Specifications
Print2CAD OCR 2013 - 104
17.1.2 JPEG
“In computing, JPEG (pronounced /ˈdʒeɪpɛɡ/, jay-peg) is a commonly used method of
lossy compression for photographic images. The degree of compression can be adjusted,
allowing a selectable tradeoff between storage size and image quality. JPEG typically
achieves 10:1 compression with little perceptible loss in image quality.
JPEG compression is used in a number of image le formats. JPEG is the most common
image format used by digital cameras and other photographic image capture devices; along
with JPEG/JFIF, it is the most common format for storing and transmitting photographic
images on the World Wide Web. These format variations are often not distinguished, and
are simply called JPEG.
The name JPEG stands for Joint Photographic Experts Group, the name of the committee
that created the JPEG standard and also other standards. It is one of two sub-groups of
ISO/IEC Joint Technical Committee 1, Subcommittee 29, Working Group 1 (ISO/IEC
JTC 1/SC 29/WG 1) - titled as Coding of still pictures. The group was organized in 1986,
issuing the rst JPEG standard in 1992, which was approved in September 1992 as ITU-T
Recommendation T.81 and in 1994 as ISO/IEC 10918-1.
The JPEG standard species the codec, which denes how an image is compressed into
a stream of bytes and decompressed back into an image, but not the le format used to
contain that stream. The Exif and JFIF standards dene the commonly used formats for
interchange of JPEG-compressed images.
On the other hand, JPEG is not as well suited for line drawings and other textual or iconic
graphics, where the sharp contrasts between adjacent pixels cause noticeable artifacts.
Such images are better saved in a lossless graphics format such as TIFF, GIF, PNG, or
a raw image format. (...)
Source: Wikipedia, subject “JPEG”
License Agreement: http://creativecommons.org/licenses/by-sa/3.0/
17.1.3 BMP
“The BMP le format, sometimes called bitmap or DIB le format (for device-indepen-
dent bitmap), is an image le format used to store bitmap digital images, especially on
Microsoft Windows and OS/2 operating systems.
Many older graphical user interfaces used bitmaps in their built-in graphics subsystems;
i.e. the Microsoft Windows and OS/2 platform‘s GDI subsystem, where the specic
format used is the Windows and OS/2 bitmap le format, usually named with the le