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graphcut.c
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graphcut.c
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/* graphcut.c
2D Graphcut utility.
Copyright (c) 2007,2008,2009,2010 Matthias Kramm <kramm@quiss.org>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
#include <stdlib.h>
#include <stdio.h>
#include <assert.h>
#include <math.h>
#include <memory.h>
#include "graphcut.h"
//#define DEBUG
//#define CHECKS
//#define PREPROCESS
#ifdef DEBUG
#define DBG
#else
#define DBG if(0)
#endif
#define ACTIVE 0x10
#define IN_TREE 0x20
#define RIGHT_FLAG 1
#define UP_FLAG 2
#define LEFT_FLAG 4
#define DOWN_FLAG 8
#define TWOTREES
/* [REVERSE-DIR(2)] [IN_TREE] [ACTIVE] [UP][DOWN][LEFT][RIGHT] */
static int inv[4] = {2, 3, 0, 1};
static int bit[4] = {1, 2, 4, 8};
static int xadd[4] = {1,0,-1,0};
static int yadd[4] = {0,-1,0,1};
static char*dirname[] = {"right","up","left","down","stay"};
typedef struct _posqueue_entry {
int pos;
struct _posqueue_entry*next;
} posqueue_entry_t;
typedef struct _posqueue {
posqueue_entry_t*list;
} posqueue_t;
typedef struct _graphcut_workspace {
unsigned char*flags1;
unsigned char*flags2;
map_t*map;
int width;
int height;
int size;
int add[4];
int pos1;
int pos2;
posqueue_t*queue1;
posqueue_t*queue2;
posqueue_t*tmpqueue;
} graphcut_workspace_t;
static posqueue_t*posqueue_new()
{
posqueue_t*m = (posqueue_t*)malloc(sizeof(posqueue_t));
memset(m, 0, sizeof(posqueue_t));
return m;
}
static void posqueue_delete(posqueue_t*q)
{
free(q);
}
static inline void posqueue_addpos(posqueue_t*queue, int pos)
{
posqueue_entry_t*old = queue->list;
queue->list = malloc(sizeof(posqueue_entry_t));
queue->list->pos = pos;
queue->list->next = old;
}
static inline int posqueue_extract(posqueue_t*queue)
{
posqueue_entry_t*item = queue->list;
int pos;
if(!item)
return -1;
pos = item->pos;
queue->list = queue->list->next;
free(item);
return pos;
}
static inline int posqueue_notempty(posqueue_t*queue)
{
return (int)queue->list;
}
static void posqueue_print(posqueue_t*queue)
{
posqueue_entry_t*e = queue->list;
while(e) {
printf("%d ", e->pos);
e = e->next;
}
printf("\n");
}
static void posqueue_purge(posqueue_t*queue)
{
posqueue_entry_t*e = queue->list;
while(e) {
posqueue_entry_t*next = e->next;
e->next = 0;free(e);
e = next;
}
queue->list = 0;
}
map_t* map_new(int width, int height)
{
map_t*map = malloc(sizeof(map_t));
map->width = width;
map->height = height;
map->weight[0] = malloc(sizeof(map->weight[0][0])*width*height);
map->weight[1] = malloc(sizeof(map->weight[1][0])*width*height);
map->weight[2] = malloc(sizeof(map->weight[2][0])*width*height);
map->weight[3] = malloc(sizeof(map->weight[3][0])*width*height);
memset(map->weight[0], 0, sizeof(map->weight[0][0])*width*height);
memset(map->weight[1], 0, sizeof(map->weight[1][0])*width*height);
