IMAGE_COMPONENTS
Connected Components of an Image or Matrix

IMAGE_COMPONENTS is a FORTRAN77 library which seeks to count and label the connected nonzero/nonblack components in an image or integer vector, matrix or 3D block.

Licensing:

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

Languages:

IMAGE_COMPONENTS 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:

IMAGE_DENOISE, a FORTRAN77 library which applies simple filtering techniques to remove noise from an image.

IMAGE_EDGE, a FORTRAN77 library which demonstrates a simple procedure for edge detection in images.

REGION, a FORTRAN90 library which reads 3D MRI voxel data, and groups the voxels into connected regions;

Reference:

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.

Source Code:

• components.f, the source code.
• components.sh, BASH commands to compile the source code.

Examples and Tests:

• components_prb.f, a sample calling program.
• components_prb.sh, BASH commands to compile and run the sample program.
• components_prb_output.txt, the output file.
• indices.txt, a file of 3D indices needed for the test of I4BLOCK_COMPONENTS.

List of Routines:

• FILE_COLUMN_COUNT counts the number of columns in the first line of a file.
• FILE_ROW_COUNT counts the number of row records in a file.
• GET_UNIT returns a free FORTRAN unit number.
• I4BLOCK_COMPONENTS assigns contiguous nonzero pixels to a common component.
• I4MAT_COMPONENTS assigns contiguous nonzero pixels to a common component.
• I4MAT_DATA_READ reads data from an I4MAT file.
• I4MAT_HEADER_READ reads the header from an I4MAT.
• I4VEC_COMPONENTS assigns contiguous nonzero pixels to a common component.
• S_TO_I4 reads an I4 from a string.
• S_TO_I4VEC reads an I4VEC from a string.
• S_WORD_COUNT counts the number of "words" in a string.
• TIMESTAMP prints the current YMDHMS date as a time stamp.

You can go up one level to the FORTRAN77 source codes.