Adobe photoshop cs2 사용자 설명서

ADOBE PHOTOSHOP CS2 

Joint Photographic Experts Group (JPEG) format is commonly used to display photographs and other continuous­
tone images in hypertext markup language (HTML) documents over the World Wide Web and other online services. 
JPEG format supports CMYK, RGB, and Grayscale color modes, and does not support alpha channels. Unlike GIF 
format, JPEG retains all color information in an RGB image but compresses file size by selectively discarding data. 

A JPEG image is automatically decompressed when opened. A higher level of compression results in lower image 
quality, and a lower level of compression results in better image quality. In most cases, the Maximum quality option 
produces a result indistinguishable from the original. 

JPEG 2000 is a file format that provides more options and greater flexibility than the standard JPEG (JPG) format. 
Using JPEG 2000, you can produce images with better compression and quality for both web and print publishing. 
To save files in the JPEG 2000 format, you must locate the optional JPEG 2000 plug-in and install it in this location: 
Adobe Photoshop CS/Plug-Ins/Adobe Photoshop Only/File Formats. You can find the plug-in on the Photoshop CS 
installation CD in Goodies/Optional Plug-Ins/Photoshop Only/File Formats. 

Unlike traditional JPEG files, which are lossy, the JPEG 2000 format supports optional lossless compression. The 
JPEG 2000 format also supports 16-bit color or grayscale files and 8-bit transparency, and it can retain alpha channels 
and spot channels. Grayscale, RGB, CMYK, and Lab are the only modes supported by the JPEG 2000 format. 

The JPEG 2000 format also supports using a region of interest (ROI) to minimize file size and preserve quality in 
critical regions of an image. By using an alpha channel, you can specify the area (ROI) where the most detail should 
be preserved, allowing greater compression and less detail in other regions. 

The Large Document Format (PSB) supports documents up to 300,000 pixels in any dimension. All Photoshop 
features, such as layers, effects, and filters, are supported. You can save high dynamic range, 32-bits-per-channel 
images as PSB files. Currently, if you save a document in PSB format, it can be opened only in Photoshop CS or 
Photoshop CS2. Other applications and earlier versions of Photoshop cannot open documents saved in PSB format. 

The Enable Large Document Format (.psb) option must be enabled in Preferences before you can save documents 
in PSB format. There is one exception: it is possible to open an existing PSB file and save it in PSB format even if the 
Enable Large Document Format (.psb) option is not selected in Preferences.