memset(map->weight[2], 0, sizeof(map->weight[2][0])*width*height);
memset(map->weight[3], 0, sizeof(map->weight[3][0])*width*height);
return map;
}
void map_delete(map_t*map)
{
free(map->weight[0]);map->weight[0] = 0;
free(map->weight[1]);map->weight[1] = 0;
free(map->weight[2]);map->weight[2] = 0;
free(map->weight[3]);map->weight[3] = 0;
free(map);
}
map_t* map_from_matrix(matrix_t*m)
{
map_t*map = map_new(m->width, m->height);
int x,y;
for(y=0;y<m->height;y++) {
double*prev = y?&m->data[(y-1)*m->width]:&m->data[y*m->width];
double*line = &m->data[y*m->width];
double*next= (y<m->height-1)?&m->data[(y+1)*m->width]:&m->data[y*m->width];
int prevx = 0;
int nextx = 1;
int pos = y*map->width;
for(x=0;x<m->width;x++) {
map->weight[RIGHT][pos] = (weight_t)fabs(line[x] - line[nextx]); //right
map->weight[UP ][pos] = (weight_t)fabs(prev[x] - line[x]); //up
map->weight[LEFT ][pos] = (weight_t)fabs(line[x] - line[prevx]); //left
map->weight[DOWN ][pos] = (weight_t)fabs(next[x] - line[x]); //down
pos++;
prevx = x;
if(x<m->width-2) {
nextx++;
}
}
}
inverse_map(map);
return map;
}
int coldiff(RGBA a, RGBA b)
{
int dr = a.r - b.r;
int dg = a.g - b.g;
int db = a.b - b.b;
return (int)(1+sqrt(dr*dr + dg*dg + db*db));
}
map_t* map_from_image(image_t*img)
{
map_t*map = map_new(img->width, img->height);
int x,y;
for(y=0;y<img->height;y++) {
RGBA*prev = y?&img->data[(y-1)*img->width]:&img->data[y*img->width];
RGBA*line = &img->data[y*img->width];
RGBA*next= (y<img->height-1)?&img->data[(y+1)*img->width]:&img->data[y*img->width];
int prevx = 0;
int nextx = 1;
int pos = y*map->width;
for(x=0;x<img->width;x++) {
map->weight[RIGHT][pos] = (weight_t)coldiff(line[x],line[nextx]); //right
map->weight[UP ][pos] = (weight_t)coldiff(prev[x],line[x]); //up
map->weight[LEFT ][pos] = (weight_t)coldiff(line[x],line[prevx]); //left
map->weight[DOWN ][pos] = (weight_t)coldiff(next[x],line[x]); //down
pos++;
prevx = x;
if(x<img->width-2) {
nextx++;
}
}
}
inverse_map(map);
return map;
}
static void make_map_borders(map_t*map)
{
int x,y;
for(x=0;x<map->width;x++) {
map->weight[DOWN][(map->height-1)*map->width+x] = 0;
map->weight[UP][0*map->width+x] = 0;
}
for(y=0;y<map->width;y++) {
map->weight[RIGHT][map->width-1+y*map->width] = 0;
map->weight[LEFT][y*map->width] = 0;
}
}
void inverse_map(map_t*map)
{
int t,size=map->width*map->height;
int d=0;
weight_t max = 0;
weight_t min = MAX_WEIGHT;
for(d=0;d<4;d++) {
for(t=0;t<size;t++) {
if(map->weight[d][t] < min)
min = map->weight[d][t];
if(map->weight[d][t] > max)
max = map->weight[d][t];
}
}
for(d=0;d<4;d++) {
for(t=0;t<size;t++) {
U32 v = map->weight[d][t];
//v = max-(v-min);
//v = 15 * ((v-min))/(max-min) + 1;
v = ((max-min) - (v-min));// + 1;
v = (U32)((double)v*(double)v*(double)v / 280);
map->weight[d][t] = v;
}
}
make_map_borders(map);
}
void map_save(map_t*map, char*filename)
