Edge Detection in Images

IMAGE_EDGE is a FORTRAN90 library which demonstrates the detection of edges in an image.

NEWS is a particularly simple edge detection scheme, which compares the North, East, West, and South neighbors of a pixel to determine if the pixel lies along an edge.

There are many sophisticated edge detection algorithms, and MATLAB has many of them built into its image processing toolbox. The purpose of these examples is simply to demonstrate how a simple version of such edge detection schemes works.


The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.


IMAGE_EDGE is available in a C version and a C++ version and a FORTRAN77 version and a FORTRAN90 version and a MATLAB version.

Related Data and Programs:

EDGE, a FORTRAN90 library which defines some test functions in 1D, 2D and 3D for the detection of edges or discontinuities. It uses GNUPLOT to display the jumps in curves and surfaces.

IMAGE_COMPONENTS, a FORTRAN90 library which seeks the connected "nonzero" or "nonblack" components of an image or integer vector, array or 3D block.

IMAGE_DENOISE, a FORTRAN90 library which applies simple filtering techniques to remove noise from an image.

PBMA_IO, a FORTRAN90 library which handles the ASCII Portable Bit Map (PBM) format.

PGMA_IO, a FORTRAN90 library which handles the ASCII Portable Gray Map (PGM) format.


  1. Jonas Gomes, Luiz Velho,
    Image Processing for Computer Graphics,
    Springer, 1997,
    ISBN: 0387948546,
    LC: T385.G65.
  2. William Pratt,
    Digital Image Processing,
    Second Edition,
    Wiley, 1991,
    ISBN13: 978-0471857662,
    LC: TA1632.P7.
  3. Barry Wilkinson, Michael Allen,
    Parallel Programming: Techniques and Applications using Networked Workstations and Parallel Computers,
    Pearson/Prentice Hall, 2005,
    ISBN: 0-13-140563-2,
    LC: QA76.642.W54.

Source Code:

Examples and Tests:

COINS is a picture of coins.

PEPPER is a picture of peppers.

List of Routines:

You can go up one level to the FORTRAN90 source codes.

Last modified on 26 December 2010.