save As, and choose JPEG 2000 from the Format menu.
2. Specify a filename and location, select saving options, and click Save, which opens the JPEG 2000 dialog box.

Important: If you want to save a JP2-compatible file, you must select the ICC Profile option (Windows) or the Embed Color Profile option (Mac OS) in the Save As dialog box. Otherwise, the JP2 Compatible option will be unavailable in the JPEG 2000 dialog box. The JP2-compatible option slightly increases the JPF file size. Keep in mind that JP2 viewers are not required to support ICC profiles and metadata present in JPF files, so color fidelity and other features may not work as expected.

3. (Optional) Enter a value in the File Size text box to set a target size for the saved file. The value in the Quality text box will adjust to the best quality for the file size you enter.
4. Do one of the following to specify the image quality:
• Select Lossless to compress the image without losing image quality. Selecting this option creates a larger file.
• Deselect Lossless to create a smaller file. Then drag the Quality pop-up slider or enter a value in the Quality text box to specify the image quality. A higher quality value results in better image quality and a larger file size.

If you specify an image quality that conflicts with a target file size you entered previously, Photoshop automatically changes the value in the File Size text box.

5. Select Fast Mode for faster previewing or encoding of the image. File size control, progressive optimization, and lossy with integer wavelet filter are not supported in Fast Mode.
6. Select Include Metadata to include file information. If your image file contains paths and you wish to store the paths information in the JPEG 2000 file, the Metadata option must be selected.

Deselect the Include Metadata and Include Color Settings options to make the image file size smaller.

7. Select Include Transparency to preserve transparency that exists in the original image. The Include Transparency option is dimmed if the image does not contain transparency.
8. Select JP2 Compatible to create a file that can be displayed in viewing software that supports standard JPEG 2000 (JP2) format but does not support extended JPEG 2000 (JPF) format.
9. Click the Advanced Options button to set the following options:

Compliance

Chooses the types of devices with which the file is compliant. Currently, only general devices (such as Web browsers) are supported.

Wavelet Filter

Specifies the type of numbers (coefficients) used to encode the file. Float is more accurate but cannot be used for Lossless compression. Selecting the Lossless compression option automatically sets the Wavelet Filter option to Integer.

Choose Float or Integer depending on your image and the result you want. Integer is usually the best option for an overall consistent appearance in the image. Float may sharpen the image but could cause it to lose some quality around edges.

Tile Size

Chooses the size of the tiles used in the image. When low quality values are used to optimize images smaller than 1024 x 1024 pixels, using the largest tile size will produce better results.

A tile size of 1024 is best for most images. When creating files with small dimensions (for cell phones, and so forth), a lower tile size should be used.

Metadata Format

Select the metadata format(s) to include in the image file. JPEG2000 XML is JPEG 2000-specific XML data; this option is only available if the image file contains this data. XMP is File Info data and EXIF is digital camera data.

Color Settings Format

Select the Color Settings Format to include in the image file. The ICC Profile option includes the full ICC profile specified in the Save As dialog box and is the default option. The Restricted ICC Profile option is intended for use in portable devices such as cell phones and PDAs. A Restricted ICC Profile must be in a JP2 file.

10. Choose an Optimization Order from the Order menu:

Growing Thumbnail

Presents a sequence of small thumbnail images increasing in size until they reach the image's full size.

Progressive

Presents an image that displays increasingly detailed versions of the entire image as data becomes available (for example, streaming over the Web to a browser). Progressive JPEG images have a slightly larger file size, require more RAM for viewing, and are not supported by all applications and JPEG 2000 viewing software.

Color

Makes the image appear first as a grayscale image, then as a color image.

Region of Interest

If your Photoshop document contains one or more alpha channels, you can choose an alpha channel to define a Region of Interest.

Once the alpha channel is loaded as a Region of Interest, choose an Enhance value to increase or decrease the quality of the Region of Interest relative to the rest of the image. Note that Enhance does not change the file size of the image, so enhancing the area inside the alpha channel will decrease the quality of the area outside the alpha channel (and vice versa).

The Region of Interest and Enhance options are not available if your Photoshop document does not have an alpha channel.

Note: The channel (alpha, spot, or Quick Mask) used to define the Region of Interest will be discarded in the final saved JPEG 2000 file.

11. To preview how the image will appear in JPEG 2000 viewing software, make sure you chose an Optimization Order in step 10. The Preview option takes into consideration how the image is optimized and will open the image accordingly. In the Download Preview area of the JPEG 200 dialog box, choose a download rate from the pop-up menu to view the estimated download time of the image, then click the Preview button.

You can use the Set Preview Zoom pop-up menu to zoom in or out of the image for better viewing. You can also use the Zoom tool and the Hand tool to adjust the viewing area of your preview.

12. When you're done setting options, click OK to generate the JPEG 2000 image file.