{
FILE*fi = fopen(filename, "wb");
fprintf(fi, "width: %d\n", map->width);
fprintf(fi, "height: %d\n", map->width);
fprintf(fi, "[left]\n");
int x,y;
for(y=0;y<map->height;y++) {
for(x=0;x<map->width;x++) {
fprintf(fi, "%d ", map->weight[LEFT][y*map->width+x]);
}
fprintf(fi, "\n");
}
fprintf(fi, "[up]\n");
for(y=0;y<map->height;y++) {
for(x=0;x<map->width;x++) {
fprintf(fi, "%d ", map->weight[UP][y*map->width+x]);
}
fprintf(fi, "\n");
}
fprintf(fi, "[right]\n");
for(y=0;y<map->height;y++) {
for(x=0;x<map->width;x++) {
fprintf(fi, "%d ", map->weight[RIGHT][y*map->width+x]);
}
fprintf(fi, "\n");
}
fprintf(fi, "[down]\n");
for(y=0;y<map->height;y++) {
for(x=0;x<map->width;x++) {
fprintf(fi, "%d ", map->weight[DOWN][y*map->width+x]);
}
fprintf(fi, "\n");
}
fclose(fi);
}
static graphcut_workspace_t*graphcut_workspace_new(map_t*map, int width, int height, int pos1, int pos2)
{
graphcut_workspace_t*workspace = malloc(sizeof(graphcut_workspace_t));
workspace->width = width;
workspace->height = height;
workspace->flags1 = malloc(width*height);
memset(workspace->flags1, 0, width*height);
workspace->flags2 = malloc(width*height);
memset(workspace->flags2, 0, width*height);
workspace->size = width*height;
workspace->add[0] = 1;
workspace->add[1] = -width;
workspace->add[2] = -1;
workspace->add[3] = width;
workspace->pos1 = pos1;
workspace->pos2 = pos2;
workspace->map = map;
workspace->queue1 = posqueue_new();
workspace->queue2 = posqueue_new();
workspace->tmpqueue = posqueue_new();
return workspace;
}
static void graphcut_workspace_delete(graphcut_workspace_t*w)
{
posqueue_delete(w->queue1);w->queue1=0;
posqueue_delete(w->queue2);w->queue2=0;
if(w->flags1) free(w->flags1);w->flags1=0;
if(w->flags2) free(w->flags2);w->flags2=0;
free(w);
}
typedef struct _path {
int*pos;
unsigned char*dir;
unsigned char*firsthalf;
int length;
} path_t;
static path_t*path_new(int len)
{
path_t*p = malloc(sizeof(path_t));
p->pos = malloc(sizeof(int)*len);
p->dir = malloc(sizeof(unsigned char)*len);
p->firsthalf = malloc(sizeof(unsigned char)*len);
p->length = len;
return p;
}
static void path_delete(path_t*path)
{
free(path->pos);path->pos = 0;
free(path->dir);path->dir = 0;
free(path->firsthalf);path->firsthalf = 0;
free(path);
}
static path_t*extract_path(graphcut_workspace_t*work, unsigned char*mytree, unsigned char*othertree, int pos, int newpos, int dir)
{
int t;
int p = pos;
int len1 = 0;
/* walk up tree1 */
while(p != work->pos1) {
p += work->add[mytree[p]>>6];
len1++;
}
p = newpos;
int len2 = 0;
/* walk up tree2 */
while(p != work->pos2) {
p += work->add[othertree[p]>>6];
len2++;
}
path_t*path = path_new(len1+len2+2);
t = len1;
path->pos[t] = p = pos;
path->dir[t] = dir;
path->firsthalf[t] = 1;
while(p != work->pos1) {
assert(mytree[p]&IN_TREE);
char dir = mytree[p]>>6;
p += work->add[dir];
t--;
path->pos[t] = p;
