SECAM in the context of Analog television

Color television (American English) or colour television (British English) is a television transmission technology that also includes color information for the picture, so the video image can be displayed in color on the television set. It improves on the monochrome or black-and-white television technology, which displays the image in shades of gray (grayscale). Television broadcasting stations and networks in most parts of the world transitioned from black-and-white to color broadcasting between the 1960s and the 1980s. The invention of color television standards was an important part of the history and technology of television.

Transmission of color images using mechanical scanners had been conceived as early as the 1880s. A demonstration of mechanically scanned color television was given by John Logie Baird in 1928, but its limitations were apparent even then. Development of electronic scanning and display made a practical system possible. Monochrome transmission standards were developed prior to World War II, but civilian electronics development was frozen during much of the war. In August 1944, Baird gave the world's first demonstration of a practical fully electronic color television display. In the United States, competing color standards were developed, finally resulting in the NTSC color standard that was compatible with the prior monochrome system. Although the NTSC color standard was proclaimed in 1953, and limited programming soon became available, it was not until the early 1970s that color television in North America outsold black-and-white units. Color broadcasting in Europe did not standardize on the PAL or SECAM formats until the 1960s.

NTSC (from National Television System Committee) was the first American standard for analog television, published and adopted in 1941. In 1957, the EIA defined NTSC performance standards in EIS-170 (also known as RS-170). In 1961, the color version of NTSC was designated NTSC-M by the CCIR, with the Japanese variant, which used a somewhat different color implementation, designated NTSC-J.

In 1953, a second NTSC standard was adopted, which allowed for color television broadcast compatible with the then existing stock of black-and-white receivers. It was one of three major color formats for analog television, the others being PAL and SECAM. NTSC color was usually associated with the System M; this combination was sometimes called NTSC II. The only other broadcast television system to use NTSC color was the System J. Brazil used System M with PAL color. Vietnam, Cambodia, and Laos used System M with SECAM color. Vietnam later switched to PAL in the early 1990s.

Phase Alternating Line (PAL) is a colour encoding system for analogue television. It was one of three major analogue colour television standards, the others being NTSC and SECAM. In most countries it was broadcast at 625 lines, 50 fields (25 frames) per second, and associated with CCIR analogue broadcast television systems B, D, G, H, I and K. The articles on analogue broadcast television systems further describe frame rates, image resolution, and audio modulation.

PAL video is composite video because luminance (luma, monochrome image) and chrominance (chroma, colour applied to the monochrome image) are transmitted together as one signal. A latter evolution of the standard, PALplus, added support for widescreen broadcasts with no loss of vertical image resolution, while retaining compatibility with existing sets. Almost all of the countries using PAL are currently in the process of conversion, or have already converted transmission standards to DVB, ISDB or DTMB. The PAL designation continues to be used in some non-broadcast contexts, especially regarding console video games where it is referring to the markets other than North America and Japan.

${\displaystyle B-Y}$ indicates a color difference signal between blue (B) and a luminance component, as part of a luminance (Y) and chrominance (C) color model. It has different meanings depending on the exact model used:

• U in YUV, a generic model used for analog and digital image formats
• Cb in YCbCr, used for digital images and video
• Pb in YPbPr, used in analog component video
• Db in YDbDr, used in analog SECAM

${\displaystyle R-Y}$ indicates a color difference signal between red (R) and a luminance component, as part of a luminance (Y) and chrominance (C) color model. It has different meanings depending on the exact model used:

• V in YUV, a generic model used for analog and digital image formats
• Cr in YCbCr, used for digital images and video
• Pr in YPbPr, used in analog component video
• Dr in YDbDr, used in analog SECAM

Broadcast television systems (or terrestrial television systems outside the US and Canada) are the encoding or formatting systems for the transmission and reception of terrestrial television signals.

Analog television systems were standardized by the International Telecommunication Union (ITU) in 1961, with each system designated by a letter (A-N) in combination with the color standard used (NTSC, PAL or SECAM) - for example PAL-B, NTSC-M, etc.). These analog systems for TV broadcasting dominated until the 2000s.

Amateur television (ATV) is the transmission of broadcast quality video and audio over the wide range of frequencies of radio waves allocated for radio amateur (ham) use. ATV is used for non-commercial experimentation, pleasure, and public service events. Ham TV stations were on the air in many cities before commercial television stations came on the air. Various transmission standards are used, these include the broadcast transmission standards of NTSC in North America and Japan, and PAL or SECAM elsewhere, utilizing the full refresh rates of those standards. ATV includes the study of building of such transmitters and receivers, and the study of radio propagation of signals travelling between transmitting and receiving stations.

ATV is an extension of amateur radio. It is also called ham TV or fast-scan TV (FSTV), as opposed to slow-scan television (SSTV).

CCIR System M, sometimes called 525–line, NTSC, NTSC-M, or CCIR-M, is the analog broadcast television system approved by the FCC (upon recommendation by the National Television System Committee - NTSC) for use in the United States since July 1, 1941, replacing the 441-line TV system introduced in 1938. It is also known as EIA standard 170. System M comprises a total of 525 interlaced lines of video, of which 486 contain the image information, at 30 frames per second. Video is amplitude modulated and audio is frequency modulated, with a total bandwidth of 6 MHz for each channel, including a guard band.

