resize.c - shared from CS50 IDE

resize.c

/**
 * Copies a BMP piece by piece, just because.
 */
       
#include <stdio.h>
#include <stdlib.h>
#include<cs50.h>
#include<math.h>

#define min(a,b) \
  ({ typeof (a) _a = (a); \
      typeof (b) _b = (b); \        //Min defined
    _a < _b ? _a : _b; })

#include "bmp.h"

int main(int argc, char *argv[])
{
    // ensure proper usage
    if (argc != 4)
    {
        fprintf(stderr, "Usage: ./copy f infile outfile\n");
        return 1;
    }
    
    
    float f=atof(argv[1]);
    //float f=sscanf(argv[1], " %f", &f); It can also be used
     //exit if f is invalid
    if(f > 100.0 || f < 0.0) {
        fprintf(stderr, "Usage: ./resize f infile outfile\n");
        return 1;
    }
    

    // remember filenames
    char *infile = argv[2];
    char *outfile = argv[3];

    // open input file 
    FILE *inptr = fopen(infile, "r");
    if (inptr == NULL)
    {
        fprintf(stderr, "Could not open %s.\n", infile);
        return 2;
    }

    // open output file
    FILE *outptr = fopen(outfile, "w");
    if (outptr == NULL)
    {
        fclose(inptr);
        fprintf(stderr, "Could not create %s.\n", outfile);
        return 3;
    }

    // read infile's BITMAPFILEHEADER
    BITMAPFILEHEADER bf;
    BITMAPFILEHEADER bof;
    fread(&bf, sizeof(BITMAPFILEHEADER), 1, inptr);
    
    bof=bf;

    // read infile's BITMAPINFOHEADER
    BITMAPINFOHEADER bi;
    BITMAPINFOHEADER boi;
    fread(&bi, sizeof(BITMAPINFOHEADER), 1, inptr);
    
    boi=bi;

    // ensure infile is (likely) a 24-bit uncompressed BMP 4.0
    if (bf.bfType != 0x4d42 || bf.bfOffBits != 54 || bi.biSize != 40 || 
        bi.biBitCount != 24 || bi.biCompression != 0)
    {
        fclose(outptr);
        fclose(inptr);
        fprintf(stderr, "Unsupported file format.\n");
        return 4;
    }
    
     // determine padding for scanlines
    int padding = (4 - (bi.biWidth * sizeof(RGBTRIPLE)) % 4) % 4;
    
    //determining width
    boi.biWidth=floor(bi.biWidth*f);
    
    //determining height by checking top down and bottom up and compliang to top down
    boi.biHeight=floor(((bi.biHeight>0)?-bi.biHeight:bi.biHeight)*f);
    
    //calculating padding for new file
    int paddingNew = (4 - (boi.biWidth * sizeof(RGBTRIPLE)) % 4) % 4;
    
    //new size of image excluding headers
    boi.biSizeImage=(abs(boi.biHeight)*((boi.biWidth* sizeof(RGBTRIPLE))+paddingNew));
    
    //determining new bfsize
    bof.bfSize=boi.biSizeImage + sizeof(BITMAPFILEHEADER)+sizeof(BITMAPINFOHEADER);

    // write outfile's BITMAPFILEHEADER
    fwrite(&bof, sizeof(BITMAPFILEHEADER), 1, outptr);

    // write outfile's BITMAPINFOHEADER
    fwrite(&boi, sizeof(BITMAPINFOHEADER), 1, outptr);
    
    //declaring outfile scanline array
   RGBTRIPLE pixel[abs(bi.biHeight)][bi.biWidth];
   
    if(bi.biHeight<0)
    {

    // iterate over infile's scanlines
    for (int i = 0; i< abs(bi.biHeight) ; i++)
    {
        // iterate over pixels in scanline
        for (int j = 0; j < bi.biWidth; j++)
        {
            // temporary storage
          //  RGBTRIPLE triple;

            // read RGB triple from infile
           // fread(&triple, sizeof(RGBTRIPLE), 1, inptr);
            fread(&(pixel[i][j]), sizeof(RGBTRIPLE), 1, inptr);
            //pixel[i][j]=triple;

        }
        
        // skip over padding, if any
        fseek(inptr, padding, SEEK_CUR);
    }
    
         
    }
 
        else
    {
        for(int i=bi.biHeight-1; i>=0; i--)
        {
        for (int j = 0; j < bi.biWidth; j++)
        {
            // temporary storage
          //  RGBTRIPLE triple;

            // read RGB triple from infile
           // fread(&triple, sizeof(RGBTRIPLE), 1, inptr);
            fread(&(pixel[i][j]), sizeof(RGBTRIPLE), 1, inptr);
            //pixel[i][j]=triple;

        }

        // skip over padding, if any
        fseek(inptr, padding, SEEK_CUR);
        }

       
    }
    
    
    RGBTRIPLE outpixel[abs(boi.biHeight)][boi.biWidth];
    
    int row,col;
   if(f>1)
{
    for(int i=0; i<abs(bi.biHeight); i++)
    {
        row=floor(i*f);
        for(int t=row; t<row+floor(f);t++)
        {
        for(int j=0; j<bi.biWidth; j++)
          {
              col=ceil(j*f);                              //This block of code(Line : 155-171) doesn't work for f<1  #ISSUE
            for(int k=col; k<col+floor(f);k++)
            
             { outpixel[t][k]=pixel[i][j];}
            
          }
        
        }
    }
    
}
    else
{
     int r=0,c=0;

     for(int i=0; i<abs(boi.biHeight);)
     {
         for(int j=0; j<boi.biWidth;)
         {
             outpixel[i][j]=pixel[r][c];
             j++;
              c= min(c+floor(1.0/f), bi.biWidth) ;  //Use of function min
         }
         r= min(r+floor(1.0/f),abs(bi.biHeight)) ;
         i++;
     }


}


/*
    int indI, indJ;
    for(int i = 0; i < abs(bi.biHeight); i++) {
        indI = floor(i*f);
         for(int j = 0; j < bi.biWidth; j++) {
            indJ = ceil(f*j);
            outpixel[indI][indJ] = pixel[i][j];
            for(int k = floor(f) - 1; k > 0; k--) {
                outpixel[indI][indJ + k] = pixel[i][j];
            }
}                                                                             //This block of Code(Line : 172-191) cleared check50 but it doesn't work fine when applied to large.bmp
        for(int l = floor(f) - 1; l >= 0; l--) {
            for(int j = 0; j < bi.biWidth; j++) {
                indJ = ceil(f*j);
                outpixel[indI + l][indJ] = pixel[i][j];
                for(int k = floor(f) - 1; k > 0; k--) {
                    outpixel[indI + l][indJ + k] = pixel[i][j];
                }
            }
        }
    }
    */
     // writing to output file after adding padding
     for(int i=0; i<abs(boi.biHeight); i++)
    {
        for(int j=0; j<boi.biWidth; j++)
        {
            fwrite(&outpixel[i][j], sizeof(RGBTRIPLE), 1, outptr);
        
        }
        
        for (int k = 0; k < paddingNew; k++)
          {
            fputc(0x00, outptr);
          } 
     }    

    // close infile
    fclose(inptr);    

    // close outfile
    fclose(outptr);

    // success
    return 0;

}