path->dir[t] = inv[dir];
path->firsthalf[t] = 1;
}
assert(!t);
t = len1+1;
p = newpos;
while(p != work->pos2) {
assert(othertree[p]&IN_TREE);
path->pos[t] = p;
path->dir[t] = othertree[p]>>6;
path->firsthalf[t] = 0;
p += work->add[othertree[p]>>6];
t++;
}
/* terminator */
path->pos[t] = p;
path->dir[t] = 4; // last node
path->firsthalf[t] = 0;
assert(t == len1+len2+1);
return path;
}
static void map_print(graphcut_workspace_t*w)
{
int y;
map_t*map = w->map;
for(y=0;y<w->height;y++) {
int c=0;
for(c=0;c<4;c++) {
int x;
for(x=0;x<w->width;x++) {
int p = y*w->width+x;
unsigned char f = w->flags1[p]|w->flags2[p];
char cc1='-', cc2='.', cc3='.', cc4='.',cc5='.', cc6='-';
char mark=' ';
if(f) {
if(f&LEFT_FLAG) cc1='<';
if(f&RIGHT_FLAG) cc6='>';
if(f&UP_FLAG) cc2='^';
if(f&DOWN_FLAG) cc5='v';
char*cc = " atA";
char*dd = "ruld";
cc3=cc[((f>>4)&3)];
if(w->flags2[p]) {
mark = '*';
}
if(w->flags1[p] && w->flags2[p]) {
cc3 = '?';
mark = '?';
}
cc4=dd[f>>6];
}
if(c==0) printf(" %c %2d%c ", mark, map->weight[UP][p], cc2);
if(c==1) printf(" %2d%c%c%c%c%-2d", map->weight[LEFT][p], cc1, cc3, cc4, cc6, map->weight[RIGHT][p]);
if(c==2) printf(" %c%-2d ", cc5, map->weight[DOWN][p]);
if(c==3) printf(" ");
}
printf(" |\n");
}
}
}
static void path_print(path_t*path, int width)
{
int t;
for(t=0;t<path->length;t++) {
int p = path->pos[t];
printf("%d/%d(%d)", p%width, p/width, path->firsthalf[t]);
if(t<path->length-1)
printf(" -%s-> ", dirname[path->dir[t]]);
}
printf("\n");
}
static void workspace_print(graphcut_workspace_t*w)
{
printf("queue1: ");posqueue_print(w->queue1);
printf("queue2: ");posqueue_print(w->queue2);
map_print(w);
}
static void myassert(graphcut_workspace_t*w, char assertion, const char*file, int line, const char*func)
{
if(!assertion) {
printf("Assertion %s:%d (%s) failed:\n", file, line, func);
workspace_print(w);
exit(0);
}
}
#define ASSERT(w,c) {myassert(w,c,__FILE__,__LINE__,__func__);}
static path_t* expand_pos(graphcut_workspace_t*w, posqueue_t*queue, int pos, char reverse, unsigned char*mytree, unsigned char*othertree)
{
map_t*map = w->map;
int dir;
if(!(mytree[pos]&IN_TREE) || !(mytree[pos]&ACTIVE)) {
/* this node got deleted or marked inactive in the meantime. ignore it */
return 0;
}
for(dir=0;dir<4;dir++) {
int newpos = pos + w->add[dir];
if(newpos<0 || newpos>=w->size || mytree[newpos])
continue;
int weight=0;
if(!reverse) {
weight = map->weight[dir][pos];
} else {
weight = map->weight[inv[dir]][newpos];
}
if(weight) {
if(othertree[newpos]) {
posqueue_addpos(queue, pos); mytree[pos] |= ACTIVE; // re-add, this vertice might have other connections
path_t*path;
if(reverse) {
path = extract_path(w, othertree, mytree, newpos, pos, inv[dir]);
} else {
path = extract_path(w, mytree, othertree, pos, newpos, dir);
}
return path;
} else {
DBG printf("advance into direction %d to new pos %d\n", dir, newpos);
