Key Features

A scanner is a device designed to enter digital information from print media, photographs and drawings. The quality of the files and the speed of their processing depend on the quality of information transfer of this device.

Scanner specifications

Printed information using special computer programs can be converted into text files. The speed and accuracy of character recognition depends on the quality of the original, which in turn depends on the characteristics of the scanner.

Optical resolution

This setting is fundamental in the scanning characteristics. It is expressed by the number of dots that fit in the 1st inch, a value of approximately 2.54 cm, and is indicated by dpi. The devices are widely used using a resolution of 100 - 200 dpi. Such permission is considered low. From 300 dpi - medium resolution. Starting at about 1200 dpi, this setting is considered high. Such quality should have copies working with photographs, but this will not be enough for professionals.

There is also such a thing as mechanical resolution. This parameter determines the mechanical pitch of the scan head carriage. It can be equal to the optical one, but usually larger and a multiple of 2. Its value also indirectly affects the quality of the processed materials, but do not confuse it with the optical one, on which the image sharpness directly depends.

Interpolation resolution is an increased image clarity programmatically. Rather, the resolution obtained after the software revision, a kind of “completing” vague microobjects. It is usually 16 times higher than described.

IMPORTANTWhen choosing and purchasing the right device, you need to know that the main quality of the scanned document or photograph will be determined precisely by optical, and not by any other resolution.

It is also important to know that with subsequent software image processing, resolution is better used as a multiple of optical. Then it is possible to minimize interpolation distortion. When converting photographs and documents, this parameter must be taken into account, which will minimize compression errors. For example, the scanner has a resolution of 1,600 dpi, and 250 dpi is enough for us. Then it is better to convert to 266 dpi, which will be a multiple of the 6-basic resolution of the scanner.

Color depth

For technical documents that will subsequently be converted to text format, this option is of very little importance. But for scanning photos, this option is important. It is determined by the number of bits. In black and white, it is 1, in low-quality - 8. Although the image with such a depth of color looks beautiful. Computer programs work mainly with a color depth of 24 bits. But it is better if the device produces a little more depth. This will reduce the amount of color noise.

There are also concepts of external and internal color depth. The external depth determines the number of colors transmitted through the interface. Usually this parameter is decisive. The internal depth is the ability of the sensors themselves to recognize colors. It is usually more basic to reduce noise, and is not critical.

Dynamic range

This parameter has a logarithmic dependence of the intensity of the supply light to the scanned surface and reflected from it. It is characterized by a spread of brightness and is measured in D. The maximum number is 4.0 D - corresponds to the perfectly black position of the brightness. This parameter also depends on the capacity of the system. For scanners with 30-bit resolution, the maximum dynamic range coefficient is 3.0 D, for 36-bit - 3.6 D. The common 24-bit versions have a range of 1.8 - 2.3 D.

It should be noted that for processing documents calculated for conversion to text formats, it is necessary to choose a scanner with the largest dynamic range. Then even worse quality pages will be recognized faster and come to life on the screens of computers and tablets.

Scan Speed ​​and Software Suite

These indicators are secondary, but can play a small role, especially speed. The speed at which a document or image is scanned can significantly affect performance, especially when it comes to large, constant volumes.

The software that comes with the device is often the most suitable for coordinated work. but if the functionality of the software from the kit is not enough, the user has to apply for a more suitable one. Software with advanced functionality does not always work correctly with a specific scanner model, conflicts begin, work becomes difficult or stops at all.

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