Digital printing

Digital printing usually involves mapping the colours in a digital file (JPEG, PNG, SVG) to the CMYK colour model and printing the data onto paper using cyan, magenta, yellow and black inks.

  • Digital printers typically use highly reflective white paper overlaid with cyan, magenta, yellow and black pigments in the form of ink or toner.
  • Printing has a smaller gamut than display devices (screens, monitors, projectors) which rely on light emission, rather than reflection
  • Display devices produce comparatively brighter, more intense colours than printers because the amplitude of each wavelength is larger on an emissive source.
  • Digital printers produce dull and less intense colours than display devices because the amplitude of each wavelength is smaller when light is reflected off paper through inks or pigments.
  • A display device, such as a computer screen, starts in a black state and is illuminated with red, green and blue light to produce colour.
  • Printers typically use a highly reflective white paper and add CMYK (cyan, magenta, yellow and black) ink or toner to produce colour.
  • CMYK pigments are the standard for colour printing because they have a larger gamut than RGB pigments.
  • Highlights are produced by reducing the amount of coloured ink and printing without black to allow the maximum amount of light possible to shine through and reflect off the paper.
  • Mid tones rely on the brilliance and transparency of the pigments and the reflectivity of the paper to produce fully saturated colours.
  • Shadows are produced by adding black to both saturated or desaturated hues.

https://en.wikipedia.org/wiki/Digital_printing

Dispersion

Dispersion (or chromatic dispersion) refers to the way that light, under certain conditions, separates into its component wavelengths and the colours corresponding with each wavelength become visible to a human observer.

  • Dispersion is the result of the relationship between refractive index and wavelength.
  • Every wavelength of light is affected to a different degree by the refractive index of a medium and as a result, changes direction by a different amount eg. when passing from one medium (such as air) to another (such as glass). In the case of white light, the separate wavelengths span out with red at one end and violet at the other.
  • Another familiar example of dispersion is when white light strikes raindrops and a rainbow of colours become visible to an observer.
  • As the light first enters and then exits a droplet it separates into its component wavelengths which the observer perceives as colour.
  • Colour is not a property of electromagnetic radiation, but a feature of visual perception by an observer.

https://en.wikipedia.org/wiki/Dispersion_(optics)

Dispersion

Dispersion (or chromatic dispersion) refers to the way that light, under certain conditions, separates into its component wavelengths and the colours corresponding with each wavelength become visible to a human observer.

  • Dispersion is the result of the relationship between refractive index and wavelength.
  • Every wavelength of light is affected to a different degree by the refractive index of a medium and as a result, changes direction by a different amount eg. when passing from one medium (such as air) to another (such as glass). In the case of white light, the separate wavelengths span out with red at one end and violet at the other.
  • Another familiar example of dispersion is when white light strikes raindrops and a rainbow of colours become visible to an observer.
  • As the light first enters and then exits a droplet it separates into its component wavelengths which the observer perceives as colour.
  • Colour is not a property of electromagnetic radiation, but a feature of visual perception by an observer.

Display device

RGB display devices include computer screens, televisions, mobile phone screens, monitors and projectors.

  • A display device is an output device for presentation of information in a visual form. When the input information is in the form of a digital electrical signal, the display is called an electronic display.
  • An RGB display device adjusts the RGB colour values of each individual pixels to produce an image.
  • Fully saturated hues (colours) rely on the brilliance of each individual pixel.
  • Tints of any hue are produced by increased the value of each RGB component proportionally, which increases the amplitude of the overall output.
  • Shades are produced by decreasing the value of each RGB component proportionally so decreasing the amplitude of the overall output and thus dimming the device.

https://en.wikipedia.org/wiki/Display_device