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Documentation/IM - An Imaging Tool/IM: im_process_glo.h Source File

IM: im_process_glo.h Source File

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im_process_glo.h

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/** \file
 * \brief Image Processing - Global Operations
 *
 * See Copyright Notice in im_lib.h
 * $Id: im_process_glo.h,v 1.1 2005/04/02 22:07:00 scuri Exp $
 */

#ifndef __IM_PROCESS_GLO_H
#define __IM_PROCESS_GLO_H

#include "im_image.h"

#if defined(__cplusplus)
extern "C" {
#endif



/** \defgroup transform Domain Transform Operations
 * \par
 * FFT, Wavelts, Hough, Distance.
 * \par
 * FFTW Copyright Matteo Frigo, Steven G. Johnson and the MIT. \n
 * http://www.fftw.org                                         \n
 * See fftw.h or fftw3.h
 * \par
 * Must link with "im_fftw.lib" for FFTW version 2.1.5, and "im_fftw3.lib" for version 3.0.1. \n
 * Both libraries are available because version 3 was not that fast from version 2, 
 * and its file size is 3x bigger than version 2. But version 3 was not compiled using hardware 
 * otimizations.
 * \par
 * The FFTW lib has a GPL license. The license of the "im_fftw.lib" library is automatically the GPL.
 * So you cannot use it for commercial applications without contacting the authors. 
 * \par
 * See \ref im_process_glo.h
 * \ingroup process */

/** Forward FFT. \n
 * The result has its lowest frequency at the center of the image. \n
 * This is an unnormalized fft. \n
 * Images must be of the same size. Destiny image must be of type complex.
 * \ingroup transform */
void imProcessFFT(const imImage* src_image, imImage* dst_image);

/** Inverse FFT. \n
 * The image has its lowest frequency restored to the origin before the transform. \n
 * The result is normalized by (width*height). \n
 * Images must be of the same size and both must be of type complex.
 * \ingroup transform */
void imProcessIFFT(const imImage* src_image, imImage* dst_image);

/** Raw in-place FFT (forward or inverse). \n
 * The lowest frequency can be centered after forward, or
 * can be restored to the origin before inverse. \n
 * The result can be normalized after the transform by sqrt(w*h) [1] or by (w*h) [2], 
 * or left unnormalized [0]. \n
 * Images must be of the same size and both must be of type complex.
 * \ingroup transform */
void imProcessFFTraw(imImage* src_image, int inverse, int center, int normalize);

/** Auxiliary function for the raw FFT. \n 
 * This is the function used internally to change the lowest frequency position in the image. \n
 * If the image size has even dimensions the flag "center2origin" is useless. But if it is odd, 
 * you must specify if its from center to origin (usually used before inverse) or
 * from origin to center (usually used after forward). \n
 * Notice that this function is used for images in the the frequency domain. \n
 * Image type must be complex.
 * \ingroup transform */
void imProcessSwapQuadrants(imImage* src_image, int center2origin);

/** Hough Lines Transform. \n
 * It will detect white lines in a black background. So the source image must be a IM_BINARY image 
 * with the white lines of interest enhanced. The better the threshold with the white lines the better 
 * the line detection. \n
 * The destiny image must have IM_GRAY, IM_INT, width=180, height=2*rmax+1, where rmax is the image diagonal/2. \n
 * The houfh transform defines  "cos(theta) * X  + sin(theta) * Y = rho" and the parameters are in the interval: \n
 * theta = "0 .. 179", rho = "-height/2 .. height/2" .\n
 * Returns zero if the counter aborted. \n
 * Inspired from ideas in XITE, Copyright 1991, Blab, UiO \n
 * http://www.ifi.uio.no/~blab/Software/Xite/
 * \ingroup transform */
int imProcessHoughLines(const imImage* src_image, imImage* dst_image);

/** Draw detected hough lines. \n
 * The source image must be IM_GRAY and IM_BYTE. The destiny image can be a clone of the source image or 
 * it can be the source image for in place processing. \n
 * The hough points image is a hough transform image that was thresholded to a IM_BINARY image, 
 * usually using a Local Max threshold operation. Again the better the threshold the better the results. \n
 * The destiny image will be set to IM_MAP, and the detected lines will be drawn using a red color. \n
 * Returns the number of detected lines.
 * \ingroup transform */
int imProcessHoughLinesDraw(const imImage* src_image, const imImage* hough_points, imImage* dst_image);

/** Calculates the Cross Correlation in the frequency domain. \n 
 * CrossCorr(a,b) = IFFT(Conj(FFT(a))*FFT(b)) \n
 * Images must be of the same size and only destiny image must be of type complex.
 * \ingroup transform */
void imProcessCrossCorrelation(const imImage* src_image1, const imImage* src_image2, imImage* dst_image);

/** Calculates the Auto Correlation in the frequency domain. \n 
 * Uses the cross correlation.
 * Images must be of the same size and only destiny image must be of type complex.
 * \ingroup transform */
void imProcessAutoCorrelation(const imImage* src_image, imImage* dst_image);
/** Calculates the Distance Transform of a binary image 
 * using an aproximation of the euclidian distance.\n
 * Each white pixel in the binary image is
 * assigned a value equal to its distance from the nearest
 * black pixel. \n
 * Uses a two-pass algorithm incrementally calculating the distance. \n
 * Source image must be IM_BINARY, destiny must be IM_FLOAT.
 * \ingroup transform */
void imProcessDistanceTransform(const imImage* src_image, imImage* dst_image);

/** Marks all the regional maximum of the distance transform. \n
 * source is IMGRAY/IM_FLOAT destiny in IM_BINARY. \n
 * We consider maximum all connected pixel values that have smaller pixel values around it.
 * \ingroup transform */
void imProcessRegionalMaximum(const imImage* src_image, imImage* dst_image);


#if defined(__cplusplus)
}
#endif

#endif

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