General scanner specifications
• optical resolution (Opticalresolution) of the scanner, characterizing the density with which the scanning device selects information in a given area of the original; is determined by the size of the elementary sensor on charge-coupled devices (CCDs) and is measured in pixels per inch (ppi - pixels per inch) or points per inch (dpi - dots per inch) . In the device description, the range of possible optical resolution values is sometimes indicated, meaning that not all CCD sensors are used when scanning with a resolution lower than the maximum resolution. The maximum resolution (Maximal resolution) of the scanner is given taking into account the interpolation capabilities of the device, allowing additional points, colors or gradations of gray color between the actually scanned points to be calculated from the values of neighboring points. If you insert all the resulting pixel values into the scanned image file, the resolution of the scanner is doubled, i.e. instead of hardware 400 dpi will be equal to software 800 dpi;
• Scanning Area, which determines the maximum size of the original that can be scanned by the device;
• Optical or Dynamic Range, which characterizes the scanner's ability to reproduce smooth tones and expresses the difference between the lightest and darkest tones that can be captured with the scanner;
• Bit Bit Representation, or Color Depth, which specifies the maximum number (2 N) of colors or grayscales that are can perceive the scanner;
• The Scanning Method for describing color scanner models defines a one- or three-way way to read information about the brightness of the original image in the three primary colors of the RGB system;
• Scanning speed, which is usually understood as the number of pages of black and white originals scanned per minute with the maximum optical resolution;
• Scanning Technology, determined by the type and parameters of the light sensor used (CCD or PMT);
• The type and color of the light source (Light Source), which determine the various possible options for scanning color originals. For example, if a non-white light source is installed in the scanner, applying color filters to remove unwanted spots or shades of certain colors will not give the desired result;
• Supported computer platforms, which characterize the compatibility of the scanner with various computer systems and all peripherals and software applications used in them;
• Additional options for the scanner, which include the ability to process transparent originals, automatic feed of sheets, facsimile transmission of scanned images, etc.
• interface (Interface), by which you should understand the options for the hardware connection of the device to the computer, given in the description of the scanner.