Fundamental Concepts in Component Video

• High-end video systems, such as for studio – Three separated video signals -- Red，Green and Blue image plane – Three wires connecting to Camera or other devices to TV or monitor Television Standards

• NTSC Video – USA, Canada, Japan and Koreaɼ 1953 by USA • PAL Video – Germany, England and China, 1962 by Germany • SECAM Video – France, Russiaɼ 1966 by France Standards Distribution NTSC Video

• NTSC (National Television System Committee) TV standard is mostly used in North America and Japan. It uses the familiar 4:3 (i.e., the ratio of picture width to its height) and uses 525 scan lines per frame at 30 frames per second (fps). • The problem is that NTSC is an analog system. In computer video, colors and brightness are represented by numbers (digital). But with analog television, everything is just voltages, and voltages are affected by wire length, connectors, heat, cold, video tape, and so on. a) NTSC follows the interlaced scanning system, and each frame is divided into two fields, with 262.5 lines/field. b) Thus the horizontal sweep frequency is 525×29.97 ≈ 15, 734 lines/sec, PAL Video

• PAL (Phase Alternating Line) is a TV standard widely used in Western Europe, China, India, and many other parts of the world. • PAL uses 625 scan lines per frame, at 25 frames/second, with a 4:3 aspect ratio and interlaced fields. SECAM Video

• SECAM stands for Système Electronique Couleur Avec Mémoire, the third major broadcast TV standard. • SECAM also uses 625 scan lines per frame, at 25 frames per second, with a 4:3 aspect ratio and interlaced fields. • SECAM and PAL are very similar. They differ slightly in their color coding scheme: (a) In SECAM, U and V signals are modulated using separate color subcarriers at 4.25 MHz and 4.41 MHz respectively. (b) They are sent in alternate lines, i.e., only one of the U or V signals will be sent on each scan line. Digital video

• Chroma Subsampling • High Definition TV • Video image quality Chroma Subsampling

• Chroma subsampling is the practice of encoding images by implementing less resolution for chroma information than for luma information. It is used in many video encoding schemes — both analog and digital Chroma Subsampling

High definition TV (HDTV)

• refers to video having resolution substantially higher than traditional television systems. HD has one or two million pixels per frame. • The first generation of HDTV was based on an analog technology developed by Sony in Japan in the late 1970s. High definition TV (HDTV)

• The main thrust of HDTV (High Definition TV) is not to increase the “definition” in each unit area, but rather to increase the visual field especially in its width. (a) The first generation of HDTV was based on an analog technology developed by Sony and NHK in Japan in the late 1970s. (b) MUSE (MUltiple sub-Nyquist Sampling Encoding) was an improved NHK HDTV with hybrid analog/digital technologies that was put in use in the 1990s. It has 1,125 scan lines, interlaced (60 fields per second), and 16:9 aspect ratio. (c) Since uncompressed HDTV will easily demand more than 20 MHz bandwidth, which will not fit in the current 6 MHz or 8 MHz channels, various compression techniques are being investigated. (d) It is also anticipated that high quality HDTV signals will be transmitted using more than one channel even after compression. High definition TV (HDTV)

• HDTV: Example

High definition TV (HDTV)

• The FCC has planned to replace all analog broadcast services with digital TV broadcasting by the year 2009. The services provided will include: – SDTV (Standard Definition TV): the current NTSC TV or higher. – EDTV (Enhanced Definition TV): 480 active lines or higher, i.e., the third and fourth rows in Table 5.4. – HDTV (High Definition TV): 720 active lines or higher. Video Aspect Ratios

• 4:3 = 1.33:1 16:9 aspect ratio is a • 16:9= 1.78:1 “average” • 2.35:1 ( between 2.35:1 format) and 1.33:1(4:3). • 1.85:1 (Film format) • 2.21:1 (Film format) Standard video aspect ratio 4:3

720 pixels • Resolution in standard video is 720x576. • This Format is designed to carry video with 4:3 aspect ratio.

576 pixels 16:9 aspect ratio - anamorphic widescreen

• 16:9 aspect ratio transmitted in a traditionally 4:3 system is called anamorphic widescreen format. • Ideally the horizontal resolution for standard definition widescreen should have been 960x576 pixels to have the same pixel density as 4:3 720x576 displayed on a 4:3 TV with the same screen height as a the 16:9 SDTV. 16:9 anamorphic converted to a 4:3 letterbox Original film formats letterboxed to fit in 4:3 frame The End

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