mytree[pos] |= bit[dir];
mytree[newpos] = (inv[dir]<<6)|ACTIVE|IN_TREE;
posqueue_addpos(queue, newpos);
#if 0
posqueue_addpos(queue, pos); mytree[pos] |= ACTIVE; // re-add, this vertice might have other connections
return 0;
#endif
}
}
}
/* if we couldn't expand this node anymore, it's now an inactive node */
mytree[pos] &= ~ACTIVE;
return 0;
}
static weight_t decrease_weights(map_t*map, path_t*path)
{
int t;
int min = 0;
#ifdef CHECKS
for(t=0;t<path->length-1;t++) {
assert(path->pos[t]<map->width*map->height);
int x1 = path->pos[t] % map->width;
int y1 = path->pos[t] / map->width;
int x2 = path->pos[t+1] % map->width;
int y2 = path->pos[t+1] / map->width;
assert(path->dir[t]<4);
assert(xadd[path->dir[t]] == x2-x1);
assert(yadd[path->dir[t]] == y2-y1);
}
assert(path->dir[path->length-1] == 4);
#endif
for(t=0;t<path->length-1;t++) {
int w = map->weight[path->dir[t]][path->pos[t]];
if(t == 0 || w < min)
min = w;
}
if(min<=0)
return;
for(t=0;t<path->length-1;t++) {
map->weight[path->dir[t]][path->pos[t]] -= min;
map->weight[inv[path->dir[t]]][path->pos[t+1]] += min;
}
return min;
}
static void bool_op(graphcut_workspace_t*w, unsigned char*flags, int pos, unsigned char and, unsigned char or)
{
posqueue_t*q = w->tmpqueue;
posqueue_purge(q);
posqueue_addpos(q, pos);
while(posqueue_notempty(q)) {
int p = posqueue_extract(q);
flags[p] = (flags[p]&and)|or;
int dir;
for(dir=0;dir<4;dir++) {
if(flags[p] & bit[dir]) {
posqueue_addpos(q, p+w->add[dir]);
}
}
}
}
static int reconnect(graphcut_workspace_t*w, unsigned char*flags, int pos, char reverse)
{
map_t*map = w->map;
int d;
for(d=0;d<4;d++) {
int add = w->add[d];
int newpos = pos+add;
if(newpos<0 || newpos>=w->size)
continue;
int weight;
if(!reverse) {
weight = map->weight[inv[d]][newpos];
} else {
weight = map->weight[d][pos];
}
if(weight && (flags[pos+add]&IN_TREE)) {
DBG printf("successfully reconnected node %d/%d to %d/%d\n", pos%w->width, pos/w->width, (pos+add)%w->width, (pos+add)/w->width);
flags[pos] = (flags[pos]&0x3f) | d<<6; // reverse
flags[pos + add] |= bit[inv[d]]; // forward
return 1;
}
}
return 0;
}
//#define SIMPLE
static void destroy_subtree(graphcut_workspace_t*w, unsigned char*flags, int pos, posqueue_t*posqueue, int startpos)
{
DBG printf("destroying subtree starting with %d/%d\n", pos%w->width, pos/w->width);
#ifdef SIMPLE
posqueue_purge(q);
posqueue_addpos(q, startpos);
memset(flags, 0, w->width*w->height);
return;
#else
posqueue_t*q = w->tmpqueue;
posqueue_purge(q);
posqueue_addpos(q, pos);
while(posqueue_notempty(q)) {
int p = posqueue_extract(q);
int dir;
for(dir=0;dir<4;dir++) {
int newpos = p+w->add[dir];
if(newpos<0 || newpos>w->size)
continue;
if(flags[p] & bit[dir]) {
posqueue_addpos(q, newpos);
} else if((flags[newpos]&(ACTIVE|IN_TREE)) == IN_TREE) {
// TODO: we should check the weight of that edge right now, right here.
