[DEV] extract edtaa3 from ewol
This commit is contained in:
commit
d30f86280e
524
edtaa3/edtaa3func.c
Normal file
524
edtaa3/edtaa3func.c
Normal file
@ -0,0 +1,524 @@
|
||||
/*
|
||||
* Copyright 2009 Stefan Gustavson (stefan.gustavson@gmail.com)
|
||||
* All rights reserved.
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions are met:
|
||||
*
|
||||
* 1. Redistributions of source code must retain the above copyright notice,
|
||||
* this list of conditions and the following disclaimer.
|
||||
*
|
||||
* 2. Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in the
|
||||
* documentation and/or other materials provided with the distribution.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY STEFAN GUSTAVSON ''AS IS'' AND ANY EXPRESS OR
|
||||
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
|
||||
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
|
||||
* EVENT SHALL STEFAN GUSTAVSON OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
|
||||
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
|
||||
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
||||
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
|
||||
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
||||
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
||||
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
||||
*
|
||||
* The views and conclusions contained in the software and documentation are
|
||||
* those of the authors and should not be interpreted as representing official
|
||||
* policies, either expressed or implied, of Stefan Gustavson.
|
||||
*
|
||||
*
|
||||
* edtaa3()
|
||||
*
|
||||
* Sweep-and-update Euclidean distance transform of an
|
||||
* image. Positive pixels are treated as object pixels,
|
||||
* zero or negative pixels are treated as background.
|
||||
* An attempt is made to treat antialiased edges correctly.
|
||||
* The input image must have pixels in the range [0,1],
|
||||
* and the antialiased image should be a box-filter
|
||||
* sampling of the ideal, crisp edge.
|
||||
* If the antialias region is more than 1 pixel wide,
|
||||
* the result from this transform will be inaccurate.
|
||||
*
|
||||
* By Stefan Gustavson (stefan.gustavson@gmail.com).
|
||||
*
|
||||
* Originally written in 1994, based on a verbal
|
||||
* description of the SSED8 algorithm published in the
|
||||
* PhD dissertation of Ingemar Ragnemalm. This is his
|
||||
* algorithm, I only implemented it in C.
|
||||
*
|
||||
* Updated in 2004 to treat border pixels correctly,
|
||||
* and cleaned up the code to improve readability.
|
||||
*
|
||||
* Updated in 2009 to handle anti-aliased edges.
|
||||
*
|
||||
* Updated in 2011 to avoid a corner case infinite loop.
|
||||
*
|
||||
*/
|
||||
#include <math.h>
|
||||
|
||||
|
||||
/*
|
||||
* Compute the local gradient at edge pixels using convolution filters.
|
||||
* The gradient is computed only at edge pixels. At other places in the
|
||||
* image, it is never used, and it's mostly zero anyway.
|
||||
*/
|
||||
void computegradient(double *img, int w, int h, double *gx, double *gy)
|
||||
{
|
||||
int i,j,k;
|
||||
double glength;
|
||||
#define SQRT2 1.4142136
|
||||
for(i = 1; i < h-1; i++) { // Avoid edges where the kernels would spill over
|
||||
for(j = 1; j < w-1; j++) {
|
||||
k = i*w + j;
|
||||
if((img[k]>0.0) && (img[k]<1.0)) { // Compute gradient for edge pixels only
|
||||
gx[k] = -img[k-w-1] - SQRT2*img[k-1] - img[k+w-1] + img[k-w+1] + SQRT2*img[k+1] + img[k+w+1];
|
||||
gy[k] = -img[k-w-1] - SQRT2*img[k-w] - img[k+w-1] + img[k-w+1] + SQRT2*img[k+w] + img[k+w+1];
|
||||
glength = gx[k]*gx[k] + gy[k]*gy[k];
|
||||
if(glength > 0.0) { // Avoid division by zero
|
||||
glength = sqrt(glength);
|
||||
gx[k]=gx[k]/glength;
|
||||
gy[k]=gy[k]/glength;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
// TODO: Compute reasonable values for gx, gy also around the image edges.
|
||||
// (These are zero now, which reduces the accuracy for a 1-pixel wide region
|
||||
// around the image edge.) 2x2 kernels would be suitable for this.
