PCX format
The formation of personal computer exchange
(PCX) image file has a developing process. The first prototype of PCX appeared
in ZSOFT's commercial software package for painting called PC PAINBRUSH. Later,
Microsoft transplanted it into Windows environment and became a sub-function of
Windows system. First, it is widely used in Microsoft Windows 3.1. With the
popularity and upgrade of Windows and its powerful image processing ability,
PCX, together with GIF, TIFF and BMP image file formats, is supported by more
and more graphics and image software tools, and more and more people pay
attention to it.
PCX was the first file format to support
color images, and now it can support up to 256 colors. PCX designers have
introduced color image file format ahead of time, making it a very popular image
file format.
PCX image file is composed of file header
and real image data. File header is composed of 128 bytes, which describes
version information, horizontal and vertical resolution of image display
device, and palette information. In real image data, it represents image data
type and color type. Data in PCX image files are compressed image data using
PCXREL technology.
PCX is the image file format of PC brush.
The image depth of PCX can be l, 4, 8 bit. Because this file format appeared
earlier, it does not support true color. PCX file uses RLE run-length encoding.
The compressed image data is stored in the file body. Therefore, when the
collected image data is written into PCX file format, RLE encoding should be
carried out. When reading a PCX file, RLE decoding should be done first to
display and process it further.
Advantage:
PCX is a standard format between many
Windows-based programs and MS-DOS-based programs.
PCX supports internal compression.
Disadvantages:
PCX is not supported by Web browsers
