2026-08-24
A frame requires two passes to scan, the first pass scans only odd-numbered lines, and the second pass only scans even-numbered lines. This scanning method is interlaced scanning. There are three problems that traditional interlaced scanning cannot solve. The field frequency is close to the frequency at which the human eye is sensitive to flicker, and obvious flickering will be felt when viewing a large-area light-colored background picture; the odd-even cycle of interlaced scanning results in obvious inter-scan line flicker, which is most obvious when viewing text information; the odd-even cycle of interlaced scanning causes the picture to show obvious and neatly arranged row structure lines, and the larger the screen size, the more obvious the row structure lines will be, affecting the reflection of picture details and the overall picture effect.
In the progressive scanning mode, each frame is composed of several horizontal scanning lines. If all the lines in this frame are completed one row after another from top to next, we call this scanning mode progressive scanning. Progressive scanning has non-linear signal processing technology to achieve accurate motion detection and motion compensation, thereby overcoming the three major shortcomings of traditional scanning methods. We can make a comparison. In interlaced scanning, odd-numbered lines are scanned first, and then even-numbered lines are scanned in the next 50th of a second. However, progressive scanning completes scanning of the entire image in 1/50th of a second. The picture scanned out line by line is clear and flicker-free, and the dynamic distortion is small. If used in conjunction with progressive scan TV and digital high-definition TV, you can achieve picture quality comparable to movies per second.
