utils.h

This distribution contains source code for a simple object tracking program using particle filterin

/** @file
    This file contains prototypes for miscellaneous utility functions.
    
    @author Rob Hess
    @version 1.0.0-20050829
*/

#ifndef UTILS_H
#define UTILS_H

#include "defs.h"

/**************************** Function Prototypes ****************************/



/**
   A function to get a pixel value from a 32-bit floating-point image.
   
   @param img an image
   @param r row
   @param c column
   @return Returns the value of the pixel at (\a r, \a c) in \a img
*/
inline float pixval32f( IplImage* img, int r, int c );


/**
   A function to set a pixel value in a 32-bit floating-point image.
   
   @param img an image
   @param r row
   @param c column
   @param val pixel value
*/
inline void setpix32f( IplImage* img, int r, int c, float val );


/**
   A function to print an error message then exit the program.
   
   @param format an error message format string (as with \c printf(3)).
*/
extern void fatal_error( char* format, ... );


/**
   A function to replace a file's extension.  

   @param file the name of a file
   @param new_extn a new file extension for \a file.  \a new_extn
     should not include a dot (i.e. \c "jpg", not \c ".jpg") unless the new
     file extension should contain two dots.
   @return Returns \a file with its extension replaced.  If
     \a file does not have an extension, this function simply
     adds one.
*/
extern char* replace_extension( const char* file, const char* new_extn );


/**
   A function to prepend a path to a filename.

   @param path a path
   @param file a file name
   @return Returns a full path name with \a path prepended to
     \a file.
*/
extern char* prepend_path( const char* path, const char* file );


/**
   A function that removes the path from a filename.

   @param pathname a (full) path name
   @return Returns \a pathname with everything up to and including
     the last \c '/' removed.  If \a pathname does not contain a \c '/',
     it is returned without modification.
*/
extern char* remove_path( const char* pathname );


/**
   A function to determine whether a file is an image file.  The determination
   is made based solely on the file's extension.  Files with the following
   extensions are considered image files: .\c png, .\c jpg, .\c jpeg, .\c pbm,
   .\c pgm, .\c ppm, .\c bmp, .\c tif, .\c tiff.

   @param file a file name
   @return Returns TRUE if \a file has one of the extensions listed
     above, and FALSE otherwise.
*/
extern int is_image_file( char* file );


/**
   A function to draw an x on an image.

   @param img an image
   @param pt the center point of the x
   @param r the x's radius
   @param w the x's line weight
   @param color the color of the x
*/
extern void draw_x( IplImage* img, CvPoint pt, int r, int w, CvScalar color );


/**
   A function to denote progress in the console with a spinning pinwheel.
   Every time this function is called, the state of the pinwheel is
   incremented.  The pinwheel has four states that loop indefinitely: | / - \.
   
   @param done if FALSE, this function simply increments the state of the
     pinwheel; if TRUE, prints "done" rather than incrementing the pinwheel.
*/
extern void progress( int done );


/**
   A function to erase a certain number of characters from a stream.
   
   @param stream the stream from which to erase characters
   @param n the number of characters to erase
*/
extern void erase_from_stream( FILE* stream, int n );


/**
   A function that doubles the size of an array with error checking

   @param array pointer to an array whose size is to be doubled
   @param n number of elements allocated for \a array
   @param size size of elements in \a array

   @return Returns the new number of elements allocated for \a array.  If no
     memory was available, returns 0 and sets \c errno to ENOMEM.
*/
extern int array_double( void** array, int n, int size );

#endif