What do 4k and HD mean on the camera?

4K refers to the resolution of the image, which means that the pixel value of each line in the horizontal direction reaches or approaches 4096, and in most cases it refers to the resolution of 4096*2 160.

According to the different application scope, there are various derivative resolutions of 4K resolution, such as 4096 * 312 for full aperture 4K, 3656*2664 for 4K Academy of Sciences and 3840*2 160 for UHDTV standard, all of which belong to the category of 4K resolution.

HD is the abbreviation of high definition, which means high definition and high image quality. Refers to an image or video with a vertical resolution greater than or equal to 720, also known as high-definition image or high-definition video.

Extended data

The most obvious performance of 4K technology lies in the improvement of its display resolution, which makes the picture more detailed. There are two key factors that affect the fineness of the picture, one is the pixel of the picture, and the other is the vertical resolution of the picture. The higher the pixels in a picture, the finer the pixels and the smaller the grid in a picture of the same size.

Because the human eye is quite sensitive to the vertical resolution of the image, the higher the vertical resolution, the more details and levels the human eye can recognize. What 4K technology can do in the field of monitoring is to enhance the vertical resolution of the picture and make the details and levels of the picture more accurate while improving the pixels.

Secondly, the enhancement of color levels and details makes the picture closer to real life. In fact, the change from standard definition to high definition display system is mainly the upgrade of resolution, and there is no obvious improvement in color.

However, in the era of 4K Ultra HD, besides the leap of resolution, the change of color is particularly noticeable. This split appears in the latest ITU-R BT.2020 ultra-high definition broadcasting standard.

Finally, the 4K video system processes video signals encoded with 10 bits or even 12 bits. At present, high-definition or full-high-definition systems usually adopt 8-bit video systems, while 4K ultra-high-definition systems adopt 10 or even 12-bit video systems. Therefore, both the gradation transition and the gradation expression of color depth are greatly improved compared with the high-definition system.

Baidu Encyclopedia -4K Resolution

Baidu Encyclopedia-HD