/*Bilinear Interpolation Algorithm*/
void bipol(PGMData* Image)
{
int newrow, newcol;
float sx,sy;
printf("\n\t ***** Bilinear Interpolation ****** ");
printf("\nEnter the X-scale factor between 0.5 and 2.0\t :");
scanf("%f0.2",&sx);
printf("\nEnter the Y-scale factor between 0.5 and 2.0\t :");
scanf("%f0.2",&sy);
newcol = int((sx) * imgdata->row);
newrow = int((sy) * imgdata->col);
newi=&newImage;
newi->row=newrow;
newi->col=newcol;
newi->max_gray=orig->max_gray;
newi->matrix = allocate_dynamic_matrix(Image->row,newi->col);
newj=&newImage2;
newj->row=newrow;
newj->col=newcol;
newj->max_gray=orig->max_gray;
newj->matrix = allocate_dynamic_matrix(newj->row,newj->col);
printf("The Scaled Image is of size %d X %d",newj->row,newj->col);
float x=0,y=0;
float dx,dy,dyL,dxL;
float value;
int u1=0,v1=0,u2=0,v2=0;
for(int m=1;m<Image->row-1;m++)
{
for(int n=1;n<newi->col-1;n++)
{
/*Interpolating column number*/
y = (1/sx)*n;
dy = abs(y - floor(y));
dyL = 1 - dy;
v1 = floor(y);
v2 = ceil(y);
value = (dyL*Image->matrix[m][v1]) + (dy*Image->matrix[m][v2]);
newi->matrix[m][n]= value;
}
}
for(int m=1;m<newi->row-1;m++)
{
/*Interpolating row number*/
x = (1/sy) * m;
dx = abs(x - floor(x));
dxL = 1 - dx;
u1 = floor(x);
u2 = ceil(x);
for(int n=1;n<newj->col-1;n++)
{
value = (dxL*newi->matrix[u1][n]) + (dx*newi->matrix[u2][n]);
newj->matrix[m][n] = value;
}
}
}
/*Nearest Neighbor Algorithm*/
void near(PGMData * Image)
{
int newrow, newcol;
float sx,sy;
//int x=0,y=0;
printf("\n\t *****Nearest Neighbour ****** ");
printf("\nEnter the X-scale factor between 0.5 and 2.0\t :");
scanf("%f0.2",&sx);
printf("\nEnter the Y-scale factor between 0.5 and 2.0\t :");
scanf("%f0.2",&sy);
newcol = int((sx) * imgdata->row);
newrow = int((sy) * imgdata->col);
newi=&newImage;
newi->row=newrow;
newi->col=newcol;
newi->max_gray=imgdata->max_gray;
newi->matrix = allocate_dynamic_matrix(Image->row,newi->col);
newj=&newImage2;
newj->row=newrow;
newj->col=newcol;
newj->max_gray=orig->max_gray;
newj->matrix = allocate_dynamic_matrix(newj->row,newj->col);
printf("The Scaled Image is of size %d X %d",newj->row,newj->col);
/*Calculation for columns*/
float x=0,y=0;
int u=0,v=0;
for(int m=0;m<Image->row;m++)
{
for(int n=0;n<newi->col;n++)
{
/*Rounding off column number*/
y = (1/sx)*n;
v = int(y);
newi->matrix[m][n]=Image->matrix[m][v];
}
}
/*Calculation for rows*/
for(int m=0;m<newi->row;m++)
{
/*Rounding off row number*/
x = (1/sy) * m;
u = int(x);
for(int n=1;n<newj->col;n++)
{
newj->matrix[m][n]=newi->matrix[u][n];
}
}
}
/*for reading:*/
PGMData* read_PGM(const char *file_name, PGMData *data)
{
FILE *pgmFile;
char version[3];
int i, j;
int lo, hi;
pgmFile = fopen(file_name, "rb");
if (pgmFile == NULL)
{
perror("cannot open file to read");
exit(EXIT_FAILURE);
}
fgets(version, sizeof(version), pgmFile);
if (strcmp(version, "P5"))
{
fprintf(stderr, "Wrong file type!\n");
exit(EXIT_FAILURE);
}
skip_comments(pgmFile);
fscanf(pgmFile, "%d", &data->col);
skip_comments(pgmFile);
fscanf(pgmFile, "%d", &data->row);
skip_comments(pgmFile);
fscanf(pgmFile, "%d", &data->max_gray);
fgetc(pgmFile);
data->matrix = allocate_dynamic_matrix(data->row, data->col);
if (data->max_gray > 255)
for (i = 0; i < data->row; ++i)
for (j = 0; j < data->col; ++j)
{
hi = fgetc(pgmFile);
