Not a member of Pastebin yet?
Sign Up,
it unlocks many cool features!
- #include <stdio.h>
- #include <stdlib.h>
- #include "bmp.h"
- int main(int argc, char* argv[])
- {
- // ensure proper usage
- if (argc != 4)
- {
- printf("Usage: ./resize n infile outfile\n");
- return 1;
- }
- // remember filenames
- int n = atoi (argv[1]);
- char* infile = argv[2];
- char* outfile = argv[3];
- if (n<=0||n>100)
- {
- printf("n must be between 1 and 100");
- return 5;
- }
- // open input file
- FILE* inptr = fopen(infile, "r");
- if (inptr == NULL)
- {
- printf("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,new_bf;
- fread(&bf, sizeof(BITMAPFILEHEADER), 1, inptr);
- // read infile's BITMAPINFOHEADER
- BITMAPINFOHEADER bi, new_bi;
- fread(&bi, sizeof(BITMAPINFOHEADER), 1, inptr);
- // 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;
- }
- new_bf=bf;
- new_bi=bi;
- new_bi.biWidth=bi.biWidth*n;
- new_bi.biHeight=bi.biHeight*n;
- // determine padding for scanlines
- int padding = (4 - (bi.biWidth * sizeof(RGBTRIPLE)) % 4) % 4;
- int new_padding = (4-(new_bi.biWidth * sizeof(RGBTRIPLE))%4)%4;
- //size of new image.
- new_bi.biSizeImage = (bi.biWidth* sizeof (RGBTRIPLE) + new_padding) * (abs(new_bi.biHeight));
- new_bf.bfSize = (bf.bfSize - bi.biSizeImage + new_bi.biSizeImage);
- // write outfile's BITMAPFILEHEADER
- fwrite(&new_bf, sizeof(BITMAPFILEHEADER), 1, outptr);
- // write outfile's BITMAPINFOHEADER
- fwrite(&new_bi, sizeof(BITMAPINFOHEADER), 1, outptr);
- // iterate over infile's scanlines
- for (int i = 0, biHeight = abs(bi.biHeight); i < biHeight; i++)
- {
- //iterate n times.
- for (int m=0;m<n;m++)
- {
- // 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);
- for (int f=0;f<n;f++)
- {
- // write RGB triple to outfile
- fwrite(&triple, sizeof(RGBTRIPLE), 1, outptr);
- }
- // then add it back (to demonstrate how)
- for (int k = 0; k < new_padding; k++)
- {
- fputc(0x00, outptr);
- //start from scale line again
- if (m<n-1)
- {
- fseek(inptr, -bi.biWidth * sizeof(RGBTRIPLE), SEEK_CUR);
- }
- }
- }
- fseek(inptr, padding, SEEK_CUR);
- }
- }
- // close infile
- fclose(inptr);
- // close outfile
- fclose(outptr);
- // that's all folks
- return 0;
- }
Add Comment
Please, Sign In to add comment