Page 219 - DCAP303_MULTIMEDIA_SYSTEMS

Unit 12: Image Format

self assessment notes
Choose the correct answer:

5. The JPEG standard is applicable to both grey scale and colour images.
( a) True (b) False
6. The ................... colour format is ideal for JPEG compression as it enables brightness and
colour information from an image to be separated.
( a) JPEG (b) YCbCr

( c) RGB (d) MCU
7. The .................. is supposed to become a standard as a multimedia framework.
( a) MPEG-1 (b) MPEG-2
( c) MPEG-4 (d) MPEG-21

8. ..................... is therefore highly suited for use in image databases and CD-ROM
applications.

( a) Compression (b) Raster image formats
( c) Pixels (d) Fractal compression

12.7 summary

• Image file formats are standardized means of organizing and storing digital images.

• Meta/Vector formats have it over Raster is that they are more than a simple grid of coloured
dots. They are actual vectors of data stored in mathematical formats rather than bits of
coloured dots.
• Compression is a computer term that represents a variety of mathematical formats used to
compress an image’s byte size.

• The structured formats are only used for illustrations (images which look like drawings),
rather than photo-realistic images.
• GIF images are compressed using the Lempel Ziv Welch (LZW) lossless data compression
technique to reduce the file size without degrading the visual quality.
• The JPEG algorithm generally does not use the RGB (Red, Green, and Blue) colour
format.
• The MPEG is not actually a format but short for Moving Picture Experts Group, a working
group of ISO/IEC that develops video and audio encoding standards.
12.8 Keywords

fractal: A fractal is a structure that is made up of similar forms and patterns that occur in many
different sizes.

Graphics interchange format (Gif): The GIF is a bitmap image format that was introduced by
CompuServe in 1987 and has since come into widespread usage on the World Wide Web due to
its wide support and portability.
Joint photographic experts Group (JpeG): The JPEG is an abbreviated form of Joint Photographic
Experts Group, the independent committee that created it as a standard for photography
compression.

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