ellipse.c File Reference

2D plane model of an ellipse. More...

#include "libtpcrec.h"

Go to the source code of this file.

Functions
void	ellipseInit (ELLIPSE *ell)
void	ellipseEmpty (ELLIPSE *ell)
void	ellipseInfo (ELLIPSE *ell)
int	ellipseAllocate (ELLIPSE *ell, int imgDim)
int	ellipseSetFromParams (ELLIPSE *ell, int imgDim, float *semis, float *cent, float incli, float val)
int	ellipseReadEllipse (FILE *fp, ELLIPSE *ell)
int	ellipseSaveEllipse (ELLIPSE *ell, FILE *fp)
float	ellipseGetMajor (ELLIPSE *ell)
float	ellipseGetMinor (ELLIPSE *ell)
float	ellipseGetCenterX (ELLIPSE *ell)
float	ellipseGetCenterY (ELLIPSE *ell)
float	ellipseGetInclination (ELLIPSE *ell)
int	ellipseGetImgSize (ELLIPSE *ell)
int	ellipseGetValue (ELLIPSE *ell)
int **	ellipseGetArray (ELLIPSE *ell)
int	ellipseIsInside (ELLIPSE *ell, int row, int col)

Variables
int	ELLIPSE_TEST
	Drive in test mode if not 0.
int	ELLIPSE_VERBOSE
	Drive in verbose mode if not 0.

Detailed Description

2D plane model of an ellipse.

Author

Jarkko Johansson

Date

2004-04-20

Definition in file ellipse.c.

Function Documentation

ellipseAllocate()

int ellipseAllocate	(	ELLIPSE *	ell,
		int	imgDim )

Allocates memory for ELLIPSE data. Normally used only in SET-functions.

Precondition

ell is initialized && imgDim is positive

Postcondition

memory is allocated for ELLIPSE structure.

Parameters

ell	pointer to ellipse for which the allocation is done.
imgDim	size of the image plane on which the ellipse is to be done.

Returns

0 if ok.

Definition at line 94 of file ellipse.c.

{
  int i;
  if(ELLIPSE_VERBOSE) printf("ELLIPSE:ellipseAllocate(*ell,%i) \n",imgDim);
  
  /*check the arguments*/
  if(ell->status==ELLIPSE_STATUS_UNINITIALIZED) return(1);
  if(imgDim<1 || imgDim>4096) return(2);
  
  //allocate memory
  ell->ellipseptr=(int**)calloc(imgDim,sizeof(int*));
  for(i=0;i<imgDim;i++){
    ell->ellipseptr[i]=(int*)calloc(imgDim,sizeof(int));
  }
  return(0);
}

Referenced by ellipseSetFromParams().

ellipseEmpty()

void ellipseEmpty

(

ELLIPSE *

ell

)

Frees the memory allocated for ellipse. All data is cleared.

Postcondition

ellipse is emptied.

Parameters

ell	pointer to ellipse to be emptied.

Definition at line 47 of file ellipse.c.

{
 if(ELLIPSE_VERBOSE) printf("ELLIPSE: ellipseEmpty(). \n");
 
  //if ell is already empty
  if(ell->status<ELLIPSE_STATUS_OCCUPIED) return;
 
  //free the memory occupied by ellipse array
  free(ell->ellipseptr);
 
  //Init the information again
  ell->semiaxis[0]=ell->semiaxis[1]=0.;
  ell->center[0]=ell->center[1]=0.;
  ell->inclination=0.;
  ell->imageDim=0;
  ell->value=0;
  /*Init the ellipse array*/
  ell->ellipseptr=(int**)NULL;
 
  ell->status=ELLIPSE_STATUS_INITIALIZED;
}

Referenced by ellipseReadEllipse().

ellipseGetArray()

int ** ellipseGetArray

(

ELLIPSE *

ell

)

Returns the ellipse array of the given ellipse.

Ellipse array contains n x n items, single item is one if it is inside the ellipse and zero otherwise. Coordinates on a two dimensional plane are numbered from upper left corner.

Parameters

ell	pointer to ellipse.

Returns

the ellipse array of the given ellipse.

Definition at line 339 of file ellipse.c.

{
  if(ELLIPSE_VERBOSE) printf("ELLIPSE:ellipseGetArray(). \n");
  if(ell->status==ELLIPSE_STATUS_UNINITIALIZED) return((int**)-1);
  return(ell->ellipseptr);
}

ellipseGetCenterX()

float ellipseGetCenterX

(

ELLIPSE *

ell

)

Returns the center x-coordinate of the ellipse.

