151 lines
3.4 KiB
C
151 lines
3.4 KiB
C
#include <getopt.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include "helpers.h"
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int main(int argc, char *argv[])
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{
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// Define allowable filters
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char *filters = "bgrs";
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// Get filter flag and check validity
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char filter = getopt(argc, argv, filters);
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if (filter == '?')
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{
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printf("Invalid filter.\n");
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return 1;
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}
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// Ensure only one filter
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if (getopt(argc, argv, filters) != -1)
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{
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printf("Only one filter allowed.\n");
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return 2;
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}
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// Ensure proper usage
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if (argc != optind + 2)
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{
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printf("Usage: ./filter [flag] infile outfile\n");
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return 3;
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}
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// Remember filenames
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char *infile = argv[optind];
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char *outfile = argv[optind + 1];
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// Open input file
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FILE *inptr = fopen(infile, "r");
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if (inptr == NULL)
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{
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printf("Could not open %s.\n", infile);
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return 4;
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}
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// Open output file
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FILE *outptr = fopen(outfile, "w");
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if (outptr == NULL)
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{
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fclose(inptr);
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printf("Could not create %s.\n", outfile);
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return 5;
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}
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// Read infile's BITMAPFILEHEADER
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BITMAPFILEHEADER bf;
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fread(&bf, sizeof(BITMAPFILEHEADER), 1, inptr);
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// Read infile's BITMAPINFOHEADER
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BITMAPINFOHEADER bi;
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fread(&bi, sizeof(BITMAPINFOHEADER), 1, inptr);
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// Ensure infile is (likely) a 24-bit uncompressed BMP 4.0
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if (bf.bfType != 0x4d42 || bf.bfOffBits != 54 || bi.biSize != 40 ||
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bi.biBitCount != 24 || bi.biCompression != 0)
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{
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fclose(outptr);
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fclose(inptr);
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printf("Unsupported file format.\n");
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return 6;
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}
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// Get image's dimensions
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int height = abs(bi.biHeight);
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int width = bi.biWidth;
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// Allocate memory for image
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RGBTRIPLE(*image)[width] = calloc(height, width * sizeof(RGBTRIPLE));
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if (image == NULL)
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{
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printf("Not enough memory to store image.\n");
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fclose(outptr);
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fclose(inptr);
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return 7;
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}
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// Determine padding for scanlines
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int padding = (4 - (width * sizeof(RGBTRIPLE)) % 4) % 4;
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// Iterate over infile's scanlines
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for (int i = 0; i < height; i++)
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{
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// Read row into pixel array
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fread(image[i], sizeof(RGBTRIPLE), width, inptr);
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// Skip over padding
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fseek(inptr, padding, SEEK_CUR);
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}
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// Filter image
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switch (filter)
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{
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// Blur
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case 'b':
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blur(height, width, image);
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break;
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// Grayscale
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case 'g':
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grayscale(height, width, image);
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break;
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// Reflection
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case 'r':
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reflect(height, width, image);
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break;
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// Sepia
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case 's':
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sepia(height, width, image);
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break;
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}
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// Write outfile's BITMAPFILEHEADER
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fwrite(&bf, sizeof(BITMAPFILEHEADER), 1, outptr);
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// Write outfile's BITMAPINFOHEADER
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fwrite(&bi, sizeof(BITMAPINFOHEADER), 1, outptr);
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// Write new pixels to outfile
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for (int i = 0; i < height; i++)
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{
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// Write row to outfile
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fwrite(image[i], sizeof(RGBTRIPLE), width, outptr);
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// Write padding at end of row
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for (int k = 0; k < padding; k++)
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{
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fputc(0x00, outptr);
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}
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}
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// Free memory for image
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free(image);
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// Close files
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fclose(inptr);
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fclose(outptr);
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return 0;
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}
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