|
||||
}
|
||||
|
||||
/*
|
||||
* A somewhat tricky function to approximate the distance to an edge in a
|
||||
* certain pixel, with consideration to either the local gradient (gx,gy)
|
||||
* or the direction to the pixel (dx,dy) and the pixel greyscale value a.
|
||||
* The latter alternative, using (dx,dy), is the metric used by edtaa2().
|
||||
* Using a local estimate of the edge gradient (gx,gy) yields much better
|
||||
* accuracy at and near edges, and reduces the error even at distant pixels
|
||||
* provided that the gradient direction is accurately estimated.
|
||||
*/
|
||||
double edgedf(double gx, double gy, double a) {
|
||||
double df, glength, temp, a1;
|
||||
if ((gx == 0) || (gy == 0)) { // Either A) gu or gv are zero, or B) both
|
||||
df = 0.5-a; // Linear approximation is A) correct or B) a fair guess
|
||||
} else {
|
||||
glength = sqrt(gx*gx + gy*gy);
|
||||
if(glength>0) {
|
||||
gx = gx/glength;
|
||||
gy = gy/glength;
|
||||
}
|
||||
/* Everything is symmetric wrt sign and transposition,
|
||||
* so move to first octant (gx>=0, gy>=0, gx>=gy) to
|
||||
* avoid handling all possible edge directions.
|
||||
*/
|
||||
gx = fabs(gx);
|
||||
gy = fabs(gy);
|
||||
if(gx<gy) {
|
||||
temp = gx;
|
||||
gx = gy;
|
||||
gy = temp;
|
||||
}
|
||||
a1 = 0.5*gy/gx;
|
||||
if (a < a1) { // 0 <= a < a1
|
||||
df = 0.5*(gx + gy) - sqrt(2.0*gx*gy*a);
|
||||
} else if (a < (1.0-a1)) { // a1 <= a <= 1-a1
|
||||
df = (0.5-a)*gx;
|
||||
} else { // 1-a1 < a <= 1
|
||||
df = -0.5*(gx + gy) + sqrt(2.0*gx*gy*(1.0-a));
|
||||
}
|
||||
}
|
||||
return df;
|
||||
}
|
||||
|
||||
double distaa3(double *img, double *gximg, double *gyimg, int w, int c, int xc, int yc, int xi, int yi) {
|
||||
double di, df, dx, dy, gx, gy, a;
|
||||
int closest;
|
||||
|
||||
closest = c-xc-yc*w; // Index to the edge pixel pointed to from c
|
||||
a = img[closest]; // Grayscale value at the edge pixel
|
||||
gx = gximg[closest]; // X gradient component at the edge pixel
|
||||
gy = gyimg[closest]; // Y gradient component at the edge pixel
|
||||
|
||||
if(a > 1.0) {
|
||||
a = 1.0;
|
||||
}
|
||||
if(a < 0.0) {
|
||||
a = 0.0; // Clip grayscale values outside the range [0,1]
|
||||
}
|
||||
if(a == 0.0) {
|
||||
return 1000000.0; // Not an object pixel, return "very far" ("don't know yet")
|
||||
}
|
||||
|
||||
dx = (double)xi;
|
||||
dy = (double)yi;
|
||||
di = sqrt(dx*dx + dy*dy); // Length of integer vector, like a traditional EDT
|
||||
if(di==0) { // Use local gradient only at edges
|
||||
// Estimate based on local gradient only
|
||||
df = edgedf(gx, gy, a);
|
||||
} else {
|
||||
// Estimate gradient based on direction to edge (accurate for large di)
|
||||
df = edgedf(dx, dy, a);
|
||||
}
|
||||
return di + df; // Same metric as edtaa2, except at edges (where di=0)
|
||||
}
|
||||
|
||||
// Shorthand macro: add ubiquitous parameters dist, gx, gy, img and w and call distaa3()
|
||||
#define DISTAA(c,xc,yc,xi,yi) (distaa3(img, gx, gy, w, c, xc, yc, xi, yi))
|
||||
|
||||
void edtaa3(double *img, double *gx, double *gy, int w, int h, short *distx, short *disty, double *dist)
|
||||
{
|
||||
int x, y, i, c;
|
||||
int offset_u, offset_ur, offset_r, offset_rd,
|
||||
offset_d, offset_dl, offset_l, offset_lu;
|
||||
double olddist, newdist;
|
||||
int cdistx, cdisty, newdistx, newdisty;
|
||||
int changed;
|
||||
double epsilon = 1e-3;
|
||||
|
||||
/* Initialize index offsets for the current image width */
|
||||
offset_u = -w;
|
||||
offset_ur = -w+1;
|
||||
offset_r = 1;
|
||||
offset_rd = w+1;
|
||||
offset_d = w;
|
||||
offset_dl = w-1;
|
||||
offset_l = -1;
|
||||
offset_lu = -w-1;
|
||||
|
||||
/* Initialize the distance images */
|
||||
for(i=0; i<w*h; i++) {
|
||||
distx[i] = 0; // At first, all pixels point to
|
||||
disty[i] = 0; // themselves as the closest known.