Parameters

ell	pointer to ellipse.

Returns

the center x-coordinate of the given ellipse, some negative value if ERROR.

Definition at line 277 of file ellipse.c.

{
  if(ELLIPSE_VERBOSE) printf("ELLIPSE:ellipseGetCenterX(). \n");
  if(ell->status==ELLIPSE_STATUS_UNINITIALIZED) return(-1);
  return(ell->center[0]);
}

ellipseGetCenterY()

float ellipseGetCenterY

(

ELLIPSE *

ell

)

Returns the center y-coordinate of the ellipse.

Parameters

ell	pointer to ellipse.

Returns

the center y-coordinate of the given ellipse, some negative value if ERROR.

Definition at line 289 of file ellipse.c.

{
  if(ELLIPSE_VERBOSE) printf("ELLIPSE:ellipseGetCenterY(). \n");
  if(ell->status==ELLIPSE_STATUS_UNINITIALIZED) return(-1);
  return(ell->center[1]);
}

ellipseGetImgSize()

int ellipseGetImgSize

(

ELLIPSE *

ell

)

Returns the size of the image plane on which the ellipse is drawn.

Parameters

ell	pointer to ellipse.

Returns

the size of the image plane of the given ellipse, some negative value if ERROR.

Definition at line 312 of file ellipse.c.

{
  if(ELLIPSE_VERBOSE) printf("ELLIPSE:ellipseGetImgSize(). \n");
  if(ell->status==ELLIPSE_STATUS_UNINITIALIZED) return(-1);
  return(ell->imageDim);
}

ellipseGetInclination()

float ellipseGetInclination

(

ELLIPSE *

ell

)

Returns the inclination of the ellipse.

Parameters

ell	pointer to ellipse.

Returns

the inclination of the given ellipse, some negative value if ERROR.

Definition at line 300 of file ellipse.c.

{
  if(ELLIPSE_VERBOSE) printf("ELLIPSE:ellipseGetInclination(). \n");
  if(ell->status==ELLIPSE_STATUS_UNINITIALIZED) return(-1);
  return(ell->inclination);
}

ellipseGetMajor()

float ellipseGetMajor

(

ELLIPSE *

ell

)

Returns the major semiaxe of the ellipse.

Parameters

ell	pointer to ellipse.

Returns

the major semiaxe of the given ellipse, some negative value if ERROR.

Definition at line 254 of file ellipse.c.

{
  if(ELLIPSE_VERBOSE) printf("ELLIPSE:ellipseGetMajor(). \n");
  if(ell->status==ELLIPSE_STATUS_UNINITIALIZED) return(-1);
  return(ell->semiaxis[0]);
}

Referenced by radonSetBases(), and radonSetBasesEA().

ellipseGetMinor()

float ellipseGetMinor

(

ELLIPSE *

ell

)

Returns the minor semiaxe of the ellipse.

Parameters

ell	pointer to ellipse.

Returns

the minor semiaxe of the given ellipse, some negative value if ERROR.

Definition at line 265 of file ellipse.c.

{
  if(ELLIPSE_VERBOSE) printf("ELLIPSE:ellipseGetMinor(). \n");
  if(ell->status==ELLIPSE_STATUS_UNINITIALIZED) return(-1);
  return(ell->semiaxis[1]);
}

Referenced by radonSetBases(), and radonSetBasesEA().

ellipseGetValue()

int ellipseGetValue

(

ELLIPSE *

ell

)

Returns the value of the pixels inside the ellipse.

Parameters

ell	pointer to ellipse.

Returns

the value of the pixels inside the ellipse.

Definition at line 323 of file ellipse.c.

{
  if(ELLIPSE_VERBOSE) printf("ELLIPSE:ellipseGetValue(). \n");
  if(ell->status==ELLIPSE_STATUS_UNINITIALIZED) return(-1);
  return(ell->value);
}

ellipseInfo()

void ellipseInfo

(

ELLIPSE *

ell

)

Prints the information of the ellipse to the screen.

Parameters

ell	pointer to ellipse to be printed.

Definition at line 73 of file ellipse.c.