lo = fgetc(pgmFile);
data->matrix[i][j] = (hi << 8) + lo;
}
else
for (i = 0; i < data->row; ++i)
for (j = 0; j < data->col; ++j)
{
lo = fgetc(pgmFile);
data->matrix[i][j] = lo;
}
fclose(pgmFile);
return data;
}
/*function to read PGM file*/
PGMData* readPGM(const char *file_name, PGMData *data)
{
FILE *pgmFile;
char version[3];
int i, j;
int lo, hi;
/*open a input file to read*/
pgmFile = fopen(file_name, "rb");
if (pgmFile == NULL) {
perror("cannot open file to read");
getchar();
exit(EXIT_FAILURE);
}
/*check for P5 version*/
fgets(version, sizeof(version), pgmFile);
if (strcmp(version, "P5")) {
fprintf(stderr, "Wrong file type!\n");
getchar();
exit(EXIT_FAILURE);
}
/*store values of column , row and maxgrey in structures*/
SkipComments(pgmFile);
fscanf(pgmFile, "%d", &data->col);
SkipComments(pgmFile);
fscanf(pgmFile, "%d", &data->row);
SkipComments(pgmFile);
fscanf(pgmFile, "%d", &data->max_gray);
fgetc(pgmFile);
/*store the higher byte in dynamic matrix*/
data->matrix = allocate_dynamic_matrix(data->row, data->col);
if (data->max_gray > 255)
for (i = 0; i < data->row; ++i)
for (j = 0; j < data->col; ++j) {
hi = fgetc(pgmFile);
lo = fgetc(pgmFile);
data->matrix[i][j] = (hi << 8) + lo;
}
else
/*store the lower byte in dynamic matrix*/
for (i = 0; i < data->row; ++i)
for (j = 0; j < data->col; ++j) {
lo = fgetc(pgmFile);
data->matrix[i][j] = lo;
}
/*close and return*/
fclose(pgmFile);
return data;
}
/*Main program*/
void main()
{
char filename[100],ch,ans;
int selection,width,height;
const char * source_fileName;
const char * modified_fileName = "output.pgm";
const char * inte_fileName = "intermediate.pgm";
printf("\n************WELCOME***************");
printf("\nEnter image file to read(pgm format) : ");
scanf("%s",&filename);
source_fileName=filename;
printf("Reading image \"%s\" ...\n", source_fileName);
do
{
orig = readPGM(source_fileName, orig);
printf("\nDo you want to Enter Window size for the image?(Y/N)");
printf("\nEnter your ans here:");
getchar();
scanf("%c",&ans);
if(ans == 'y' || ans =='Y')
{
printf("\nEnter width < %d of window here:",orig->row);
scanf("%d",&width);
printf("\nEnter height < %d of window here:",orig->col);
scanf("%d",&height);
imgdata=&ImageData;
imgdata->row=width;
imgdata->col=height;
imgdata->max_gray=orig->max_gray;
imgdata->matrix = allocate_dynamic_matrix(imgdata->row,imgdata->col);
for(int m=0;m<width;m++)
for(int n=0;n<height;n++)
{
imgdata->matrix[m][n]=orig->matrix[m][n];
}
}
else
imgdata = orig;
printf("\n*********Image Scaling Options*************");
printf("\n\t1.Nearest Neighbour Method");
printf("\n\t2.Bilinear Interpolation");
printf("\nEnter your selection here:");
scanf("%d",&selection);
switch (selection)
{
case 1: near(orig);
break;
case 2: bipol(orig);
break;
default: printf("Invaild choice\n Exiting program...");
exit(1);
break;
}
writePGM(modified_fileName,newj);
writePGM(inte_fileName,imgdata);
printf("\nFile Writing complete");
printf("\nopening outputfile......");
/***** open a output file in openseeit ****/
char program[100] = "OpenSeeIt.exe ";
char *openme;
openme= strcat(program,modified_fileName);
system(openme);
printf("\nDo you want to continue?(Y/N)\nEnter your answer here:");
getchar();
ch=getchar();
}while(ch=='Y' || ch=='y');
}