|
||||
if(img[i] <= 0.0){
|
||||
dist[i]= 1000000.0; // Big value, means "not set yet"
|
||||
} else if (img[i]<1.0) {
|
||||
dist[i] = edgedf(gx[i], gy[i], img[i]); // Gradient-assisted estimate
|
||||
} else {
|
||||
dist[i]= 0.0; // Inside the object
|
||||
}
|
||||
}
|
||||
|
||||
/* Perform the transformation */
|
||||
do {
|
||||
changed = 0;
|
||||
|
||||
/* Scan rows, except first row */
|
||||
for(y=1; y<h; y++) {
|
||||
/* move index to leftmost pixel of current row */
|
||||
i = y*w;
|
||||
/* scan right, propagate distances from above & left */
|
||||
/* Leftmost pixel is special, has no left neighbors */
|
||||
olddist = dist[i];
|
||||
if(olddist > 0) { // If non-zero distance or not set yet
|
||||
c = i + offset_u; // Index of candidate for testing
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx;
|
||||
newdisty = cdisty+1;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon) {
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
olddist=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
c = i+offset_ur;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx-1;
|
||||
newdisty = cdisty+1;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon) {
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
}
|
||||
i++;
|
||||
/* Middle pixels have all neighbors */
|
||||
for(x=1; x<w-1; x++, i++) {
|
||||
olddist = dist[i];
|
||||
if(olddist <= 0) {
|
||||
continue; // No need to update further
|
||||
}
|
||||
c = i+offset_l;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx+1;
|
||||
newdisty = cdisty;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon) {
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
olddist=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
c = i+offset_lu;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx+1;
|
||||
newdisty = cdisty+1;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon) {
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
olddist=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
c = i+offset_u;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx;
|
||||
newdisty = cdisty+1;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon) {
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
olddist=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
c = i+offset_ur;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx-1;
|
||||
newdisty = cdisty+1;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon) {
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
}
|
||||
/* Rightmost pixel of row is special, has no right neighbors */
|
||||
olddist = dist[i];
|
||||
if(olddist > 0) {// If not already zero distance
|
||||
c = i+offset_l;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx+1;
|
||||
newdisty = cdisty;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon) {
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
olddist=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
c = i+offset_lu;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx+1;
|
||||
newdisty = cdisty+1;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon) {
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
olddist=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
c = i+offset_u;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx;
|
||||
newdisty = cdisty+1;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon) {
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
}
|
||||
/* Move index to second rightmost pixel of current row. */
|
||||
/* Rightmost pixel is skipped, it has no right neighbor. */
|
||||
i = y*w + w-2;
|
||||
/* scan left, propagate distance from right */
|
||||
for(x=w-2; x>=0; x--, i--) {
|
||||
olddist = dist[i];
|
||||
if(olddist <= 0) {
|
||||
continue; // Already zero distance
|
||||
}
|
||||
c = i+offset_r;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx-1;
|
||||
newdisty = cdisty;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon) {
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
}
|
||||
}
|
||||
/* Scan rows in reverse order, except last row */
|
||||
for(y=h-2; y>=0; y--) {
|
||||
/* move index to rightmost pixel of current row */
|
||||
i = y*w + w-1;
|
||||
/* Scan left, propagate distances from below & right */
|
||||
/* Rightmost pixel is special, has no right neighbors */
|
||||
olddist = dist[i];
|
||||
if(olddist > 0) { // If not already zero distance
|
||||
c = i+offset_d;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx;
|
||||
newdisty = cdisty-1;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon) {
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
olddist=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
|
||||
c = i+offset_dl;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx+1;
|
||||
newdisty = cdisty-1;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon) {
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
}
|
||||
i--;
|
||||
/* Middle pixels have all neighbors */
|
||||
for(x=w-2; x>0; x--, i--) {
|
||||
olddist = dist[i];
|
||||
if(olddist <= 0) {
|
||||
continue; // Already zero distance
|
||||
}
|
||||
c = i+offset_r;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx-1;
