jburkardt

IMAGE_EDGE\ Edge Detection in Images {#image_edge-edge-detection-in-images align=”center”} ========================

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IMAGE_EDGE is a C++ 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.

Licensing: {#licensing align=”center”}

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

Languages: {#languages align=”center”}

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: {#related-data-and-programs align=”center”}

EDGE, a C++ 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 C++ library which seeks the connected “nonzero” or “nonblack” components of an image or integer vector, array or 3D block.

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

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

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

Reference: {#reference align=”center”}

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: {#source-code align=”center”}

• image_edge.cp, the source code.
• image_edge.hpp, the include file.

Examples and Tests: {#examples-and-tests align=”center”}

• image_edge_prb.cpp, a sample calling program.
• image_edge_prb_output.txt, the output file.
• coins.ascii.pgm, an ASCII PGM file containing a grayscale image of coins.
• coins.png, a PNG version of the image.
• coin_edges.ascii.pbm, an ASCII PBM file containing a bitmap image of coins.
• coin_edges.png, a PNG version of the image.

List of Routines: {#list-of-routines align=”center”}

• I4_HUGE returns a “huge” I4.
• I4MAT_HISTOGRAM computes a histogram of the elements of an I4MAT.
• I4MAT_MAX returns the maximum of an I4MAT.
• NEWS demonstrates the NEWS stencil for edge detection.
• PBMA_WRITE writes the header and data for an ASCII PBM file.
• PBMA_WRITE_DATA writes the data for an ASCII PBM file.
• PBMA_WRITE_HEADER writes the header of an ASCII PBM file.
• PGMA_READ_DATA reads the data in an ASCII PGM file.
• PGMA_READ_HEADER reads the header of an ASCII PGM file.
• TIMESTAMP prints the current YMDHMS date as a time stamp.

You can go up one level to the C++ source codes.

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Last modified on 26 December 2010.