Blu-Ray picture quality

The real big difference between DVD and Blu-Ray is the great picture quality Blu-Ray offers. There are several parameters that determine the perceived image quality of digital sources and in this part of the guide you get an explanation of these.

Resolution
Blu-Ray supports a variety of resolutions from the usual standard SD resolution to 1920 x 1080 pixels. The solution that is used on movies is 1920 x 1080 pixels (2 mega pixel), where the film is stored at 24 frames per second (1080p / 24) which is exactly the number that movies are recorded with. In relation to DVD gives far more detail and better depth.

Almost all televisions and projectors fully support this resolution. The image below illustrates the difference in resolution between Blu-Ray and DVD.

Blu-Ray has 5x higher resolution than DVD. How well this difference appears depends on how big TV (or projector screen) one has and how far away the picture you are sitting. In addition difference shows best on devices with Full-HD resolution, but also on devices with HD-ready resolution will notice good difference if the size is large enough or sitting close enough.

Video codec
In addition to higher resolution, Blu-Ray support for more modern compression standards. In addition to MPEG2 which is what DVD using supports Blu-Ray VC1 and MPEG4 AVC codecs. These highly efficient codecs makes it possible to store film in HDTV quality in less space than is possible using MPEG2. The first movies on Blu-ray were released with MPEG2 decoding in addition to that they were released on 25GB discs

VC1 codec developed by Microsoft and is regarded by many as the most effective. The latest Blu-ray releases largely use AVC and VC1 codecs on 50GB discs.

Bitrate
Blu-Ray supports a bitrate of up to 40 Mbit / s on the image (48 with sound), which in combination with VC1 / AVC allows for very good image quality. The average videobitraten movies released on Blu-Ray is between 17 to 23 Mbit / s. Bitrate of the different films will typically vary based on the length of the film, whether it is double or widow tier release, the codec used and what lydystem (s) film has. If the movie is long must bitrate is reduced so that the film can fit.

Colour Depth
The color depth describes the number of colors that can display format. Blu-Ray has 8 bit color depth per basic color (red, green and blue) and this gives an opportunity to 16.8 million different colors. This is the same color depth as DVD and HD DVD has. This is an important element for those who believe that HDMI version 1.3 which supports greater color depth than 8 bit, will provide a better picture. Unless you have no sources with greater color depth is HDMI version 1.3 no argument for image quality.

Below you can see a comparison between a screenshot from Blu-Ray release of Black Hawk Down and DVD release upscaled to 1080p.

• ← Previous
• Neste →

Annonse