|
||||
newdisty = cdisty;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon) {
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
olddist=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
c = i+offset_rd;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx-1;
|
||||
newdisty = cdisty-1;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon) {
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
olddist=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
c = i+offset_d;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx;
|
||||
newdisty = cdisty-1;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon) {
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
olddist=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
c = i+offset_dl;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx+1;
|
||||
newdisty = cdisty-1;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon) {
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
}
|
||||
/* Leftmost pixel is special, has no left neighbors */
|
||||
olddist = dist[i];
|
||||
if(olddist > 0) { // If not already zero distance
|
||||
c = i+offset_r;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx-1;
|
||||
newdisty = cdisty;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon) {
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
olddist=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
c = i+offset_rd;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx-1;
|
||||
newdisty = cdisty-1;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon) {
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
olddist=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
c = i+offset_d;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx;
|
||||
newdisty = cdisty-1;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon) {
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
}
|
||||
/* Move index to second leftmost pixel of current row. */
|
||||
/* Leftmost pixel is skipped, it has no left neighbor. */
|
||||
i = y*w + 1;
|
||||
for(x=1; x<w; x++, i++) {
|
||||
/* scan right, propagate distance from left */
|
||||
olddist = dist[i];
|
||||
if(olddist <= 0) {
|
||||
continue; // Already zero distance
|
||||
}
|
||||
c = i+offset_l;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx+1;
|
||||
newdisty = cdisty;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon) {
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
}
|
||||
}
|
||||
} while(changed); // Sweep until no more updates are made
|
||||
/* The transformation is completed. */
|
||||
}
|
100
edtaa3/edtaa3func.h
Normal file
100
edtaa3/edtaa3func.h
Normal file
@ -0,0 +1,100 @@
|
||||
/*
|
||||
* Copyright 2009 Stefan Gustavson (stefan.gustavson@gmail.com)
|
||||
* All rights reserved.
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions are met:
|
||||
*
|
||||
* 1. Redistributions of source code must retain the above copyright notice,
|
||||
* this list of conditions and the following disclaimer.
|
||||
*
|
||||
* 2. Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in the
|
||||
* documentation and/or other materials provided with the distribution.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY STEFAN GUSTAVSON ''AS IS'' AND ANY EXPRESS OR
|
||||
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
|
||||
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
|
||||
* EVENT SHALL STEFAN GUSTAVSON OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
|
||||
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
|
||||
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
||||
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
|
||||
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
||||
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
||||
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
||||
*
|
||||
* The views and conclusions contained in the software and documentation are
|
||||
* those of the authors and should not be interpreted as representing official
|
||||
* policies, either expressed or implied, of Stefan Gustavson.
|
||||
*
|
||||
*
|
||||
* edtaa3()
|
||||
*
|
||||
* Sweep-and-update Euclidean distance transform of an
|
||||
* image. Positive pixels are treated as object pixels,
|
||||
* zero or negative pixels are treated as background.
|
||||
* An attempt is made to treat antialiased edges correctly.
|
||||
* The input image must have pixels in the range [0,1],
|
||||
* and the antialiased image should be a box-filter
|
||||
* sampling of the ideal, crisp edge.
|
||||
* If the antialias region is more than 1 pixel wide,
|
||||
* the result from this transform will be inaccurate.
|
||||
*
|
||||
* By Stefan Gustavson (stefan.gustavson@gmail.com).
|
||||
*
|
||||
* Originally written in 1994, based on a verbal
|
||||
* description of the SSED8 algorithm published in the
|
||||
* PhD dissertation of Ingemar Ragnemalm. This is his
|
||||
* algorithm, I only implemented it in C.
|
||||
*
|
||||
* Updated in 2004 to treat border pixels correctly,
|
||||
* and cleaned up the code to improve readability.
|
||||
*
|
||||
* Updated in 2009 to handle anti-aliased edges.
