SECAM system

SECAM, which stands for système électronique couleur avec mémoire, is a color television broadcasting system developed in France and adopted by several other countries, including those in Eastern Europe and the Soviet Union. It was introduced in 1967 as a modification of the American NTSC system.12

SECAM differs from NTSC and PAL by transmitting color information sequentially rather than simultaneously. Each line scan carries luminance information along with either red or blue color values. The green component is then derived in the receiver by subtracting the red and blue signals from the luminance signal. To achieve this, SECAM receivers use a delay line to store the information from one line scan while the next line is being processed, hence the "with memory" in its name. This method reduces color detail in the vertical dimension but is less susceptible to phase errors that can affect hue accuracy in other systems.12