Image Processing using C-Programming

Image: 

• An image is a two-dimensional (2-D) array of pixels.
• There are mainly two types of Image.

1. R-G-B Channel Image: The R-G-B Images are formed by three primary channel called a color image. Red, Green and Blue are three channels in a color image.
   
2. Single Channel Image: Monochrome Image that has pixel's intensity ranging from 0 to 255 is called Single Channel Image. 

Example:

Figure 1. A Monochrome Image

Image Contrast Stretching using C-Programming.

Contrast Stretching in Image Processing:

• It is an image processing technique for low-contrast images.
• The low-contrast images can result from poor illumination and wrong setting of a lens aperture during image acquisition.
• Contrast stretching is a process that expands the range of intensity levels in an image.

#include<stdio.h>

#include<stdlib.h>

#include<math.h>

void main()

{

int i,j,row,col,max,pix,v=0,max1=0,min=1000;

char c[10],a[100];

FILE *p,*q;

p=fopen("cot.pgm","r");

fscanf(p,"%s\n", c);

fscanf(p,"%[^\n]\n", a);

fscanf(p,"%d %d\n", &col ,&row);

fscanf(p,"%d\n",&max);

int m[row][col],m1[row][col],m2[256];

for(i=0;i<row;i++)

{

for(j=0;j<col;j++)

{

fscanf(p,"%d\n",&pix);

m[i][j]=pix;

if(max1<pix)

max1=pix;

if(min>pix)

min=pix;

}

}printf("%d %d\n", max1,min);

for(i=0;i<row;i++)

{

for(j=0;j<col;j++)

{

m[i][j]=((255*(m[i][j]-min)/(max1-min)));

}

}

q=fopen("d31.pgm","w");

fprintf(q,"%s\n",c);

fprintf(q,"%s\n",a);

fprintf(q,"%d %d\n", col, row);

fprintf(q,"%d\n",max);

for(i=0;i<row;i++)

{

for(j=0;j<col;j++)

{

pix=m[i][j];

fprintf(q,"%d\n",pix);

}

}

fclose(p);

fclose(q);

}