Reading pattern from file and create a bmp image of that in C -
i want read text file using c language.here's file:-
you see there pattern in text content on file. 0 means nothing. 9 means black. there coloring scheme 0 9.
i have create bitmap image of , color according values in pattern. have adjust 0-256 color scheme. , final output shown below
now see pattern in content of text file opposite final output bitmap file (not necessary). darkness of colors in bitmap image according values in pattern of text content.
anyone tell me how achieve in c language.
i able create bmp file not according pattern in text file.
#include <stdio.h> #include <stdlib.h> int main() { char bitmap[1900]; // -- file header -- // // bitmap signature bitmap[0] = 0x42; bitmap[1] = 0x4d; // file size bitmap[2] = 58; // 40 + 14 + 12 bitmap[3] = 0; bitmap[4] = 0; bitmap[5] = 0; int i=0; // reserved field (in hex. 00 00 00 00) for(i = 6; < 10; i++) bitmap[i] = 0; // offset of pixel data inside image for(i = 10; < 14; i++) bitmap[i] = 0; // -- bitmap header -- // // header size bitmap[14] = 40; for(i = 15; < 18; i++) bitmap[i] = 0; // width of image bitmap[18] = 4; for(i = 19; < 22; i++) bitmap[i] = 0; // height of image bitmap[22] = 1; for(i = 23; < 26; i++) bitmap[i] = 0; // reserved field bitmap[26] = 1; bitmap[27] = 0; // number of bits per pixel bitmap[28] = 24; // 3 byte bitmap[29] = 0; // compression method (no compression here) for(i = 30; < 34; i++) bitmap[i] = 0; // size of pixel data bitmap[34] = 12; // 12 bits => 4 pixels bitmap[35] = 0; bitmap[36] = 0; bitmap[37] = 0; // horizontal resolution of image - pixels per meter (2835) bitmap[38] = 0; bitmap[39] = 0; bitmap[40] = 0b00110000; bitmap[41] = 0b10110001; // vertical resolution of image - pixels per meter (2835) bitmap[42] = 0; bitmap[43] = 0; bitmap[44] = 0b00110000; bitmap[45] = 0b10110001; // color pallette information for(i = 46; < 50; i++) bitmap[i] = 0; // number of important colors for(i = 50; < 54; i++) bitmap[i] = 0; // -- pixel data -- // for(i = 54; < 66; i++) bitmap[i] = 255; file *file; file = fopen("bitmap.bmp", "w+"); for(i = 0; < 66; i++) { fputc(bitmap[i], file); } fclose(file); return 0; }
here working code. not check case of error (input file badly formatted, example). put commentaries, though code not difficult understand.
#include <stdlib.h> #include <stdint.h> #include <assert.h> #include <string.h> #include <stdio.h> #include <stdbool.h> #include <errno.h> #include <ctype.h> #define bmp_assert(condition, message) \ { \ if (! (condition)) { \ fprintf(stderr, __file__ ":%d: %s: assertion `" #condition \ "` failed.\n\t: %s\n", __line__, __func__, message); \ exit(exit_failure); \ } \ } while (false) #define bmp_colormap_size 10 //////////////////////////////////////////////////////////////////////////////// // structs typedef struct __attribute__((__packed__)) bmp_color { uint8_t r, g, b; uint8_t :8; } bmp_color_t; typedef struct __attribute__((__packed__)) bmp_header_infos { uint32_t const info_size; uint32_t width; uint32_t height; uint16_t const planes; uint16_t const bpp; uint32_t const compression; uint32_t img_size; uint32_t const horz_resolution; uint32_t const vert_resolution; uint32_t const n_colors; uint32_t const n_important_colors; } bmp_header_infos_t; typedef struct __attribute__((__packed__)) bmp_header { /* header */ char const signature[2]; uint32_t file_size; uint32_t const :32; // reserved uint32_t const img_offset; /* infos */ bmp_header_infos_t infos; /* color map */ bmp_color_t colormap[bmp_colormap_size]; } bmp_header_t; typedef struct bmp_file_datas { size_t width; size_t height; /* bit map */ uint8_t *bitmap; } bmp_file_datas_t; //////////////////////////////////////////////////////////////////////////////// // functions /* give header right magic values */ bmp_header_t * bmp_get_header(void) { static bmp_header_t _header = { {'b', 'm'}, 0u, sizeof(_header), { // struct info sizeof(_header.infos), 0u, 0u, // width, height 1u, // planes 8u, // bpp 0u, // no compression 0u, // img size 0u, 0u, // resolution bmp_colormap_size, bmp_colormap_size, // important colors }, {{0u}} }; bmp_header_t *header = malloc(sizeof(_header)); size_t i, color; assert(header != null); memcpy(header, &_header, sizeof(*header)); // setting scale of greys (i = 0 ; < bmp_colormap_size ; ++i) { color = (i * 255) / bmp_colormap_size; header->colormap[i] = (bmp_color_t){color, color, color}; } return header; } /* take file content , store in buffer */ char * get_file_content(char const *filename) { file *file_handler = fopen(filename, "r"); size_t file_len; char *buff; bmp_assert(file_handler != null, strerror(errno)); fseek(file_handler, 0, seek_end); file_len = ftell(file_handler); fseek(file_handler, 0, seek_set); buff = malloc(file_len + 1); assert(buff != null); fread(buff, file_len, 1, file_handler); buff[file_len] = '\0'; fclose(file_handler); return buff; } /* greatest multiple of 4 >= size */ static inline size_t multiple_of_four(size_t size) { while (size % 4) ++size; return size; } /* informations buffer: size of line, number of lines */ void get_file_infos(char *buff, bmp_header_t *header, bmp_file_datas_t *datas) { /* width & height */ header->infos.width = strchr(buff, '\n') - buff; header->infos.height = strlen(buff) / (header->infos.width + 1); // + 1 terminating '\n' datas->width = multiple_of_four(header->infos.width); datas->height = header->infos.height; printf("file size: %u, %u\n", header->infos.width, header->infos.height); /* image size & bitmap allocation */ header->infos.img_size = datas->width * datas->height; datas->bitmap = malloc(header->infos.img_size * sizeof(*datas->bitmap)); assert(datas->bitmap != null); header->file_size = header->img_offset + header->infos.img_size; } /* take informations buffer , store them in bitmap */ void write_bitmap(char *buff, bmp_file_datas_t *datas) { size_t ibuff, iline = 0, ibitmap = 0; (ibuff = 0 ; buff[ibuff] ; ++ibuff) { if (isdigit(buff[ibuff])) { datas->bitmap[ibitmap] = bmp_colormap_size - 1 - (buff[ibuff] - '0'); ++ibitmap; } else if (buff[ibuff] == '\n') { ++iline; ibitmap = iline * datas->width; } } } /* write datas in file: header , bitmap */ void write_in_file(bmp_header_t *header, bmp_file_datas_t *datas, char const *filename) { file *file_handler = fopen(filename, "w"); bmp_assert(file_handler != null, strerror(errno)); fwrite(header, sizeof(*header), 1, file_handler); fwrite(datas->bitmap, header->infos.img_size, 1, file_handler); fclose(file_handler); } int main(int argc, char **argv) { char *buff; bmp_header_t *header; bmp_file_datas_t datas; if (argc != 3) { fprintf(stderr, "usage: %s <input filename> <output filename>\n", argv[0]); return exit_failure; } buff = get_file_content(argv[1]); header = bmp_get_header(); get_file_infos(buff, header, &datas); write_bitmap(buff, &datas); write_in_file(header, &datas, argv[2]); free(buff), free(header), free(datas.bitmap); return exit_success; } 
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