It was also adopted in the Americas and Caribbean; Myanmar, Philippines, South Korea, Taiwan, Thailand, and Japan (here with minor differences, informally referred to as System J). System M doesn't specify a color system, but NTSC color encoding was normally used, with some exceptions: NTSC-J in Japan, PAL-M in Brazil and SECAM-M in Cambodia, Laos, and Vietnam (see Color standards section below).

NTSC-J or "System J" is the informal designation for the analogue television standard used in Japan. The system is based on the US NTSC (NTSC-M) standard with minor differences. While NTSC-M is an official CCIR and FCC standard, NTSC-J or "System J" are a colloquial indicators.

The system was introduced by NHK and NTV, with regular color broadcasts starting on 10 September 1960.

625-line (or CCIR 625/50) is a late 1940s European analog standard-definition television resolution standard. It consists of a 625-line raster, with 576 lines carrying the visible image at 25 interlaced frames per second. It was eventually adopted by countries using 50 Hz utility frequency as regular TV broadcasts resumed after World War II. With the introduction of color television in the 1960s, it became associated with the PAL and SECAM analog color systems.

A similar 525-line system was adopted by countries using 60 Hz utility frequency (like the US). Other systems, like 375-line, 405-line, 441-line, 455-line, and 819-line existed, but became outdated or had limited adoption.

CCIR System B (originally known as the "Gerber Standard") was the 625-line VHF analog broadcast television system which at its peak was adopted by more than one hundred countries, either with PAL or SECAM colour. It is usually associated with CCIR System G for UHF broadcasts.

System B was the first internationally accepted 625-line broadcasting standard in the world. A first 625-line system with a 8 MHz channel bandwidth was proposed at the CCIR Conference in Stockholm in July 1948 (based on 1946-48 studies in the Soviet Union by Mark Krivosheev). At a CCIR Geneva meeting in July 1950 Dr. Gerber (a Swiss engineer), proposed a modified 625-lines system with a 7 MHz channel bandwidth (based on work by Telefunken and Walter Bruch), with the support of Belgium, Denmark, Italy, Netherlands, Sweden, and Switzerland. Known as the "Gerber-norm", it was eventually approved along with four other broadcast standards on the next formal CCIR meeting in May 1951 in Geneva.

CCIR System D is an analog broadcast television system used in Bulgaria, Latvia, Lithuania, Poland, Romania, Slovakia, Czech Republic, Hungary, Albania, and the People's Republic of China, Mongolia, Kyrgyzstan, North Korea, Tajikistan, Turkmenistan, Uzbekistan, Armenia, Azerbaijan, Georgia, Kazakhstan, Moldova, Russia, Ukraine, and Belarus paired with the PAL/SECAM colour.

Initially known as the I.B.T.O. 625-line system this was the first 625-line system, developed by Mark Krivosheev in 1948, and later associated with the SECAM and PAL color systems. Used on VHF only in most countries, it usually combined with System K on UHF. In China, it is used for both VHF and UHF.

CCIR System K is an analog broadcast television system used in countries that adopted CCIR System D on VHF, and in Benin, Guinea, Republic of the Congo, Togo, Senegal, Burkina Faso, Burundi, Ivory Coast, Gabon, Comoros, Democratic Republic of the Congo, Madagascar, Mali, Nigeria, Réunion, Rwanda, Chad, Central African Republic, French Polynesia, New Caledonia, Wallis and Futuna, Guadeloupe, Martinique, Saint Pierre and Miquelon, and French Guiana.

It is identical System D in most respects. Used only for UHF frequencies, its paired with SECAM or PAL color systems.

YDbDr, sometimes written ${\displaystyle YD_{B}D_{R}}$, is the colour space used in the SECAM (adopted in France and some countries of the former Eastern Bloc) analog colour television broadcasting standard. It is very close to YUV (used on the PAL system) and its related colour spaces such as YIQ (used on the NTSC system), YPbPr and YCbCr.

${\displaystyle YD_{B}D_{R}}$ is composed of three components: ${\displaystyle Y}$, ${\displaystyle D_{B}}$ and ${\displaystyle D_{R}}$. ${\displaystyle Y}$ is the luminance, ${\displaystyle D_{B}}$ and ${\displaystyle D_{R}}$ are the chrominance components, representing the red and blue colour differences.

Enhanced-definition television, or extended-definition television (EDTV) is a Consumer Electronics Association (CEA) marketing shorthand term for certain digital television (DTV) formats and devices. Specifically, this term defines an extension of the standard-definition television (SDTV) format that enables a clearer picture during high-motion scenes compared to previous iterations of SDTV, but not producing images as detailed as high-definition television (HDTV).

The term refers to devices capable of displaying 480-line or 576-line signals in progressive scan, commonly referred to as 480p (NTSC-HQ) and 576p (PAL-HQ/SECAM) respectively, as opposed to interlaced scanning, commonly referred to as 480i (NTSC) or 576i (PAL, SECAM). High-motion is optional for EDTV.