Common Hardware glossary! Absolutely authoritative! (Go !) 11. Scanner Glossary

11. Scanner Glossary
　　
CCD (charge coupler): CCD has developed for a long time, and its technology and manufacturing process have been quite mature. the image quality of CCD scanners is quite prominent and can meet almost all requirements. It mainly uses CCD micro-semiconductor photosensitive chip as the core of the scanner. Using CCD for scanning requires a set of precise optical systems, which makes the scanner structure complex. Therefore, it is characterized by high scanning quality, a wide range of scanning (can scan the physical), long service life, high resolution. The working principle of traditional CCD technology is similar to that of photocopiers. It uses an external high-brightness light source to illuminate the original image. the reflected light of the original image is then imaged on the CCD element after the mirror, the projection mirror and the splitter. Because lens imaging has a clear range, the source can have a certain depth of field, that is, it can scan objects with a three-dimensional surface. The depth of field of CCD scanners can generally reach a dozen centimeters, Which is what vendors often say about 3D scanning. Because CCD optical devices are complex and difficult to reduce the volume, CCD scanners are generally heavy. CCD devices are the same as those used in digital cameras, and the manufacturing technology is very mature. CCD devices can achieve very high optical resolution, which has reached 1200 × 2400dpi or above.
　　
CIS: CIS uses a touch-point image photosensitive element (photosensitive sensor) for photosensitive. From 1 to 2mm locations on the scanning platform, A line of light from a-closely arranged red, blue, and green LEDs is mixed to produce a white light source, it replaces the complex structure of CCD array, lens, fluorescent tube or cold cathode ray tube in CCD scanner, and changes CCD scanner into an integrated device and an Integrated Device of CIS scanner (optical, mechanical, electrical. The CIS product works like a fax machine. It does not have a lens component. The CIS photosensitive device spans the width of the scanning width and is as close as possible to the original. CIS uses light emitting diode as the light source and diode photosensitive element. The structure is simple and compact, so the volume can be very small. The thickness of cis products is usually less than half that of CCD products. However, because the CIS device does not have the lens imaging part, the depth of field is very small and it can only scan a plane object. CIS devices are semiconductor devices that can achieve lower costs after large-scale production. However, the CIS technology is still in development, and its optical resolution is generally only 300x600 dpi. Compared with CCD, the CCD scanning technology uses optical imaging devices to ensure that the color and brightness of the scanned image are very uniform. In addition, the high-brightness light source can achieve a very high color resolution. The CIS technology uses a large area photosensitive device, which is still difficult to ensure uniformity of scanning at present. Moreover, due to the use of diode light-emitting devices with low brightness, therefore, the color resolution of CIS is not as good as that of CCD.
　　
Ii. Classification of scanner Interfaces
　　
Scanners are classified into EPP, USB, and SCSI by interface type. They have the following features:
　　
1. EPP: its biggest feature is convenience. In addition, the speed of the enhanced EPP port is very close to that of USB and SCSI, which makes it more convenient. At the same time, EPP ports have low requirements on computers and can be used by more than 486 of all models. Therefore, if your computer is an old motherboard, it is a good choice to select the EPP interface scanner.
　　
2. USB: It features fast and easy to install. It can be plugged in with live connections. However, it has high requirements on the quality of the motherboard. USB must be supported first. In addition, tests show that if the motherboard is insufficient to provide power to the USB device, it may cause a crash during scanning. With the increasing popularity of USB applications, USB interface scanners are the development trend.
　　
3. SCSI: It features fast scanning and stable scanning, which consumes less system resources. The disadvantage is that the cost is high and installation is troublesome. In addition to high-end professional scanners, it is used less and less.
　　
Iii. main technical parameters of the scanner
　　
Resolution: The scanner resolution is the optical resolution. It refers to the number of points divided into 1 inch. For example, 1 inch DPI means that it scans 300 optical points on. The scanner also has a highest resolution, which mainly refers to the software interpolation in the optical resolution, that is, obtained through software computation.
　　
Color bits: In the scanner's technical parameters, the color bits are measured in bits. Currently, there are usually 36 and 48-bit scanners in the world. The power of 2 is the number of digits. Then 36 digits are millions of colors and 48 digits are billions of colors. The more colors (color digits), the better. But generally 36 bits are enough.
　　
ASPI: Short for Advanced SCSI Programming Interface. A programming language or protocol developed by Adaptec for communication between SCSI peripheral devices (such as scanners) and SCSI adapter cards.
　　
Automatic paper reader (ADF: Auto Document Feeder): This is an additional part of the scanner and is mainly used to assist in text scanning. You can perform a continuous scan of up to 50 pages of text pages. This accessory is usually used with optical character recognition software (OCR) instead of image editing programs like Adobe Photoshop.
