image_threshold

image_threshold, an Octave code which creates a black and white version of a grayscale image by specifying a single threshold value; pixels below this value become black, and above this value they are white.

Usage:

function bw = image_threshold ( gray, a )

• gray is an m by n uint8 (short integers, 0 to 255) array containing the grayscale image data; MATLAB's imread() command can be used to create such a dataset from a graphics image file.
• a is a value between 0 and 255 which is used for thresholding.
• bw is an m by n uint8 array containing the gray scale version of the thresholded image. All values in this array are 0 or 255.

Licensing:

The information on this web page is distributed under the MIT license.

Languages:

image_threshold is available in a MATLAB version and an Octave version.

Related Data and Programs:

image_threshold_test

Reference:

• Jonas Gomes, Luiz Velho,
  Image Processing for Computer Graphics,
  Springer, 1997,
  ISBN: 0387948546,
  LC: T385.G65.
• William Pratt,
  Digital Image Processing,
  Second Edition,
  Wiley, 1991,
  ISBN13: 978-0471857662,
  LC: TA1632.P7.

Source Code:

• image_threshold.m, sets pixels less than or equal to A to black, and pixels greater than A to white.
• image_threshold2.m, sets pixels less than A to black, and pixels greater than B to white, leaving intermediate pixels unchanged.
• image_threshold3.m, sets pixels less than A or greater than B to white, leaving intermediate pixels unchanged.