// if it's zero, we don't need to do anything.
posqueue_addpos(posqueue, newpos);
flags[newpos]|=ACTIVE;
}
}
DBG printf("removed pos %d/%d\n", p%w->width, p/w->width);
flags[p] = 0;
}
#endif
}
static void combust_tree(graphcut_workspace_t*w, posqueue_t*q1, posqueue_t*q2, path_t*path)
{
map_t*map = w->map;
int t;
for(t=0;t<path->length-1 && path->firsthalf[t+1];t++) {
int pos = path->pos[t];
int dir = path->dir[t];
int newpos = pos+w->add[dir];
if(!map->weight[dir][pos]) {
/* disconnect node */
DBG printf("remove link %d/%d->%d/%d from tree 1\n", pos%w->width,pos/w->width, newpos%w->width,newpos/w->width);
w->flags1[pos] &= ~(bit[dir]);
w->flags1[newpos] &= 0x0f|ACTIVE;
bool_op(w, w->flags1, newpos, ~IN_TREE, 0);
/* try to reconnect the path to some other tree part */
if(reconnect(w, w->flags1, newpos, 0)) {
bool_op(w, w->flags1, newpos, ~0, IN_TREE);
} else {
destroy_subtree(w, w->flags1, newpos, q1, w->pos1);
break;
}
}
}
for(t=path->length-1;t>0 && !path->firsthalf[t-1];t--) {
int pos = path->pos[t];
int newpos = path->pos[t-1];
int dir = inv[path->dir[t-1]];
int newpos2 = pos+w->add[dir];
assert(newpos == newpos2);
if(!map->weight[inv[dir]][newpos]) {
/* disconnect node */
DBG printf("remove link %d/%d->%d/%d from tree 2\n", pos%w->width,pos/w->width, newpos%w->width,newpos/w->width);
w->flags2[pos] &= ~(bit[dir]);
w->flags2[newpos] &= 0x0f|ACTIVE;
bool_op(w, w->flags2, newpos, ~IN_TREE, 0);
/* try to reconnect the path to some other tree part */
if(reconnect(w, w->flags2, newpos, 1)) {
bool_op(w, w->flags2, newpos, ~0, IN_TREE);
} else {
destroy_subtree(w, w->flags2, newpos, q2, w->pos2);
break;
}
}
}
}
static void check_map(map_t*map)
{
int x,y,d;
int val = 0;
for(x=0;x<map->width;x++) {
if(map->weight[DOWN][(map->height-1)*map->width+x])
val |= DOWN_FLAG;
if(map->weight[UP][0*map->width+x])
val |= UP_FLAG;
}
for(y=0;y<map->height;y++) {
if(map->weight[RIGHT][map->width-1+y*map->width])
val |= RIGHT_FLAG;
if(map->weight[LEFT][y*map->width])
val |= LEFT_FLAG;
}
if(val) {
fprintf(stderr, "Warning: The map hasn't proper edges (positive weights extend beyond the bitmap, %02x)\n", val);
fprintf(stderr, "I'm fixing this now, but you should be more careful.\n");
}
val = 0;
for(x=0;x<map->width;x++)
for(y=0;y<map->height;y++)
for(d=0;d<4;d++) {
if(map->weight[d]<=0)
val = 1;
}
if(val) {
fprintf(stderr, "Warning: The map has non-positive values\n");
}
make_map_borders(map);
}
static int check3path(graphcut_workspace_t*w, int x1, int y1, int x2, int y2, int x3, int y3, int xfirst1, int xfirst2)
{
map_t*map = w->map;
int l = abs(x1-x2) + abs(y1-y2) + abs(x2-x3) + abs(y2-y3) + 1;
path_t* path = path_new(l);
int x = x1;
int y = y1;
int pos = y1*map->width+x1;
int i = 0;
int dir;
dir = xfirst1?(x1<x2?RIGHT:LEFT):(y1<y2?DOWN:UP);
