- Bit depth
- The number of tonal values recorded per color channel in a digital file. 8-bit files record 256 values per channel; 16-bit files record 65,536. 16-bit (48-bit total) files will appear identical to 8 bit but when subject to heavy editing the additional data in the 16 version bit will allow the resulting file to look much more natural and keep smooth transitions. 32 bit files support HDR imaging in photography but there is no current printing technology that can input 32 bit data.
- Channel
- An individual grayscale set of data representing an individual color. Red, Green or Blue in RGB mode or Cyan, Magenta, Yellow, and Black in CMYK mode.
- Color gamut
- A range of colors that can be reproduced by a given equipment or potentially represented in a file.
- Color management
- The use of ICC profiles to ensure that colors are interpreted consistently across different devices — scanner, monitor, printer — throughout an imaging workflow.
- Color space
- The range of colors a digital file can represent. Common color spaces include sRGB (narrower, for screen use), Adobe RGB (wider, for print), and ProPhoto RGB (widest, for high-gamut output).
- Contactless scanning
- Scanning in which no pressure is applied to the surface of the artwork. The sensor and light source pass over the work without physical contact, reducing handling risk as opposed to lying face down on a glass bed.
- DC Synchrolight
- A patented Metis scanning technology that uses eight independently controlled light sources, dynamically adjusted in angle and intensity during capture, to render surface texture and material properties with accuracy unavailable from fixed-light scanning systems
- Depth of field
- The range of surface heights that remain in sharp focus during a scan. A scanner with a large, user-selectable depth of field can capture dimensionally complex surfaces — textiles, impasto, collage — without blurring.
- DPI
- A commonly mis-used term. DPI refers to dots per square inch such as a printer might output 1200 dots of ink in an inch to produce detailed smooth results. DPI can also mean how many dots per inch frequency on a screen for silk screening and other printmaking processes. DPI is commonly confused with PPI: Pixels Per Inch which is the correct term for describing resolution.
- Dynamic range
- The range of tonal values a scanner can capture simultaneously, from the deepest shadow to the brightest highlight. Higher dynamic range preserves detail in both extremes and is critical for high-contrast artwork.
- Giclée
- A high-quality inkjet printing process using archival pigment inks on fine art papers or canvas. Giclée printing is the standard method for fine art print reproduction and edition production.
- ICC profile
- A standardized file that describes the color characteristics of a device — scanner, monitor, or printer — allowing color-managed software to translate colors accurately between different parts of a workflow.
- Impasto
- A painting technique in which paint is applied thickly, creating raised texture and dimensional surface relief. Capturing impasto faithfully requires directional lighting during scanning.
- Interpolated resolution
- A software process which generates additional pixels between the pixels that are actually captured by the sensor, producing a larger file without adding real detail from the original. Interpolated resolution figures — often very large numbers used in scanner marketing — describe computed pixels, not optically captured ones. For fine art and archival purposes, native optical resolution is the only figure that indicates true capture quality. See also: Native Optical Resolution.
- JPEG
- A standard imaging format known for its small file size and versatility. However its method of compression (saving size) results in a loss of information. This is known as a lossy format and is not recommended as a final or archival format. Jpeg compression can result in images looking blocky and pixelated.
- Large-format scanning
- Scanning of artwork whose dimensions exceed the capacity of a standard flatbed scanner, typically requiring specialized equipment with large scan beds or multi-pass stitching capability.
- Lossless / Lossy
- Various file formats can be compressed to save space and upload/download time. However the methods are very different. Lossless formats such as TIFF (LZW) or PNG do not lose any information. However formats such as Jpeg are lossy where there is a trade off of file size and image quality. Final scan or image files that are archived should always be lossless.
- MDC / SuperScan
- A proprietary Metis file format that records all lighting configurations from a single scan simultaneously, allowing the visual appearance of the scan to be adjusted after capture without rescanning.
- Optical resolution
- The true resolving capability of a scanner's imaging sensor and optics — the number of distinct pixels the hardware can capture per inch of the original artwork without computational assistance. Native optical resolution is a fixed physical property of the instrument and the only resolution figure that represents real captured detail. It should be distinguished from interpolated resolution, which uses software to generate additional pixels from the captured data. When comparing scanning services or equipment, always ask for the native optical resolution. See also: Interpolated Resolution.
- Photometric stereo
- A scanning technique that derives accurate 3D surface data from 2D image captures taken under multiple lighting angles. Used to generate depth maps and glossiness maps from artwork scans.
- Pixel
- The simplest or smallest element of a digital image. Usually square.
- Pixelation
- AKA jaggies. The visual effect caused by images being rendered at too low a resolution. It can easily be defined as a stair-stepped effect giving a diagonal or curved line or image a rough appearance.
- PPI (pixels per inch)
- The measure of scanning resolution — how many pixels are captured per inch of original artwork. Higher PPI produces larger files with more detail and greater potential print scale.
- Raster image
- An image built, pixel by pixel, in a series of rows, one line after another.
- RGB
- A color model using red, green, and blue; the additive primary colors. All cameras and scanners as well as video display systems use RGB data to create images.
- Scan Merge / stitching
- The process of combining multiple scan passes into a single seamless file, used when an artwork exceeds the single-pass bed size of the scanner. Professional stitching systems align passes automatically with sub-pixel accuracy.
- TIFF (Tagged Image File Format)
- A lossless digital image file format standard for professional fine art scanning delivery. Unlike JPEG, TIFF preserves all image data without compression artifacts.
