Why is Full HD Considered 1080p Despite 1080i Being Common Too?

The term 'Full HD' is often mistakenly associated solely with the resolution of 1080p, especially when everything is actually broadcasted at 1080i. So, why is this the case? This article will explore the differences between 1080p and 1080i, why some systems prefer 1080p, and the historical context behind these display technologies.

The Technical Difference Between 1080p and 1080i

Firstly, it is important to understand the technical differences between 1080p and 1080i resolutions. 1080p stands for 1921080 pixels displayed in a progressive manner, meaning the entire image is refreshed at each frame. 1080i, on the other hand, stands for 1921080 interlaced, where the image is refreshed in two alternating fields. One field contains every other line of pixels, and the next field completes it, resulting in a fully refreshed image every 60 or 50 frames (24 for progressive).

Advantages of 1080p

While both resolutions share the same pixel resolution, 1080p is generally preferred for its improved image quality, particularly for high-motion content like sports or action movies. This is due to the progressive scan method, which provides a smoother and cleaner image with less flicker and more detail. For instance, in high-motion scenes, 1080p can display more frames per second, leading to a more pleasant visual experience without noticeable artifacts.

Why 1080i is Still Used

Despite the advantages of 1080p, 1080i is still used in some traditional broadcast formats, especially where bandwidth is a limiting factor. In these cases, interlaced scanning can significantly reduce the amount of data that needs to be transmitted, making it a more cost-effective solution. However, this does not undermine the importance of 1080p as a high-resolution format.

History and Evolution of Film and Television Technologies

The premise of the question is based on incorrect information. 1080i is every bit as 'Full HD' as 1080p. In fact, the development of television and film technologies has a rich history that should be considered. For a long time, these two industries were separate, with different production technologies. The way flat panel TVs work is such that anything that is p (progressive) is displayed just like a film cell from a movie projector. The entire image is shown at once, eliminating flicker and providing a more natural viewing experience.

Historically, when moving from film to video, there was a need to reduce the data transmission requirements. In the case of interlaced display (i), only half-resolution images were sent every 60th or 50th of a second, followed by the partner half 1/60th of a second later, effectively creating a single full-resolution image every 30th of a second. This method halved the bandwith requirements, making it a practical solution for certain applications.

It’s important to remember that these technologies evolved over time, and the preference for one over the other depends on the specific application, bandwidth availability, and the desired viewing experience. Anyone who proclaims that only 1080p is Full HD is mistaken. It is possible to take a 1080p video file, interlace it, broadcast it as 1080i, and then deinterlace it back to 1080p, resulting in an image that looks exactly the same as the original.

Conclusion

In summary, the distinction between 1080p and 1080i is not just about resolution; it’s about the way the image is scanned and transmitted. Both formats are Full HD, and the choice between them depends on the specific needs of the application. Understanding the history and technical differences behind these formats can help clarify why 1080p is considered Full HD, even though 1080i is still widely used in certain contexts.