1080i

1080i is a high-definition video format that uses interlaced scanning with a native resolution of 1920x1080. The “i” stands for interlaced, meaning each displayed frame is made up of two fields: one field contains all odd-numbered lines and the other contains all even-numbered lines. When the two fields are combined, the image yields 1080 visible lines of vertical resolution in a 16:9 image.

In broadcast terms, 1080i is commonly delivered at about 59.94 fields per second for 1080i60 (typical of NTSC regions), which corresponds to roughly 29.97 frames per second, and 50 fields per second for 1080i50 (typical of PAL regions), which corresponds to 25 frames per second. The format has been widely used in HDTV broadcasting and is supported by major delivery standards such as ATSC and DVB. Blu-ray discs and some streaming services also carry 1080i content, though many platforms favor 1080p or adaptive streaming.

On display devices, 1080i content is usually deinterlaced to produce a progressive image. The perceived motion quality depends on the deinterlacing algorithm and the source material; poor deinterlacing can cause visual artifacts during fast motion. In terms of bandwidth, 1080i generally requires less data than a true 1080p signal at the same temporal resolution, though modern encoders can deliver comparable quality with progressive formats.

Compared with 1080p, 1080i trades potential motion clarity for compatibility with traditional broadcast infrastructure and lower bandwidth. It remains common for live television broadcasts and some regional services, while progressive 1080p has become more prevalent in Blu-ray and online streaming.