SECAM
SECAM, which stands for Séquentiel couleur à mémoire (Sequential Color with Memory) is an analog television video format standard and color encoding system developed in France in the 1960s as an alternative to other video format standards and color encoding systems such as NTSC and PAL. SECAM refers to both the video format and the color encoding system employed in analog NTSC broadcasts. It is primarily used in countries such as France, Russia, parts of Eastern Europe, and some African nations.
SECAM operates by sequentially transmitting color information in analog video signals. Unlike NTSC and PAL, which use composite video signals, SECAM separates the color information into two distinct signals known as the R-Y (red minus luminance) and B-Y (blue minus luminance) components. This separation allows for compatibility with black-and-white CRT displays while maintaining backward compatibility with monochrome television sets.
In SECAM, the color information is transmitted in a sequential manner, with each line divided into two half-lines. One half-line carries the color information for the even-numbered pixels, and the other half-line carries the color information for the odd-numbered pixels. This sequential transmission method helps minimize color bleeding and interference between adjacent pixels. SECAM has a frame rate of 25 frames per second (50 fields per second) and a resolution of 625 lines.
One of the advantages of SECAM is its resistance to certain types of interference, particularly cross-color artifacts that can occur when NTSC and PAL signals are improperly converted or displayed.