Resolution Analysis of Book Scanner
The book scanner is a kind of computer input equipment that can input image data into the computer. Pictures, photos, films, drawings and all kinds of documents can be input into the computer by the scanner and stored in the form of pictures. Some people vividly call Book scanners "the eyes of computers". Document management is the most widely used field of scanners.
The book scanner can also cooperate with optical character recognition software OCR (optical character recognition) to convert scanned documents into computer text form. It omits a lot of manual input time.
The concept of scanner resolution: scanner resolution is divided into optical resolution and maximum resolution. The maximum resolution is equivalent to the interpolation resolution and does not represent the true resolution of the scanner. Therefore, when we purchase scanners, we should take the optical resolution as the judgment standard.
The resolution unit of the scanner is DPI. The maximum optical resolution of the scanner is multiplied by two numbers, such as 600 × 1200 DPI (also known as 600 × 1200 line). The former number represents the lateral resolution of the scanner, i.e. optical resolution, which is determined by the CCD performance of the scanner. The latter number represents the vertical or mechanical resolution of the scanner, which is the resolution of the stepper motor used by the scanner. When judging the optical resolution of the scanner, we should take the smallest one as the criterion.
Resolution is the main technical index of the scanner. It represents the ability of the scanner to show the details of the image, which determines the fineness of the image recorded by the scanner. The higher the resolution of scanning, the higher the quality of the scanning image, but there are limits. When the resolution is greater than a certain value, it will only make the image file larger and not easy to process, and it will not significantly improve the image quality.
In practice, the higher the resolution setting, the larger the scanned file, and the slower the scanning speed, which is not convenient for management and saving. Therefore, we seldom use the highest resolution of the scanner in actual scanning. We need to use different resolutions according to the nature of the document. The general settings are as follows:
A. In the category of photos, the reso lution of 350-400 is adopted, some of which are particularly important, and even the resolution of 600 or higher can be adopted.
B. Detection report, business license, code certificate, etc., with 300 resolution.
C. Some important documents (such as archives, files, ancient books, books, etc.) adopt 300 resolution.
D. The resolution of 300 shall be adopted for engineering visa documents.
E. General contract text, text records, etc., with a resolution of 150 to 200.
Therefore, when choosing a scanner, the scanner with 600 resolution has fully met the requirements, because in general, we can use up to 300-400 resolution. Use 600 resolution in special cases.
When the book scanner is in use, the scanning range can be adjusted by dragging the mouse, and the resolution can be set according to the needs, so the operation is very simple.