{
  printf("ellipseInfo()\n");
  if(ell->status==ELLIPSE_STATUS_UNINITIALIZED){
    printf("Ellipse data not initialized.\n"); return;
  }
  printf("Semiaxis: (%.5f,%.5f)\n",ell->semiaxis[0], ell->semiaxis[1]);
  printf("Center: (%.2f,%.2f)\n",ell->center[0],ell->center[1]);
  printf("Inclination (degrees): %f\n",ell->inclination);
  printf("Image dimension: %i\n",ell->imageDim);
  printf("Value: %f\n",ell->value);
}

ellipseInit()

void ellipseInit

(

ELLIPSE *

ell

)

Initializes ELLIPSE datatype for use. To be used before any use of ELLIPSE type variables.

Postcondition

ellipse is initialized.

Parameters

ell	pointer to ellipse to be initialized.

Definition at line 23 of file ellipse.c.

{
  if(ELLIPSE_VERBOSE) printf("ELLIPSE: ellipseInit(). \n");
 
  /*Init the information on ellipse.*/
  //buffer ell to contain zero
  memset(ell, 0, sizeof(ELLIPSE)); 
  ell->status=ELLIPSE_STATUS_INITIALIZED;
  ell->semiaxis[0]=ell->semiaxis[1]=0.;
  ell->center[0]=ell->center[1]=0.;
  ell->inclination=0.;
  ell->imageDim=0;
  ell->value=0;
 
  /*Init the ellipse array*/
  ell->ellipseptr=(int**)NULL;
}

ellipseIsInside()

int ellipseIsInside	(	ELLIPSE *	ell,
		int	row,
		int	col )

Tests whether the given pixel is inside the given ellipse or not.

Returns

one if the given pixel is inside the given ellipse zero otherwise, some negative value if ERROR.

Parameters

ell	ellipse on which the testing is to be done.

Precondition

ell is initialized && 0<=row<=imgDim-1 && 0<=col<=imgDim-1.

Parameters

row	row coordinate of a pixel.
col	column coordinate of a pixel.

Definition at line 352 of file ellipse.c.

  {
  //no checking on parameters to accelerate use inside a loop
  return(ell->ellipseptr[row][col]);
}

Referenced by radonSetBases(), radonSetBasesEA(), and radonSetLUT().

ellipseReadEllipse()

int ellipseReadEllipse	(	FILE *	fp,
		ELLIPSE *	ell )

Reads one ellipse from the given file to the given ELLIPSE structure.

A coordinate file contains the parameters of the ellipses in one line in the following order: Coordinate 1: v the additive intensity value of the ellipse Coordinate 2: a the length of the horizontal semi-axis of the ellipse Coordinate 3: b the length of the vertical semi-axis of the ellipse Coordinate 4: x the x-coordinate of the center of the ellipse Coordinate 5: y the y-coordinate of the center of the ellipse Coordinate 6: p the angle (in degrees) between the horizontal semi-axis of the ellipse and the x-axis of the image
Coordinate 7: d the image dimension

Postcondition

An ellipse is read from the file fname.

Returns

0 if ok 1 if there were no more ellipses.

Parameters

fp	A pointer to open file containing ellipse(s) in correct format.
ell	pointer to ELLIPSE structure where the read ellipse is to be set.

Precondition

ell is initialized.

Definition at line 198 of file ellipse.c.

  {
  float v, incli, semiaxis[2], center[2], imgDim;
  int ret=0;
 
  if(ELLIPSE_VERBOSE) printf("ellipseReadEllipse() \n");
 
  if(fread(&v,sizeof(float),1,fp)==0) {fclose(fp); return(2);}
  if(fread(&semiaxis[0],sizeof(float),1,fp)==0) {fclose(fp); return(2);}
  if(fread(&semiaxis[1],sizeof(float),1,fp)==0) {fclose(fp); return(2);}
  if(fread(&center[0],sizeof(float),1,fp)==0) {fclose(fp); return(2);}
  if(fread(&center[1],sizeof(float),1,fp)==0) {fclose(fp); return(2);}
  if(fread(&incli,sizeof(float),1,fp)==0) {fclose(fp); return(2);}
  if(fread(&imgDim,sizeof(float),1,fp)==0) {fclose(fp); return(2);}
 
  if(feof(fp)) return 1;
 
  //create the ellipse
  ret=ellipseSetFromParams(ell, imgDim, semiaxis, center, incli,v);
  if(ret){ ellipseEmpty(ell); return ret;}
  return 0;
}

ellipseSaveEllipse()

int ellipseSaveEllipse	(	ELLIPSE *	ell,
		FILE *	fp )

Adds the given ellipse to the file.