if(xfirst1 && (x!=x2) || !xfirst1 && (y!=y2)) {
if(map->weight[dir][pos] <= 0) {
path_delete(path);
return 0;
}
assert(i<path->length);
path->pos[i] = pos;
path->dir[i] = dir;
i++;
x += xadd[dir];
y += yadd[dir];
pos += w->add[dir];
}
dir = (!xfirst1)?(x1<x2?RIGHT:LEFT):(y1<y2?DOWN:UP);
while(x!=x2 || y!=y2) {
if(map->weight[dir][pos] <= 0) {
path_delete(path);
return 0;
}
assert(i<path->length);
path->pos[i] = pos;
path->dir[i] = dir;
i++;
x += xadd[dir];
y += yadd[dir];
pos += w->add[dir];
}
dir = xfirst2?(x2<x3?RIGHT:LEFT):(y2<y3?DOWN:UP);
while(xfirst2 && (x!=x3) || !xfirst1 && (y!=y3)) {
if(map->weight[dir][pos] <= 0) {
path_delete(path);
return 0;
}
assert(i<path->length);
path->pos[i] = pos;
path->dir[i] = dir;
i++;
x += xadd[dir];
y += yadd[dir];
pos += w->add[dir];
}
dir = (!xfirst2)?(x2<x3?RIGHT:LEFT):(y2<y3?DOWN:UP);
while(x!=x3 || y!=y3) {
if(map->weight[dir][pos] <= 0) {
path_delete(path);
return 0;
}
assert(i<path->length);
path->pos[i] = pos;
path->dir[i] = dir;
i++;
x += xadd[dir];
y += yadd[dir];
pos += w->add[dir];
}
path->pos[i] = pos;
path->dir[i] = 4;
i++;
assert(i == path->length);
return decrease_weights(map, path);
}
static int preprocess(graphcut_workspace_t*w, int x1, int y1, int x2, int y2)
{
int xmid,ymid;
int sum = 0;
for(ymid=0;ymid<w->map->height;ymid++)
for(xmid=0;xmid<w->map->width;xmid++) {
sum += check3path(w, x1, y1, xmid, ymid, x2, y2, 0, 0);
sum += check3path(w, x1, y1, xmid, ymid, x2, y2, 0, 1);
sum += check3path(w, x1, y1, xmid, ymid, x2, y2, 1, 0);
sum += check3path(w, x1, y1, xmid, ymid, x2, y2, 1, 1);
}
return sum;
}
unsigned char* find_cut(map_t*map, int x1, int y1, int x2, int y2)
{
int pos1 = y1*map->width+x1;
int pos2 = y2*map->width+x2;
int max_flow = 0;
assert(pos1 != pos2);
graphcut_workspace_t* w = graphcut_workspace_new(map, map->width, map->height, pos1, pos2);
int preprocess_flow = 0;
#ifdef PREPROCESS
preprocess_flow = preprocess(w, x1, y1, x2, y2);
max_flow += preprocess_flow;
#endif
posqueue_addpos(w->queue1, pos1); w->flags1[pos1] |= ACTIVE|IN_TREE;
posqueue_addpos(w->queue2, pos2); w->flags2[pos2] |= ACTIVE|IN_TREE;
check_map(map);
while(1) {
path_t*path;
while(1) {
char done1=0,done2=0;
int p1 = posqueue_extract(w->queue1);
DBG printf("extend 1 from %d/%d\n", p1%w->width, p1/w->width);
if(p1<0) {
int t;
/* convert flags1 to map */
unsigned char*result = w->flags1;
for(t=0;t<w->size;t++) {
if(w->flags1[t]&IN_TREE) result[t] = 1;
else result[t] = 0;
}
w->flags1 = 0;
graphcut_workspace_delete(w);
printf("max flow: %d (%d (%.2f%%) from preprocessing)\n", max_flow, preprocess_flow, preprocess_flow*100.0 / max_flow);
return result;
}
path = expand_pos(w, w->queue1, p1, 0, w->flags1, w->flags2);
DBG workspace_print(w);
if(path)
break;
#ifdef TWOTREES
