Introduction to High Definition Video and Its History [MiniTool Wiki]
Introduction to High Definition Video
What is high definition? A video with higher resolution and quality than standard-definition is called high definition video (HD video). Actually, high definition has no standardized meaning, but generally, any video image with more than 480 vertical lines (North America) or 576 vertical lines (Europe) is considered high definition.
Keep reading, then you can know more information about the high definition from this post offered by MiniTool.
The 480 scan lines are usually the minimum, even though most systems greatly exceed that number. In some cases, standard resolution images captured by high-speed cameras at rates faster than normal speeds (60 frames per second in North America and 50 fps in Europe) may be considered high definition.
To make some TV series shot on high-definition video look like they were shot on film, this technique is often called filmizing.
The History of High Definition
The first high definition TV system was the first electronic format – 405 lines. Beginning in 1939, Europe and the United States tried to use 605 and 441 lines. It was not until 1941 that the FCC mandated the use of 525 lines for the United States.
In wartime France, René Barthélemy tested a higher resolution, up to 1,042. At the end of 1949, the French official transmission finally began at 819. However, in 1984, the standard for 625 lines of color on the TF1 network dropped.
Modern HD specifications date back to the early 1980s when Japanese engineers developed the HighVision 1,125-line interlaced TV standard (also known as MUSE) running at 60 frames per second. In Algiers, April 1981, the Sony HDVS system was released at an international conference of television engineers. And in 1983, Japan's NHK presented its analog high definition television (HDTV) system at a Swiss conference.
The NHK system was standardized in the United States in the early 1990s as the Society of Motion Picture and Television Engineers (SMPTE) standard # 240M but was later replaced by the DVB analog standard.
Due to unrealistically high memory and bandwidth requirements, high-definition digital video cannot be achieved for uncompressed video and bit rates in excess of 1 Gbps for full-HD video. Digital high definition television is realized through the development of discrete cosine transform (DCT) video compression.
North America's current high definition video standard was developed during the 1987 advanced television process initiated by the Federal Communications Commission at the request of the American broadcasters. Essentially, the late 1980s was a death knell for most of the analog high definition technology that had been developed at the time.
The FCC process led by the Advanced Television Systems Committee (ATSC) used a range of standards, including interlaced 1,080-line video (the technical offspring of the original analog NHK 1125/30 Hz system) with a maximum frame rate of 30 Hz (60 fields per second) and 720 lines of video, progressively scanned, with the maximum frame rate of 60 Hz.
However, in the end, the DVB standard for resolutions (1080, 720, 480) and corresponding frame rates (24, 25, 30) was adopted with Europeans who were also participating in the same standardization process. The FCC officially adopted the ATSC transmission standard (including HD and SD video standards) in 1996, and first broadcasted on October 28, 1998.
In the early 2000s, it seemed that DVB would become the video standard of the future. However, both Brazil and China have adopted an alternative standard for high definition video that has ruled out the interoperability that decades of largely inoperable analog TV broadcasters had hoped for.
High Definition Content
High-definition image sources involve video game consoles, high-definition discs (BD), direct broadcasting satellites, digital cables, digital cameras, Internet downloads, and terrestrial broadcast.
Most computers can achieve HD or higher resolutions via VGA, DVI, HDMI and/or DisplayPort. The optical disc standard Blu-ray Discs provide enough digital storage space to store hours of high-definition video content. But Digital Versatile Discs or DVDs (4.7 GB in a single layer or 8.5 GB in a double layer) do not always meet the challenges of today's high-definition (HD) televisions.
To sum up, after reading this post, you may have known some information about high definition. It has experienced several processes until it is used in our daily life.