What do you mean by how many P's are behind the picture?

How many P's are behind a picture is the vertical pixel number of a picture. For example, the same image has the same size, but the resolution is different, so the size is different.

An image consists of points, and a column contains 720 points or 1080 points, which is the difference between 720P and 1080p.

According to the definition, pixel refers to the basic primary color pigment and the basic coding of its gray level.

Pixel is the basic unit of digital image, and the resolution of image is usually expressed by PPI per inch.

For example, a resolution of 300x300PPI means that the number of pixels per inch is 300 both horizontally and vertically, or it can mean that there are 90,000 (300x300) pixels per square inch.

Like photographic photos, digital images also have continuous shadows. If you enlarge the image several times, you will find that these continuous tones are actually composed of many small squares with similar colors, which are the smallest unit of the image-pixels.

This smallest graphic unit usually displays a single coloring point on the screen. The higher the pixel, the richer the sample and the more realistic the color is.

Generally speaking, in a movie, the size of the picture is 704×304, which can be understood as a picture with so many pixels. And 720P and 1080P are high-definition standards, that is to say, 720 lines are vertical and 1080 lines are scanned line by line.

"P" and "I" are different. If it is 1080I, it is interlaced scanning. The effect is not as good as 1080p, but better than 720P. Moreover, high definition requires high machine performance. 1080P requires a 23-inch or 24-inch LCD screen to watch point-to-point. The cpu frequency is probably above 3G, or there is a hardware decoding graphics card.

720P, generally 1280×720, sometimes the picture is very long. What kind of widescreen movie is it? Horizontal direction 1280, vertical direction less than 720. 1080p: generally 1920× 1080.

Extended data:

1080i and 720p are internationally recognized standards for digital HDTV. The original NTSC countries adopted the format of 1080i/60hz, which is the same as the field frequency of NTSC analog TV. While some countries adopting PAL system, such as Europe and China, adopt 1080i/50hz mode, and the field frequency is the same as PAL analog TV.

As for 720p, IT has become an optional standard due to the deeper penetration of IT vendors into the TV industry. At present, it has begun to expand its territory in the field of high-definition TV players based on optical discs.

When using mobile phone camera equipment or digital camera equipment, we can generally adjust the resolution and proportion of photo imaging. We generally use the above criteria to describe our resolution.

1080p is the actual standard, but 1080p is not the standard currently used in the civil field. 1080p not only has a field frequency of 60Hz, but actually three field frequency specifications of 24Hz, 25Hz and 30Hz are the most widely used.

We know that movies play movies at a speed of 24 per second. Digital images shot in 1080p/24hz mode can be transmitted to digital film projectors such as DLP/D-ILA without loss, and played in film format. 1080p/24hz is the format of the movie.

If the HD content is shot in the format of 1080p/25hz, each frame of the complete 1080p image can be easily split into two interlaced 1080i images. In this way, the format of 1080p/25hz becomes an image of 1080i/50hz, which is convenient to be applied to digital HDTV in Europe and China.

References:

Baidu encyclopedia-pixel