Practical Method of Using Scanner I
Do you know how to use scanners? Then, how? If you want to know the practical method, you must have a good look at the following content!
Scanner is a device that uses photoelectric technology and digital processing technology to convert graphic or image information into digital signals by scanning.
Scanners are usually used for instruments and equipment external to computers. By capturing images and converting them into digital input devices that computers can display, edit, store and output. The scanner can be used to scan photos, text pages, drawings, art pictures, photographic negatives, film films, and even three-dimensional objects such as textiles, sign panels, printed board samples, etc. and to extract and convert original lines, graphics, text, photos, and planar objects into devices that can be edited and added to files. The scanner belongs to the input system of computer aided design (CAD). Through computer software and computer, the interface of output equipment (laser printer, laser plotter) forms the computer processing system before screen printing. It is suitable for office automation (OA) and is widely used in sign panel, printed board, printing industry, etc.
How to use scanner
(1) Determine the appropriate scanning mode
Scanners can be used to scan images, text, photos, etc. Different scanning objects have different scanning methods. Opening the scanner's drive interface, we found that the program provides three scanning options, of which the "black and white" method is applicable to documents in black and white. The scanner will represent black and white pixels by one bit, thus saving disk space. "Grayscale" is applicable to mixed layout of pictures and texts with both pictures and texts，scanning this type of pictures with both texts and multiple grayscale levels. "Photos" is suitable for scanning color photos. It requires multi-level sampling and storage of red, green and blue channels. Before scanning, it is necessary to select an appropriate scanning method according to the scanned object before obtaining a higher scanning effect.
(2) Optimizing scanner resolution
The higher the scan resolution is, the clearer the image is. However, considering that if the resolution of the output device is exceeded, it is impossible to print the clearer image. It only takes up more disk space and has no practical value. Therefore, it is necessary to choose the appropriate scan resolution. For example, prepare to use a 600dpi resolution printer to output the results and scan at 600dpi. If possible, scale down large images after scanning. For example, if you scan a 4*4-inch image at 600dpi and reduce it to 2*2 inches in the editing program, its resolution is 1200dpi.
(3) Set the scanning parameters
When a scanner pre-scans an image, it scans according to the system default scanning parameter values. For different scanning objects and different scanning methods, the effect may be different. Therefore, in order to obtain higher image scanning quality, the parameters can be adjusted manually. For example, when the brightness of gray scale and color images is too bright or too dark, the brightness can be changed by dragging the slider on the brightness slide bar. If the brightness is too high, the image will look white. If the brightness is too low, it is too dark. The brightness of the image should be moderate when dragging the brightness slider. Similarly, for other parameters, local modifications can be made according to the same adjustment method until their visual effects are satisfactory. In a word, a good scanned image can meet the printing output without further adjustment in the image processing software, and is closest to the printing quality..
(4) Set the file size
No matter whether the scanned object is text, image or photo, it is an image after being output by the scanner, and the size of the image is directly related to the size of the file capacity, so the size of the file should be set during scanning. Usually, the scanner can automatically calculate the file size when previewing the original manuscript sample, but knowing how to calculate the file size is more helpful for you to make appropriate choices when managing scanning files and determining the scan resolution. The calculation formula of binary image file is: horizontal dimension x vertical dimension x (scan resolution) 2/8. The calculation formula of color image file is: horizontal dimension x vertical dimension x (scan resolution) 2×3.