CHAPTER 7 FILES AND FILE FORMATS 91■ Area-specific encoding. You can select which regions should receive a
higher-quality compression. The process is taken care of during compression;
no requirements are placed on the decoder.
■ Error resilience.JPEG2000 uses a packet-type codestream, resync markers,
table of content markers, and start-of-packet and end-of-packet markers that
add more error resilience.The JPEG2000 format hasn’t really taken off yet, and many wonder whether it will.
As of this writing, Internet Explorer, Mozilla, Opera, and Apple’s Safari browser do
not include the capability to open JPEG2000 images (QuickTime does, however).
ActiveX plug-ins are available for both Internet Explorer and Mozilla that enable
you to view these files.
When the browser manufacturers finally put this standard in their browsers, the out-
look for JPEG2000 may improve. However, this was predicted for the Portable
Network Graphics (PNG) format, and it still hasn’t caught the attention of most pro-
fessional Web developers.TIFF File Format
TIFF (Tagged Image File Format) comes closest to a universal file format for photog-
raphers--most imaging software can read it. TIFF stores images in a variety of bit
depths in both RGB and CMYK. It includes lossless
compression, and is designed into most imaging hard-
ware, such as digital cameras and scanners.
The TIFF format supports the Grayscale, Indexed
Color, RGB, YcbCr, CMYK, and CIELab (LAB) color
spaces.
One minor drawback to TIFF is that it cannot store
vector graphics, such as Photoshop text or paths.
Also, there is no progressive load option, as with
GIF and JPEG images.
When you click File, Save As and choose the TIFF
format, the somewhat intimidating TIFF Options
dialog box appears. Read through these options to
overcome any fears:
■ Image Compression: None. Save the file
with no compression. TIFF files have a four-
gigabyte file size limit. Ideally none of your
images will be that large!Photoshop TIFF files
can store annotations.
Photoshop Elements can open
and display these annotations,
but they cannot be edited (see
Figure 7.6). Other software pro-
grams, including older versions of
Photoshop, do not display these
annotations, however.