int p2 = posqueue_extract(w->queue2);
DBG printf("extend 2 from %d/%d\n", p2%w->width, p2/w->width);
if(p2<0) {
int t;
/* convert flags2 to map */
unsigned char*result = w->flags2;
for(t=0;t<w->size;t++) {
if(w->flags2[t]&IN_TREE) result[t] = 0;
else result[t] = 1;
}
w->flags2 = 0;
graphcut_workspace_delete(w);
printf("max flow: %d (%d (%.2f%%) from preprocessing)\n", max_flow, preprocess_flow, preprocess_flow*100.0 / max_flow);
return result;
}
path = expand_pos(w, w->queue2, p2, 1, w->flags2, w->flags1);
DBG workspace_print(w);
if(path)
break;
#endif
}
DBG printf("found connection between tree1 and tree2\n");
DBG path_print(path, w->width);
DBG printf("decreasing weights\n");
max_flow += decrease_weights(map, path);
DBG workspace_print(w);
DBG printf("destroying trees\n");
combust_tree(w, w->queue1, w->queue2, path);
DBG workspace_print(w);
path_delete(path);
}
}
#ifdef MAIN
#define DIM 512
static int test_small()
{
weight_t weight[4][16] =
{{3,1,2,0, //right
2,4,1,0,
3,3,3,0,
4,1,4,0},
{0,0,0,0, //up
4,2,3,2,
1,3,7,5,
1,2,5,1},
{0,3,3,3, //left
0,3,3,3,
0,3,1,3,
0,1,1,1},
{1,5,1,1, //down
1,1,1,1,
1,3,1,3,
0,0,0,0},
};
map_t map;
map.width = 4;
map.height = 4;
map.weight[RIGHT] = weight[0];
map.weight[UP] = weight[1];
map.weight[LEFT] = weight[2];
map.weight[DOWN] = weight[3];
map_save(&map, "smallmap.tst");
DBG printf("RIGHT: %02x %02x\n", RIGHT<<6, bit[RIGHT]);
DBG printf("UP: %02x %02x\n", UP<<6, bit[UP]);
DBG printf("LEFT: %02x %02x\n", LEFT<<6, bit[LEFT]);
DBG printf("DOWN: %02x %02x\n", DOWN<<6, bit[DOWN]);
DBG printf("\n");
find_cut(&map, 0, 0, 3, 3);
}
void test_big()
{
weight_t *(weight[4]);
weight[0] = malloc(sizeof(int)*DIM*DIM);
weight[1] = malloc(sizeof(int)*DIM*DIM);
weight[2] = malloc(sizeof(int)*DIM*DIM);
weight[3] = malloc(sizeof(int)*DIM*DIM);
int t;
for(t=0;t<DIM*DIM;t++) {
weight[0][t] = lrand48() % 256;
weight[1][t] = lrand48() % 256;
weight[2][t] = lrand48() % 256;
weight[3][t] = lrand48() % 256;
}
for(t=0;t<DIM;t++) {
weight[DOWN][(DIM-1)*DIM+t] = 0;
weight[UP][t] = 0;
weight[RIGHT][DIM-1+t*DIM] = 0;
weight[LEFT][t*DIM] = 0;
}
map_t map;
map.width = DIM;
map.height = DIM;
map.weight[0] = weight[0];
map.weight[1] = weight[1];
map.weight[2] = weight[2];
map.weight[3] = weight[3];
find_cut(&map, 0,0, DIM-1, DIM-1);
find_cut(&map, (DIM*1/3),(DIM*1/3), (DIM*2/3),(DIM*2/3)); // at 1/3,1/3 to 2/3,2/3
}
#include "image.h"
void test_matrix()
{
matrix_t* m = matrix_new(5,4);
double data[5*4] = { 1.0, 2.0, 3.0, 4.0, 5.0,
3.0, 4.0, 2.0, 1.0, 6.0,
4.0, 3.0, 1.0, 4.0, 3.0,
4.0, 2.0, 5.0, 3.0, 2.0};
memcpy(m->data, data, sizeof(data));
map_t*map = map_from_matrix(m);
unsigned char*cut = find_cut(map, 1,1, 3,2);
}
void test_image_extract()
{
image_t*img1 = image_load("../images/flower_tiny.png");