　　
Bit: the smallest unit of storage in a computer. The bitwise value is 0 or 1. The more digits, the more complex the image information is. Example: Unit (Single-bit)
The Unit image uses only one data bit to record each pixel-white or black.
　　
8-bit grayscale (8-bit grayscale): displays a grayscale level of 256 (256 to the power of 2), which is used to more accurately display normal black and white photos. The gray scale of level 256 is sufficient to present a gray level that is more than the level that can be identified by the naked eye.
　　
24-bit color: A 24-bit color image consists of three 8-bit color channels. The combination of red, green, and blue channels can produce a combination of 16.77 million colors. The 24-digit color is also called full color.
　　
36-bit color: A 36-bit color image consists of three 12-bit color channels. After the red, green, and blue channels are combined, a combination of 68.7 billion colors can be generated, that is, more colors (compared with the 16.77 million colors produced by 24-bit scanners ). Because the 36-bit scanner can show more detailed color layers, the extra image information obtained by scanning can show more vivid colors and more realistic images.
　　
Brightness: a balance between the Brightness and Brightness of an image. Brightness is different from contrast. contrast is the difference between the brightest and the most dark tones in the image. Brightness determines the intensity of light and shade; contrast determines the number of light and shade layers.
　　
Color calibration: it ensures that the Color of an image can be accurately reconstructed. Complete color calibration is typically divided into two steps: calibration input devices, such as scanners; and calibration output devices, such as printers or screens. After accurate calibration of the input and output devices, the scanner can accurately capture the color, and the screen or printer can faithfully display the color.
　　
Charge-coupled device (CCD): represents the charge-coupled device, which is a long photosensitive component, the scanning process is used to convert the light waves reflected from the image into digital signals.
　　
Color channel: the red, green, and blue components that generate a color image.
　　
Color Image: a type of image that contains the most complex image information (compared with the unit image and grayscale image ). To capture color images, the scanner uses a color model based on RGB to process color data.
　　
Contrast: the relationship between the light and shade areas in an image. Comparison refers to the range of differences between the brightest and least dark tones in an image. a larger range of differences means a larger comparison, and a smaller range means a smaller comparison; brightness refers to the balance between light and shade in an image. The Contrast determines the number of light and shade layers; the brightness determines the intensity of light and shade. Low-contrast images look gray and dull.
　　
Dynamic color correction (DCR): represents dynamic color rendition (Dynamic color correction), is a unique color correction technology of quanyou computer (microtek. DCR ensures that the color of the scanned image is as close as possible to that of the original image.
　　
Descreen: a feature in the scanwizard Scan Driver to remove the online flowers and outlets that will appear when scanning printed documents.
　　　　
DPI: the number of dots per inch (the number of points per inch), used to measure a unit of resolution. The larger the DPI value, the higher the resolution.
　　
Dynamic Range: the ability of the scanner to determine the level of color from white to black. A scanner with a good concentration range can accurately present the color levels of the original, making the image clearer and more detailed. The maximum density of a scanner is determined by the number of digits. For example, a 36-digit scanner has a higher concentration value than a 24-digit scanner.
　　
Exposure: the intensity of light in an image. The exposure of an image can be changed by increasing or decreasing the photosensitive time.
　　
File format: format for storing graphical files. There are many available file formats, each of which has its own advantages and disadvantages. The most common file formats include TIFF, PICT, EPS, and PCX. TIFF is the most widely used file format.
　　
Filters: a tool for making special effects on images. Filters in Scan software include blur/Blur enhancement, sharpness/Sharpness enhancement/USM sharpness processing, relief effect and edge emphasizing effect.
　　
Grayscale image (Grayscale): a type of image that contains not only black and white, but also authentic Grayscale colors. Each pixel in a grayscale image contains multiple pieces of data to record and display more levels of light and shade. Four digits can generate level 16 gray scale, and eight digits can generate level 256 gray scale similar to photos.
　　
Halftone: a type of unit image. It is an illusion of an approximate gray-scale image produced by a black dot with different density levels. The pictures we see in the newspaper belong to this half-tone image. These images usually look rough.
　　
Highlight: the brightest area in the image.
　　
Histogram: displays the distribution statistics of light and shade pixels in an image. The proportion of the color order distribution chart is biased to the left, indicating that the image is darker, and the proportion is biased to the right, indicating that the image is brighter.
　　
Hue: A feature used to distinguish between different colors (that is, to distinguish between red, green, or blue ). Different from saturation, saturation indicates the intensity of the color (red or green ).
　　
Image editing software: software used to compile images, such as Adobe Photoshop.
　　
Image enhancement tools: a tool used in scanning software to adjust color and Image quality. These tools include BCE (brightness, contrast, and exposure adjustment), grading adjustment tools, tone adjustment tools, curve tools, and filters.
　　
Image type: the method in which you want to scan and process images. ScanWizard can choose to process half-tone images, black and white images, gray-scale images, or color images.
