Know the resolution of the computer (on)

Mentioning the resolution, this may be a concept that most computer enthusiasts pay less attention to, because most enthusiasts would rather spend time on researching the overclocking ability of the motherboard or processor and updating the graphics card, etc. This is the opinion of my family. Some biased, well, the following into the topic, in fact, the resolution is an important concept related to the image, it is a technical parameter to measure the performance of image details. However, there are many kinds of resolution and their meanings are different. Correct understanding of the specific meaning of resolution in various situations and clarifying the relationship between different representation methods is a crucial step. The following describes several common image input/output resolutions and different image input/output device resolutions for your reference.

Image Resolution

Image Resolution: The amount of information stored in an image. There are several ways to measure this resolution, typically measured in pixels per inch (PPI). The resolution of the image and the value of the image size together determine the size of the file and the quality of the output. The larger the value, the more disk space the graphics file occupies. The image resolution affects the size of the file in a proportional relationship, ie the file size is proportional to the square of its image resolution. If you keep the image size unchanged, double the image resolution, and then increase the file size by four times.

Scan resolution

Scanning resolution: refers to the resolution set before scanning an image. It will affect the quality and performance of the generated image file. It determines how the image will be displayed or printed. If the scanned image is used for a screen display of 640 x 480 pixels, then the scanning resolution does not have to be greater than the device resolution of a typical display screen, ie generally not exceeding 120 DPI.

However, in most cases, images are scanned for output in high-resolution devices. If the image scanning resolution is too low, the output will be very rough. Conversely, if the scanning resolution is too high, the digital image will produce more information than needed for printing, which not only slows down the printing speed, but also causes a slight transition of the image tone to be lost during the printout.

Under normal circumstances, the image resolution should be twice the screen frequency, which is currently the standard adopted by most output centers and printing plants in China. However, in reality, the resolution of the image should be 1.5 times the screen frequency. I am afraid that there will be controversy on this issue. However, the actual situation is different in different images.

Screen resolution

Screen Resolution: Also known as screen frequency, refers to the number of dots per inch on the screen used to print gray scale images or color separation images. This resolution is expressed in lines per inch (LPI).

Bit resolution of the image

Image Bit Resolution (Bit Resolution): Also known as bit depth, is used to measure the number of bits of information stored in each pixel. This resolution determines the likelihood of how many color levels can be marked. Commonly there are 8-, 16-, 24-, or 32-bit colors. Sometimes we also refer to bit resolution as color depth. The so-called "bit" actually refers to the squared number of "2", 8 bits is 2 to the 8th power, that is, 8 2 multiplication, equal to 256. Therefore, an 8-bit color depth image can represent 256 levels of color.

Device resolution

Device Resolution: Also known as output resolution, refers to the number of dots per inch that can be produced by various types of output devices, such as the resolution of displays, inkjet printers, laser printers, and plotters. This resolution is measured by DPI, which currently has a device resolution of 60 to 120 DPI. The print device resolution is between 360 and 1440 DPI.