Postcondition

ellipse is saved in the file called fname.

Returns

0 if OK.

Parameters

ell	Pointer to the ellipse to be saved.
fp	Open file for saving.

Definition at line 230 of file ellipse.c.

  {
  if(ELLIPSE_VERBOSE) printf("ellipseSaveEllipse()\n");
 
  // Put ellipse in the file.
  fwrite(&(ell->value),sizeof(float),1,fp);
  fwrite(&(ell->semiaxis[0]),sizeof(float),1,fp);
  fwrite(&(ell->semiaxis[1]),sizeof(float),1,fp);
  fwrite(&(ell->center[0]),sizeof(float),1,fp);
  fwrite(&(ell->center[1]),sizeof(float),1,fp);
  fwrite(&(ell->inclination),sizeof(float),1,fp);
  fwrite(&(ell->imageDim),sizeof(float),1,fp);
 
  return(0);
}

ellipseSetFromParams()

int ellipseSetFromParams	(	ELLIPSE *	ell,
		int	imgDim,
		float *	semis,
		float *	cent,
		float	incli,
		float	val )

Sets the ellipse according to given coordinates and image dimension.

Note

The origin is in the middle.

Postcondition

ellipse is set.

Returns

0 if ok.

Parameters

ell	pointer to ellipse for which the setting is to be done.

Precondition

ell is initialized.

Parameters

imgDim

size of the image plane.

Precondition

imgDim is positive.

Parameters

semis

major and minor semiaxis of the ellipse.

Precondition

semis[i] are positive.

Parameters

cent	center of the ellipse.

Precondition

-imgDim/2<=cent[i]<=imgDim/2.

Parameters

incli	inclination of the ellipse.
val	value inside the ellipse.

Definition at line 119 of file ellipse.c.

  {
  float    d, x, y, inclination;
  int      row, col;
 
  /*check the arguments*/
  if(ell->status==ELLIPSE_STATUS_UNINITIALIZED) return(1);
  if(imgDim<1 || imgDim>4096) return(2);
  if(0>semis[0] || 0>semis[1]) return(3);
  if(-(float)imgDim/2.>cent[0] || (float)imgDim/2.<cent[0]) return(4);
  if(-(float)imgDim/2.>cent[1] || (float)imgDim/2.<cent[1]) return(5);
 
  //allocate memory for ellipse
  ellipseAllocate(ell,imgDim);
 
  //set the information on ellipse
  ell->semiaxis[0]=semis[0];
  ell->semiaxis[1]=semis[1];
  ell->center[0]=cent[0];
  ell->center[1]=cent[1];
  ell->inclination=incli;
  ell->imageDim=imgDim;
  ell->value=val;
 
  //set inclination ratio for setting inclination approximately
  inclination= -(float)(incli/90.);
 
  //set ellipse array according to given arguments
  for(row=0; row<imgDim; row++) {
   for(col=0; col<imgDim; col++) {
     // the y-coordinate of row in coordinates where origin is set in the middle
     y=(float)imgDim*0.5 - (float)row - cent[1]; 
     /* the x-coordinate of column in coordinates where origin is set in 
        the middle and inclination is added */
     x=(float)col - (float)imgDim*0.5 - (cent[0] + inclination*y); 
     d=(x*x)/(semis[0]*semis[0]) + (y*y)/(semis[1]*semis[1]); 
       //if this pixel is inside the ellipse
       if(d<1.0) { 
         //put 1 in place (row,col)
   ell->ellipseptr[row][col]=1;
       }
   }//END OF COL-LOOP 
  }//END OF ROW-LOOP
  return(0);
}

Referenced by ellipseReadEllipse().

Variable Documentation

ELLIPSE_TEST

int ELLIPSE_TEST

Drive in test mode if not 0.

Definition at line 8 of file ellipse.c.

ELLIPSE_VERBOSE

int ELLIPSE_VERBOSE

Drive in verbose mode if not 0.

Definition at line 9 of file ellipse.c.

Referenced by ellipseAllocate(), ellipseEmpty(), ellipseGetArray(), ellipseGetCenterX(), ellipseGetCenterY(), ellipseGetImgSize(), ellipseGetInclination(), ellipseGetMajor(), ellipseGetMinor(), ellipseGetValue(), ellipseInit(), ellipseReadEllipse(), and ellipseSaveEllipse().