Created
June 15, 2018 04:33
-
-
Save jcoryalvernaz/12e47b3005cd662a5fde0434b435c8aa to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
// Copies a BMP file | |
#include <stdio.h> | |
#include <stdlib.h> | |
#include "bmp.h" | |
int main(int argc, char *argv[]) | |
{ | |
// ensure proper usage | |
if (argc != 3) | |
{ | |
fprintf(stderr, "Usage: copy infile outfile\n"); | |
return 1; | |
} | |
// remember filenames | |
char *infile = argv[1]; | |
char *outfile = argv[2]; | |
// 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; | |
fread(&bf, sizeof(BITMAPFILEHEADER), 1, inptr); | |
// read infile's BITMAPINFOHEADER | |
BITMAPINFOHEADER 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; | |
} | |
// write outfile's BITMAPFILEHEADER | |
fwrite(&bf, sizeof(BITMAPFILEHEADER), 1, outptr); | |
// write outfile's BITMAPINFOHEADER | |
fwrite(&bi, sizeof(BITMAPINFOHEADER), 1, outptr); | |
// determine padding for scanlines | |
int padding = (4 - (bi.biWidth * sizeof(RGBTRIPLE)) % 4) % 4; | |
// iterate over infile's scanlines | |
for (int i = 0, biHeight = abs(bi.biHeight); i < 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); | |
//If rgbtriple is pure red, set it to white | |
if (triple.rgbtRed == 0xff && triple.rgbtBlue == 0x00 && triple.rgbtGreen == 0x00) | |
{ | |
triple.rgbtBlue = 0xff; | |
triple.rgbtGreen = 0xff; | |
} | |
//if rgbtriple is white, change it to black | |
if (triple.rgbtBlue == 0xff && triple.rgbtRed == 0xff && triple.rgbtGreen == 0xff) | |
{ | |
triple.rgbtBlue = 0x00; | |
triple.rgbtRed = 0x00; | |
triple.rgbtGreen = 0x00; | |
} | |
// write RGB triple to outfile | |
fwrite(&triple, sizeof(RGBTRIPLE), 1, outptr); | |
} | |
// skip over padding, if any | |
fseek(inptr, padding, SEEK_CUR); | |
// then add it back (to demonstrate how) | |
for (int k = 0; k < padding; k++) | |
{ | |
fputc(0x00, outptr); | |
} | |
} | |
// close infile | |
fclose(inptr); | |
// close outfile | |
fclose(outptr); | |
// success | |
return 0; | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment