What is a pixel

Question 1: What does pixel mean? Pixel is the most basic unit of a picture or photograph. Enlarge a photo, for example, enlarge the photo with a picture viewing software such as "Magic Hand of Light and Shadow", and then enlarge it to a certain extent, and you will see that this photo is originally composed of countless unconnected "points" with different shades of color. These points are the pixels that make up this photo.

The denser the pixel distribution, the more subtle details of the object can be represented as arcs. So the higher the pixels of a photo, the finer the photo. The lower the pixel, the rougher the photo, and many details are difficult to show.

The image of a digital camera is generated by the camera's photosensitive device. Due to the size of the photosensitive device, when the size of the photosensitive device is fixed, pixels that are too high and too dense will cause "interference" between each other, which is not conducive to improving the clarity of the image. For home digital cameras, the size of photosensitive devices is limited. Some manufacturers often take pixels as gimmicks, trying to improve the quality of their products with high pixels. In fact, they didn't increase the size of the photosensitive device (which would increase the cost of the product! ), blindly increasing pixels is not good for improving image quality. Ordinary consumers must not be fooled by this kind of advertisement of merchants!

Question 2: What are pixels and resolution? In order to display various images on a fixed screen, it is necessary to decompose the screen into many small units and change the image content of the small units, which together change the content of the whole screen. Otherwise, fixed the picture can only be displayed on the screen. Fine cells should be too small to be distinguished by the naked eye. This tiny unit is called a pixel.

The number of pixels in the horizontal direction of the screen is called horizontal resolution. The number of pixels in the vertical direction of the screen is called vertical resolution. Usually expressed as

Horizontal resolution x vertical resolution, for example, 1280 x 1024.

Question 3: What are photo pixels? The pixel value is the unit used to calculate the digital image, and its value is equal to the horizontal pixel number multiplied by the vertical pixel number of the picture. For example, a picture of 1600× 1200 has a pixel value of1600×1200 = 2 million. This hint means that your photo is too small, and it has nothing to do with the color.

Question 4: What is resolution? What's the difference between pixel and pixel? Simply put, resolution refers to the number of pixels per unit length, and its unit is usually pixels per inch (ppi). For a screen with a resolution of 1024×768, that is, each horizontal line contains 1024 pixels, * * * has 768 rows, that is, the number of scanning columns is 1024 and the number of rows is 768. The resolution is not only related to the size of the display, but also affected by factors such as the distance between picture tubes and video bandwidth. Among them, it is closely related to refresh frequency. Strictly speaking, the highest resolution that a display can achieve is the highest resolution of this display only when the refresh frequency is "flicker-free refresh frequency".

Definition of pixel: pixel refers to the basic coding of gray level of basic original pigment Dan. It consists of the letters of the words Picture and Element, and is the unit used to calculate digital images. 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 "pixels" that make up the image. This smallest graphic unit can usually display a coloring point on the screen. The higher the pixel, the richer the sample and the more realistic the color is.

Question 5: What is the pixel value of13 million pixels?

The pixel mentioned by the camera actually refers to the maximum pixel, which is the unit of resolution. This pixel value is only the effective maximum resolution supported by the camera.

300,000 640×480

500,000 800×600

806,5438+0024× 768 5 inches (3.5× 5 inches)

1.3 million 1.280× 960 6 inches (4× 6 inches)

2 million 1600× 12008 inches (6× 8 inches) 5 inches (3.5× 5 inches)

365438+ million 2048×153610 "(8×10 inch) 7" (5× 7 inch)

4.3 million 2400× 1800 12 inch (10× 12 inch) 8 inch (6× 8 inch)

5 million 2560× 1920 12 inch (10× 12 inch) 8 inch (6× 8 inch)

6 million 3,000× 200014 "(114 inch)10" (8×10 inch).

8 million 3264× 248816 "(12×16 inch)10" (8×10 inch).

1 1 4080× 2720 20 inches (16× 20 inches) 12 inches (10× 12 inches).

144,536× 3024 24 inches (18× 24 inches) 14 inches (1 1× 14 inches).

All the above are approximate sizes.

