Essay on the Hdtv
HDTV Television - An Introduction
Two lectures of material
I. The movement toward HDTV
The original impetus for HDTV came from wide-screen movies. Soon after wide-screen was introduced, movie producers discovered that individuals seated in the first few rows enjoyed a level of participation in the action not possible with conventional movies. Evidently, having the screen occupy a great field of view (especially peripherally) significantly increases the sense of "being there".
Early in the 1980s, movie producers were offered a high-definition television system developed by Sony and NHK in the late 70s. This system (called NHK Hi-vision) and its variants are capable of producing images having essentially the same detail as 35 mm film[1]. With these systems, a scene could be recorded, played and edited immediately, and then transferred to film. As a consequence, many of the intermediate delays in conventional film production were eliminated. The new medium also offered a number of possibilities for special effects not possible in conventional film production.
Following the introduction of HDTV to the film industry, interest began to build in developing an HDTV system for commercial broadcasting. Such a system would have roughly double the number of vertical lines and horizontal lines when compared to conventional systems.
Now, the most significant problem faced with HDTV is exactly the same problem faced with color TV in 1954. There are approximately 600 million television sets in the world and approximately 70% of them are color TVs. An important and critical consideration is whether the new HDTV standard should be compatible with the existing color TV standards, supplant the existing standards, or be simultaneously broadcast with the existing standards (with the understanding that the existing standards would be faded out over time).
There is precedence for both compatibility and simultaneous broadcast. In 1957, the US chose compatibility when
Two lectures of material
I. The movement toward HDTV
The original impetus for HDTV came from wide-screen movies. Soon after wide-screen was introduced, movie producers discovered that individuals seated in the first few rows enjoyed a level of participation in the action not possible with conventional movies. Evidently, having the screen occupy a great field of view (especially peripherally) significantly increases the sense of "being there".
Early in the 1980s, movie producers were offered a high-definition television system developed by Sony and NHK in the late 70s. This system (called NHK Hi-vision) and its variants are capable of producing images having essentially the same detail as 35 mm film[1]. With these systems, a scene could be recorded, played and edited immediately, and then transferred to film. As a consequence, many of the intermediate delays in conventional film production were eliminated. The new medium also offered a number of possibilities for special effects not possible in conventional film production.
Following the introduction of HDTV to the film industry, interest began to build in developing an HDTV system for commercial broadcasting. Such a system would have roughly double the number of vertical lines and horizontal lines when compared to conventional systems.
Now, the most significant problem faced with HDTV is exactly the same problem faced with color TV in 1954. There are approximately 600 million television sets in the world and approximately 70% of them are color TVs. An important and critical consideration is whether the new HDTV standard should be compatible with the existing color TV standards, supplant the existing standards, or be simultaneously broadcast with the existing standards (with the understanding that the existing standards would be faded out over time).
There is precedence for both compatibility and simultaneous broadcast. In 1957, the US chose compatibility when