One pixel, short for picture element, is the smallest unit or smallest dot in an image. Thousands or millions of pixels combine to constitute the visual. The resolution is the total number of distinct pixels arranged horizontally and vertically in the image (width x height). The term is used to describe the quality of video content, monitors, displays, screens, etc.
The more pixels the projector fits into the space, the higher the resolution of the image. And higher resolutions mean greater levels of detail.
The most common resolutions today in the high-end projection market are WUXGA, WQXGA, 4K UHD and native 4K.
The aspect ratio refers to the proportional relationship between the width and height of your image canvas. This proportion defines the shape of the image which could be squarer or a wider rectangular.
The two most popular aspect ratios are 4:3, used in early analog television sets and tablets, and 16:9, which is the current international standard for modern televisions and computer displays. In projection, 16:10 is the most common ratio.
4K resolution is a generic term referring to a horizontal pixel count of approximately 4,000 pixels.
We say approximately because there are several different 4K resolutions which are currently common. In television and consumer media, 4K UHD (3840 x 2160 pixels or 3840 x 2400 pixels) is the dominant 4K standard, whereas the digital cinema industry uses the DCI 4K or native 4K standard (4096 × 2160 pixels). The Barco projection portfolio offers both UHD and native 4K systems.
In a projection context 4K UHD typically refers to the use of pixel-shift technology, while native 4K refers to a situation where 4K pixels are available without the use of pixel-shift.
The key benefit of 4K resolution is its capability to display clear, realistic, and detailed visuals. Nonetheless, the best 4K experiences require considerations beyond pixels – from source to output.
There are basically two types of 4K technology. The first one, referred to as native 4K, is the most simple and direct: a 4K input gets processed pixel by pixel to a 4K output. This way, all image information is fed in a direct pipeline from input to output and thus there is no loss of quality nor any compensation for manipulations on that image.
The second technology is what is called pixel-shifting. With pixel-shifting, a native 4K input is broken down into two (or more) lower resolution pixel fields, each containing a subset of pixels of the original 4K image. These two images are then processed through a so-called actuator which very quickly shows the images offset from each other. So, in total, there are 16 million pixels that form a quasi-lossless formation of the 4K UHD image on the screen.
Barco has chosen a unique approach in its quest for the best possible image quality at the lowest latency. We have developed an internal processing system via our Pulse electronics that gathers the necessary information for every pixel, and then processes this information in a single step. The Barco single step processing not only avoids the loss of detail, but also minimizes latency by doing everything in parallel.
When talking about resolution, you can find different labels in your spec sheets. First there are labels like 480p or 720p or 1080p. These numbers refer to the number of pixels in the height of the image. A 1080 resolution picture (at a 16:9 aspect ratio) is 1080 pixels tall and 1920 pixels wide. These labels correspond with the other commonly used names Standard Definition, High Definition and Full High Definition.
The 4K resolution brings another wrinkle in the terminology maze. As we said, the label numbers typically refer to the pixel height of the image, but the 4K name refers to the approximately 4000 pixel-width of the image instead of its pixel height.
The table below summarizes the different labels.