CImage *ReadCImage(char *filename)
{
CImage *cimg=NULL;
FILE *fp=NULL;
char type[10];
int i,ncols,nrows,n;
char z[256];
fp = fopen(filename,"rb");
if (fp == NULL){
fprintf(stderr,"Cannot open %s\n",filename);
exit(-1);
}
fscanf(fp,"%s\n",type);
if((strcmp(type,"P6")==0)){
NCFgets(z,255,fp);
sscanf(z,"%d %d\n",&ncols,&nrows);
n = ncols*nrows;
NCFgets(z,255,fp);
sscanf(z,"%d\n",&i);
cimg = CreateCImage(ncols,nrows);
for (i=0; i < n; i++){
cimg->C[0]->val[i] = fgetc(fp);
cimg->C[1]->val[i] = fgetc(fp);
cimg->C[2]->val[i] = fgetc(fp);
}
fclose(fp);
}else{
fprintf(stderr,"Input image must be P6\n");
exit(-1);
}
return(cimg);
}
CImage *DrawLabeledRegions(Image *img, Image *label){
CImage *border=CreateCImage(img->ncols,img->nrows);
int x,y,k,p,q,u,v;
AdjRel *A;
A = Circular(1.0);
for(y=0;y<img->nrows;y++){
for(x=0;x<img->ncols;x++){
p = x + img->tbrow[y];
border->C[0]->val[p]=
border->C[1]->val[p]=border->C[2]->val[p]=img->val[p];
for(k=1;k<A->n;k++){
u = x+A->dx[k];
v = y+A->dy[k];
if(ValidPixel(img,u,v)){
q= u + img->tbrow[v];
if (label->val[p] != label->val[q]){
border->C[0]->val[p]=255;
border->C[1]->val[p]=0;
border->C[2]->val[p]=0;
break;
}
}
}
}
}
DestroyAdjRel(&A);
return(border);
}
CImage *BlendImages(CImage *cimg1, CImage *cimg2, float alpha1, float alpha2)
{
CImage *cimg3=CreateCImage(cimg1->C[0]->ncols,cimg1->C[0]->nrows);
int p,n=cimg1->C[0]->ncols*cimg1->C[0]->nrows;
for (p=0; p < n; p++) {
cimg3->C[0]->val[p] = alpha1*cimg1->C[0]->val[p] + alpha2*cimg2->C[0]->val[p];
cimg3->C[1]->val[p] = alpha1*cimg1->C[1]->val[p] + alpha2*cimg2->C[1]->val[p];
cimg3->C[2]->val[p] = alpha1*cimg1->C[2]->val[p] + alpha2*cimg2->C[2]->val[p];
}
return(cimg3);
}
CImage *CImageLABtoXYZ(CImage *cimg)
{
CImage *ncimg=NULL;
int p,n,i;
ncimg = CreateCImage(cimg->C[0]->ncols,cimg->C[0]->nrows);
n = ncimg->C[0]->ncols*ncimg->C[0]->nrows;
for (p=0; p < n; p++){
i = triplet(cimg->C[0]->val[p],cimg->C[1]->val[p],cimg->C[2]->val[p]);
i = LAB2XYZ(i);
ncimg->C[0]->val[p]=t0(i);
ncimg->C[1]->val[p]=t1(i);
ncimg->C[2]->val[p]=t2(i);
}
return(ncimg);
}
CImage *ColorizeImage(Image *img, float R, float G, float B)
{
CImage *cimg=CreateCImage(img->ncols,img->nrows);
float Cb,Cr,Y;
int Imax,p,n=img->ncols*img->nrows;
Imax = MAX(MaximumValue(img),1);
Cb = -0.148*R-0.291*G+0.439*B+128.0/255.;
Cr = 0.439*R-0.368*G-0.071*B+128.0/255.;
for (p=0; p < n; p++) {
Y = ((float)img->val[p]/Imax);
R=296.82*(Y-0.062745098039)+
406.98*(Cr-0.50196078431);
G=296.82*(Y-0.062745098039)-
207.315*(Cr-0.50196078431)-
99.96*(Cb-0.50196078431);
B=296.82*(Y-0.062745098039)+
514.335*(Cb-0.50196078431);
if (R<0.0) R=0.0;
if (G<0.0) G=0.0;
if (B<0.0) B=0.0;
if (R>255.0) R=255.0;
if (G>255.0) G=255.0;
if (B>255.0) B=255.0;
cimg->C[0]->val[p]=(int)(R);
cimg->C[1]->val[p]=(int)(G);
cimg->C[2]->val[p]=(int)(B);
}
return(cimg);
}
CImage *CLinearStretch(CImage *cimg, int f1, int f2, int g1, int g2)
{
CImage *simg=NULL;
int p,n;
float a,R,G,B,Y,Cb,Cr,yf1,yf2,yg1,yg2;
simg = CreateCImage(cimg->C[0]->ncols,cimg->C[0]->nrows);
n = simg->C[0]->ncols*simg->C[0]->nrows;
if (f1 != f2) {
a = ((float)(g2-g1))/(f2-f1);
}
else {
a = INT_MAX;
}
yf1 = (float)f1/255.;
yf2 = (float)f2/255.;
yg1 = (float)g1/255.;
yg2 = (float)g2/255.;
for (p=0; p < n; p++){
R = (float)cimg->C[0]->val[p]/255.;
G = (float)cimg->C[1]->val[p]/255.;
B = (float)cimg->C[2]->val[p]/255.;
Y = 0.257*R+0.504*G+0.098*B+16.0/255.;
Cb =-0.148*R-0.291*G+0.439*B+128.0/255.;
Cr = 0.439*R-0.368*G-0.071*B+128.0/255.;
if (Y < yf1)
Y = yg1;
else
if (Y > yf2)
Y = yg2;
else {
if (a != INT_MAX)
Y = (a*(Y-yf1)+yg1);
else{
Y = yg2;
}
}
R= 296.82*(Y-0.062745098039)+\
406.98*(Cr-0.50196078431);
G =296.82*(Y-0.062745098039)-\
207.315*(Cr-0.50196078431)-\
99.96*(Cb-0.50196078431);
B= 296.82*(Y-0.062745098039)+\
514.335*(Cb-0.50196078431);
if (R<0.0) R=0.0;
if (G<0.0) G=0.0;
if (B<0.0) B=0.0;
if (R>255.0) R=255.0;
if (G>255.0) G=255.0;
if (B>255.0) B=255.0;
simg->C[0]->val[p]=(int)(R);
simg->C[1]->val[p]=(int)(G);
simg->C[2]->val[p]=(int)(B);
}
return(simg);
}