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nbis: add one more step of false minutia removal

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Remove minutiae that are located on scan perimeter
This commit is contained in:
Vasily Khoruzhick 2015-03-15 16:13:32 +03:00
parent f1fdd71613
commit 59fe0fb699
3 changed files with 167 additions and 0 deletions
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5
libfprint/nbis/include/lfs.h
View file

@ -236,6 +236,8 @@ typedef struct lfsparms{
int pores_steps_bwd;
double pores_min_dist2;
double pores_max_ratio;
int remove_perimeter_pts;
int min_pp_distance;
/* Ridge Counting Controls */
int max_nbrs;
@ -585,6 +587,9 @@ typedef struct lfsparms{
/* contour points to be considered a pore. */
#define PORES_MAX_RATIO 2.25
/* Points which are closer than this distance to scan perimeter will be removed */
#define PERIMETER_PTS_DISTANCE 10
/***** RIDGE COUNTING CONSTANTS *****/

4
libfprint/nbis/mindtct/globals.c
View file

@ -129,6 +129,8 @@ LFSPARMS g_lfsparms = {
PORES_STEPS_BWD,
PORES_MIN_DIST2,
PORES_MAX_RATIO,
FALSE, /* not removing perimeter points by default */
PERIMETER_PTS_DISTANCE,
/* Ridge Counting Controls */
MAX_NBRS,
@ -213,6 +215,8 @@ LFSPARMS g_lfsparms_V2 = {
PORES_STEPS_BWD,
PORES_MIN_DIST2,
PORES_MAX_RATIO,
FALSE, /* not removing perimeter points by default */
PERIMETER_PTS_DISTANCE,
/* Ridge Counting Controls */
MAX_NBRS,

158
libfprint/nbis/mindtct/remove.c
View file

@ -1350,6 +1350,159 @@ static int remove_overlaps(MINUTIAE *minutiae,
return(0);
}
static void mark_minutiae_in_range(MINUTIAE *minutiae, int *to_remove, int x, int y,
const LFSPARMS *lfsparms)
{
int i, dist;
for (i = 0; i < minutiae->num; i++) {
if (to_remove[i])
continue;
dist = (int)sqrt((x - minutiae->list[i]->x) * (x - minutiae->list[i]->x) +
(y - minutiae->list[i]->y) * (y - minutiae->list[i]->y));
if (dist < lfsparms->min_pp_distance) {
to_remove[i] = 1;
}
}
}
/*************************************************************************
**************************************************************************
#cat: remove_perimeter_pts - Takes a list of true and false minutiae and
#cat: attempts to detect and remove those false minutiae that
#cat: belong to image edge
Input:
minutiae - list of true and false minutiae
bdata - binary image data (0==while & 1==black)
iw - width (in pixels) of image
ih - height (in pixels) of image
lfsparms - parameters and thresholds for controlling LFS
Output:
minutiae - list of pruned minutiae
Return Code:
Zero - successful completion
Negative - system error
**************************************************************************/
static int remove_perimeter_pts(MINUTIAE *minutiae,
unsigned char *bdata, const int iw, const int ih,
const LFSPARMS *lfsparms)
{
int i, j, ret, *to_remove;
int *left, *left_up, *left_down;
int *right, *right_up, *right_down;
int removed = 0;
int left_min, right_max;
if (!lfsparms->remove_perimeter_pts)
return(0);
to_remove = calloc(minutiae->num, sizeof(int));
left = calloc(ih, sizeof(int));
left_up = calloc(ih, sizeof(int));
left_down = calloc(ih, sizeof(int));
right = calloc(ih, sizeof(int));
right_up = calloc(ih, sizeof(int));
right_down = calloc(ih, sizeof(int));
/* Pass downwards */
left_min = iw - 1;
right_max = 0;
for (i = 0; i < ih; i++) {
for (j = 0; j < left_min; j++) {
if ((bdata[i * iw + j] != 0)) {
left_min = j;
break;
}
}
if (left_min == (iw - 1))
left_down[i] = -1;
else
left_down[i] = left_min;
for (j = iw - 1; j >= right_max; j--) {
if ((bdata[i * iw + j] != 0)) {
right_max = j;
break;
}
}
if (right_max == 0)
right_down[i] = -1;
else
right_down[i] = right_max;
}
/* Pass upwards */
left_min = iw - 1;
right_max = 0;
for (i = ih - 1; i >= 0; i--) {
for (j = 0; j < left_min; j++) {
if ((bdata[i * iw + j] != 0)) {
left_min = j;
break;
}
}
if (left_min == (iw - 1))
left_up[i] = -1;
else
left_up[i] = left_min;
for (j = iw - 1; j >= right_max; j--) {
if ((bdata[i * iw + j] != 0)) {
right_max = j;
break;
}
}
if (right_max == 0)
right_up[i] = -1;
else
right_up[i] = right_max;
}
/* Merge */
left_min = left_down[ih - 1];
right_max = right_down[ih - 1];
for (i = 0; i < ih; i++) {
if (left_down[i] != left_min)
left[i] = left_down[i];
else
left[i] = left_up[i];
if (right_down[i] != right_max)
right[i] = right_down[i];
else
right[i] = right_up[i];
}
free(left_up);
free(left_down);
free(right_up);
free(right_down);
/* Mark minitiae close to the edge */
for (i = 0; i < ih; i++) {
if (left[i] != -1)
mark_minutiae_in_range(minutiae, to_remove, left[i], i, lfsparms);
if (right[i] != -1)
mark_minutiae_in_range(minutiae, to_remove, right[i], i, lfsparms);
}
free(left);
free(right);
for (i = minutiae->num - 1; i >= 0; i--) {
/* If the current minutia index is flagged for removal ... */
if (to_remove[i]){
removed ++;
/* Remove the minutia from the minutiae list. */
if((ret = remove_minutia(i, minutiae))){
free(to_remove);
return(ret);
}
}
}
free(to_remove);
return (0);
}
/*************************************************************************
**************************************************************************
#cat: remove_pores_V2 - Attempts to detect and remove minutia points located on
@ -2104,6 +2257,11 @@ int remove_false_minutia_V2(MINUTIAE *minutiae,
return(ret);
}
/* 11. Remove minutiae on image edge */
if((ret = remove_perimeter_pts(minutiae, bdata, iw, ih, lfsparms))) {
return (ret);
}
return(0);
}