　　
Imagesetter: An output device used to output high-resolution images or files to photo paper or film.
　　
Interpolation resolution (Interpolated resolution): improves resolution through software, which is also called software-enhanced resolution. For example, if the optical resolution of your scanner is 300 dpi, you can increase the image to 600 dpi by using the software interpolation algorithm. Interpolation resolution is less than the detailed data obtained by optical resolution. It is useful for some specific work, such as scanning black and white images or enlarging a smaller source.
　　
Line Art: a type of unit image. It has only two colors, such as a pencil or a pen sketch. Some images of a single color can also be regarded as black and white images, such as mechanical blueprints or illustrations.
　　
Number of lines per inch (LPI): It indicates lines per inch (number of lines per inch), which is the unit of resolution used for printing. The lpi is different from dpi, dpi measures the resolution of an electronic image.
　　
Midtones: it refers to the area where the image is located in the bright and dark parts, which is about 50% gray-scale.
　　
Moire: This is an unexpected pattern during color printing. It is caused by incorrect screen angle when the half-tone image is printed. Usually, when you scan a half-tone image or scan an image directly from a magazine, the image will appear online (the scanned source is not a photo or negative image ).
　　
Optical Character Recognition (OCR): Optical Character Recognition (Optical Character Recognition), which scans an image and converts it to a text format.
　　
Optical resolution: the actual resolution of the scanner is also a key factor that determines the number of visual details in an image. Optical Resolution is one type of resolution, and the other is interpolation resolution.
　　
Pixel: The unit used by a computer to represent digital image data. For example, an image is simply represented by thousands or even millions of pixels in a grid arrangement.
　　
Printing methods: the printing method you selected should be adjusted based on the image you scanned. For example, a low-resolution black/white printer can print text and black/white images, but not grayscale images. For Grayscale Images, high-resolution printers should be used, such as printers capable of printing to 600 dpi to 1200 dpi. For color image printing, you can select a color inkjet printer, a sublimation printer or a printing press.
　　
Resolution: the granularity of the image, represented by DPI. The larger the DPI value, the larger the scan resolution and the image file obtained. There are two types of resolutions: Optical Resolution and interpolation resolution.
　　
Red, green, and blue (RGB): A color model in which different colors are composed of three primary colors: Red, green, and blue.
　　
Saturation: The color intensity, or the color intensity of a specific color. For example, a clear red apple image looks "Brighter" when the color is saturated 」.
　　
Scaling: scales up or down the image processing program in scanwizard so that the image does not need to be zoomed in or out after it is transmitted to the image editing program. The scaling ratio is inversely proportional to the resolution. For a scanner of the same type, the smaller the Resolution, the larger the image size. when the resolution is set to the highest, the image size can only be reduced.
　　
Scan material: the type of the source used for scanning. The types of scanned manuscripts can be divided into three types: reflected drafts, such as photos or printed documents; main slides, such as slides; negative films, such as negatives used for normal photography.
　　
Scanner: a scanner is a device for capturing images and converting them into digital formats that computers can display, edit, store, and output. Scanners are widely used, such as combining image and photo scanning into files; inputting printed text scanning into text processing software to avoid re-typing; enter Fax file scanning into database software or text processing software for storage, and add images to multimedia.
　　
SCSI: a small computer system interface (Small Computer System Interface) is a format of computer hardware interface.
　　
SCSI serial (SCSI chain): A serial connection circuit connecting SCSI devices in the system. A scsi serial can contain scanners, optical drives, external hard disks, and tape drives. Each SCSI device on the connection should have a different scsi id number. Otherwise, hardware conflicts may occur.
　　
Shadows: The most dark area in an image.
　　
Single-bit image: a unit image is the simplest image. Each pixel is recorded in only one position. Unit images are classified into two different types: black and white images (also known as line art) and half-tone images.
　　
Text scanning: a common application of scanners that removes the hassle of re-typing input. After scanning the text, the scanner enters the text into the Text Processing Software by processing the optical text recognition software.
　　
Terminator: A special resistance package or block that can be used to tell the computer where the SCSI serial end is and ensure the overall circuit signal stability. The electrical noise generated by numerous cables and equipment can be eliminated by the filter of terminal resistors.
　　
Mask (TMA): represents the transparent media adapter, which is a subsidiary of the scanner and is used to scan the transmitted draft, slide, or negative film. TMA has a special light source device to prevent the original article from being scrapped due to exposure to the glare for too long.
　　
Twain: A software industry standard that enables direct data transfer between software applications and hardware scanning devices. Scanwizard for Windows is a twain-compliant driver, which means it can be driven by Twain compatible applications such as Adobe Photoshop. In practice, this means that the scan results are automatically sent to the Photoshop program after scanning through scanwizard.
　　
Zoom: This is the ability to zoom in the image in the preview window.