|
||||
*
|
||||
* Updated in 2011 to avoid a corner case infinite loop.
|
||||
*
|
||||
*/
|
||||
#ifndef __EDTAA3FUNC_H__
|
||||
#define __EDTAA3FUNC_H__
|
||||
|
||||
#ifdef __cplusplus
|
||||
extern "C" {
|
||||
#endif
|
||||
|
||||
|
||||
#include <math.h>
|
||||
|
||||
|
||||
/*
|
||||
* Compute the local gradient at edge pixels using convolution filters.
|
||||
* The gradient is computed only at edge pixels. At other places in the
|
||||
* image, it is never used, and it's mostly zero anyway.
|
||||
*/
|
||||
void computegradient(double *img, int w, int h, double *gx, double *gy);
|
||||
|
||||
/*
|
||||
* A somewhat tricky function to approximate the distance to an edge in a
|
||||
* certain pixel, with consideration to either the local gradient (gx,gy)
|
||||
* or the direction to the pixel (dx,dy) and the pixel greyscale value a.
|
||||
* The latter alternative, using (dx,dy), is the metric used by edtaa2().
|
||||
* Using a local estimate of the edge gradient (gx,gy) yields much better
|
||||
* accuracy at and near edges, and reduces the error even at distant pixels
|
||||
* provided that the gradient direction is accurately estimated.
|
||||
*/
|
||||
double edgedf(double gx, double gy, double a);
|
||||
|
||||
|
||||
double distaa3(double *img, double *gximg, double *gyimg, int w, int c, int xc, int yc, int xi, int yi);
|
||||
|
||||
// Shorthand macro: add ubiquitous parameters dist, gx, gy, img and w and call distaa3()
|
||||
#define DISTAA(c,xc,yc,xi,yi) (distaa3(img, gx, gy, w, c, xc, yc, xi, yi))
|
||||
|
||||
void edtaa3(double *img, double *gx, double *gy, int w, int h, short *distx, short *disty, double *dist);
|
||||
|
||||
|
||||
#ifdef __cplusplus
|
||||
}
|
||||
#endif
|
||||
|
||||
#endif // __EDTAA3FUNC_H__
|
24
license.txt
Normal file
24
license.txt
Normal file
@ -0,0 +1,24 @@
|
||||
Copyright 2009 Stefan Gustavson (stefan.gustavson@gmail.com)
|
||||
All rights reserved.
|
||||
|
||||
Redistribution and use in source and binary forms, with or without
|
||||
modification, are permitted provided that the following conditions are met:
|
||||
|
||||
1. Redistributions of source code must retain the above copyright notice,
|
||||
this list of conditions and the following disclaimer.
|
||||
|
||||
2. Redistributions in binary form must reproduce the above copyright
|
||||
notice, this list of conditions and the following disclaimer in the
|
||||
documentation and/or other materials provided with the distribution.
|
||||
|
||||
THIS SOFTWARE IS PROVIDED BY STEFAN GUSTAVSON ''AS IS'' AND ANY EXPRESS OR
|
||||
IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
|
||||
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
|
||||
EVENT SHALL STEFAN GUSTAVSON OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
|
||||
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
|
||||
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
||||
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
|
||||
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
||||
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
||||
THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
||||
|
25
lutin_edtaa3.py
Normal file
25
lutin_edtaa3.py
Normal file
@ -0,0 +1,25 @@
|
||||
#!/usr/bin/python
|
||||
import lutinModule as module
|
||||
import lutinTools as tools
|
||||
import lutinTools
|
||||
|
||||
def get_desc():
|
||||
return "edtaa3 library (create distance field from image)"
|
||||
|
||||
def create(target):
|
||||
# module name is 'edn' and type binary.
|
||||
myModule = module.Module(__file__, 'edtaa3', 'LIBRARY')
|
||||
|
||||
# add the file to compile:
|
||||
myModule.add_src_file([
|
||||
'edtaa3/edtaa3func.c'
|
||||
])
|
||||
|
||||
myModule.compile_version_CC(1999)
|
||||
|
||||
myModule.add_export_path(tools.get_current_path(__file__))
|
||||
|
||||
# add the currrent module at the
|
||||
return myModule
|
||||
|
||||
|
Loading…
Reference in New Issue
Block a user