"Pixel" consists of letters of the words "picture" and "element" and is used to calculate digital images.

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.

A square point is the smallest unit "pixel" that constitutes an image. This smallest graphic unit can usually display a coloring point on the screen. The higher the pixel, the richer and more samples.

Can express the realism of color.

Question 6: What is a pixel? What is a vector? Simply put, it is a pixel map, also called a bitmap. If you enlarge it a lot, it will be called a pixel. As for the vector map, no matter how many times you enlarge it, it will not be distorted.

1, vector diagram

Vector diagram, also called vector diagram, describes and records a graph with a series of computer instructions. A graph can be decomposed into a series of subgraphs composed of points, lines and faces. It records the geometric shape, line thickness and color of the object. The storage capacity of the generated vector diagram file is very small, which is especially suitable for text design, pattern design, layout design, logo design, computer-aided design (CAD), arts and crafts design, illustrations and so on.

Vector drawings can only represent figures composed of regular lines, such as engineering drawings, three-dimensional modeling or artistic words; For images (landscapes, figures, mountains and rivers) composed of irregular pixels, it is difficult to express them in mathematical form, so it is not suitable to use vector diagram format; Secondly, vector diagram is not easy to make colorful images, and the drawn images are not very real, which is not convenient for exchanging data between different softwares.

In addition, vector images cannot be obtained by scanning, and are mainly generated by design software. The vector drawing program defines (like mathematical calculation) the angle, arc, area and spatial direction relative to the paper, including the wireframe giving the filling and wheel features. Common vector graphics processing software includes CoreIDRAW, AutoCAD, Illustrator, FreeHand and so on.

Step 2 Bitmap

Bitmaps are also called bitmaps or pixel maps. The map on the computer screen is made up of luminous points (pixels) on the screen. Each point uses binary data to describe its color and brightness. These points are discrete, similar to a lattice. The tones of multiple pixels form an image, which is called a bitmap.

When the bitmap is enlarged to a certain extent, it will be found that it is composed of small squares, which are called pixel points, and a pixel is the smallest image element in the image. When dealing with bitmap images, pixels are edited instead of objects or shapes, and their size and quality depend on the number of pixels in the image. The more pixels per square inch, the clearer the image and the smoother the color mixture. Computer storage of bit images actually stores information such as the position and color data of each pixel of the image, so the clearer the image, the more pixels there are, and the greater the corresponding storage capacity.

Compared with vector images, bitmap images are more likely to imitate the real effect like photos. The main advantages of bitmap images are strong expressive force, delicacy, multi-level and many details, which can easily simulate the real effect like photos. Because the pixels in the image are edited, the clarity and smoothness of the image will be affected when the image is stretched, enlarged or reduced. Bitmap images can be obtained by digital camera, scanning or PhotoCD, and can also be generated by other design software.

Bitmap images, also known as dot matrix images or drawn images, are composed of individual points called pixels. When you enlarge the bitmap, you can see the picture elements that make up the image. Expanding the bitmap size means adding a single pixel, which will make the lines and shapes appear uneven. But if you go further,

From the position, the color and shape of bitmap images are continuous, which is the characteristic of bitmap. Vector images, also known as drawing images, are mathematically defined as a series of relationships between points. Vector image can be enlarged or reduced at will, and the image will not be distorted.

Question 7: What is the concept of pixel? What is the concept of resolution? Pixel:

baike.baidu/view/575? WTP = TT

Resolution:

baike.baidu/view/7687

It's all in there!

O(∩_∩)O

Question 8: What is a pixel? Resolution is a parameter used to measure the amount of data in a bitmap image, usually expressed in pixels. Simply put, the resolution of the camera refers to the ability of the camera to analyze images, that is, the number of pixels of the camera's image sensor. The highest resolution refers to the size of the camera's ability to distinguish images at the highest level, that is, the maximum number of pixels of the camera. At present, the maximum resolution of 300,000-pixel CMOS on the market is generally 640,480 pixels, and the maximum resolution of 500,000-pixel CMOS is generally 800,600 pixels. The two digits of the resolution represent the point units of the length and width of the picture. The aspect ratio of digital pictures is usually 4: 3.

