Early Color Television CTI/Sleeper Color System (1947) Another
scanning method was used by Color Television Inc. There was a
change of color not for each successive filed but for each line.
This system used 525 lines per picture frame and used 60
interlaced fields and 30 complete frames per second. The color
switching rate became the same as the line frequency, 15,750 per
second. In the CTI system, each horizontal line in any one field
was traced in a primary color which was different from colors in
the lines above and below. In each complete field one-third
trace the blue image, one-third trace the green image, and one-
third trace the red image. The CTI signal had the same
characteristics as a standard b&w signal except for the color
synchronizing. There were 525 lines per frame, 30 frames and 30
complete pictures per second. One frame consisted of two
interlaced fields, each with 262 1/2 lines, reproduced at a
frequency of 60 per second. The CTI video signals for the three
color images were transmitted one