Nowadays, we are moving into the HD world that provide us better resolution on the screen. When shopping for a HD television, you will often notice there are 2 major video formats supported, i.e. 1080i and 1080p. But do you know exactly what is the differences between HD 1080i and HD 1080p?

For HD 1080i (1920×1080), the 1080 refers to the number of interlaced pixel scan lines appearing on a screen – 1,080. The screen has 1,080 vertical pixels by 1,920 horizontal pixels. i stands for interlace scanning format which scanning “paints” the picture on the screen by first filling in all the odd-numbered scan lines then filling in all the even-numbered scan lines so that you only get half of the lines of the picture in the first scan and the second half of lines in the second scan. This all happens so quickly that human eye is tricked into seeing a complete picture.

On another hand, HD 1080p (1920×1080) means that the resolution of the picture is 1,920 vertical pixels by 1,080 horizontal pixels and p stands again for progressive scanning or non-interlaced. This scanning format works on the same principle as HD 720p that scans all the lines at once, thus giving a clearer and flicker-free picture. The only difference is that in this type there are more pixels and the resolution is better. As it’s considered as HDTV video mode, 1080p is sometimes referred to in marketing materials as “True High-Definition” or “Full High-Definition”.

Technically speaking, progressive scan 1080p is superior to interlaced scan 1080i, but HD-DVD and Blu-ray discs are currently the only sources of HD 1080p content. Nowadays, some video contents in 1080p format also available in Apple Quicktime Movie Trailer and WMV HD Content Showcase.