In practical application, the higher the pixel of the camera, the better the image quality, but conversely, the higher the pixel, the better. The higher the pixels of the same picture, the stronger its ability to analyze the image, but the amount of data it records will be much larger, so the requirements for storage equipment are much higher.

In fact, these camera pixels are all improved by software interpolation. For example, to put it simply, the 640X480 picture is enlarged to 1024X768, and then the color difference between the resolution points of the picture is calculated by software, and the middle enlarged part is filled with the color calculated by software. Although the output image is large, the image quality has not been really improved effectively, and even serious distortion may occur.

It is worth noting that some resolution marks refer to the interpolation resolution that these products can achieve by using software. Although it can also improve the accuracy of image acquisition, there is still a certain gap compared with the hardware resolution.

Therefore, when you buy a camera, you must remember that there is no absolute relationship between the pixel level of the camera and the clarity of the image. Especially those cameras with hundreds or even tens of millions of pixels interpolated by software, the actual effect is likely to be similar to hundreds of thousands of pixels. Generally speaking, whether the image is clear or not depends on the pixels, but it is also closely related to the lens material and software processing.

Some technical indexes of cameras

1, image resolution/resolution:

SXGA( 1280 x 1024) is also called 1.3 million pixels.

XGA( 1024 x768) is also called 800,000 pixels.

SVGA(800 x600) is also called 500,000 pixels.

VGA(640x480) is also called 300,000 pixels (350,000 refers to 648X488).

CIF(352x288) is also called 65438+ megapixels.

SIF/QVGA(320x240)

QCIF( 176x 144)

QSIF/QQVGA( 160x 120)

2. Image format/color space.

RGB 24 and I420 are the two most commonly used image formats at present.

RGB 24:R, G and B have 8 bits each, which can represent 256 colors at most, so that 256*256*256 colors can be reproduced.

I420: One of YUV formats.

Other formats are: RGB565, RGB444, YUV4:2:2, etc.

National football and camera: the national football is not credible, but sometimes it has to be watched; Camera pixels are even more unreliable, and sometimes you have to buy them! In a word, keeping your eyes open and choosing rationally is the best choice at present.

Question 9: What exactly does the so-called pixel mean? "Pixel" consists of letters of the words "picture" and "element", which is the unit used to calculate digital images. Just like photos, digital images 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 "pixels" that make up the image. This smallest graphic unit can usually display a coloring point on the screen. The higher the pixel, the richer the sample and the more realistic the color is. Pixel is usually considered as the smallest complete sample of an image. This definition is very relevant to the context. For example, we can say that pixels in a visible image (such as a printed page) are pixels represented by electronic signals, pixels represented by numbers, pixels on a display or pixels in a digital camera (photosensitive element). Many other examples can be added to this list. Depending on the context, there will be some more accurate synonyms, such as pixels, sampling points, bytes, bits, dots, spots, supersets, triples, edge sets, windows and so on. We can also discuss pixels abstractly, especially when using pixels as a measure of resolution, such as 2400 pixels per inch (ppi) or 640 pixels per line. Dots are sometimes used to represent pixels, especially computer marketers, so ppi is sometimes written as DPI (dots per inch). The more pixels used to represent an image, the closer the result is to the original image. Although there is a more specific definition of resolution, the number of pixels in an image is sometimes called image resolution. Pixels can be represented by a number, such as a 3-megapixel digital camera with a rated pixel of 3 million, or by a pair of numbers, such as a "640 by 480 display" with 640 pixels in the horizontal direction and 480 pixels in the vertical direction (just like a VGA display), so its total number is 640× 480 = 307,200 pixels. The color sampling points of digital images (such as JPG files commonly used in web pages) are also called pixels. Depending on the computer monitor, these pixels may not have a one-to-one correspondence with the screen pixels. In this obviously different area, the points in the image file are closer to the texture elements. In computer programming, an image composed of pixels is called a bitmap or raster image. Grating once originated from analog TV technology. Bitmap images can be used to encode digital images and some types of computer-generated art.