Greyscale colour space

By Martin McBride, 2021-04-28
Tags: colour greyscale
Categories: computer science colour


Any RGB colour that has equal amounts of red, green and blue, will display as a shade of grey, for example:

  • rgb(0%, 0%, 0%) is black.
  • rgb(30%, 30%, 30%) is dark grey.
  • rgb(100%, 100%, 100%) is white.

In the greyscale colours space, the colour is specified by a single value. The colour is displayed as if the red, green and blue values were all equal. You can think of greyscale as a subset of RGB that includes only the pure grey colours.

The greyscale colour space can only show shades of grey. It is useful for images that don't include any colour, for example:

  • Text only documents.
  • Charts and diagrams that don't use colour.
  • Scans of black and white photographic images.

This image

A greyscale image only stores 1 value per pixel (the grey level), whereas an RGB image store 3 values per pixel.

See also

If you found this article useful, you might be interested in the book NumPy Recipes or other books by the same author.

Join the PythonInformer Newsletter

Sign up using this form to receive an email when new content is added:

Popular tags

2d arrays abstract data type alignment and angle animation arc array arrays bar chart bar style behavioural pattern bezier curve built-in function callable object chain circle classes clipping close closure cmyk colour combinations comparison operator comprehension context context manager conversion count creational pattern data science data types decorator design pattern device space dictionary drawing duck typing efficiency ellipse else encryption enumerate fill filter font font style for loop formula function function composition function plot functools game development generativepy tutorial generator geometry gif global variable gradient greyscale higher order function hsl html image image processing imagesurface immutable object in operator index inner function input installing iter iterable iterator itertools join l system lambda function latex len lerp line line plot line style linear gradient linspace list list comprehension logical operator lru_cache magic method mandelbrot mandelbrot set map marker style matplotlib monad mutability named parameter numeric python numpy object open operator optimisation optional parameter or pandas partial application path pattern permutations pie chart pil pillow polygon pong positional parameter print product programming paradigms programming techniques pure function python standard library radial gradient range recipes rectangle recursion reduce regular polygon repeat rgb rotation roundrect scaling scatter plot scipy sector segment sequence setup shape singleton slice slicing sound spirograph sprite square str stream string stroke structural pattern subpath symmetric encryption template tex text text metrics tinkerbell fractal transform translation transparency triangle truthy value tuple turtle unpacking user space vectorisation webserver website while loop zip zip_longest