数字图像处理实验一(位图文件信息的提取和二值化处理)

数字图像处理实验一（位图文件信息的提取和二值化处理）实验平台：MinGW（Mini Gnu for Windows），里面包含gcc for windows的编译器，将其拷贝值某目录，然后设置环境变量（这里我设为c:\MinGW,通过一个批处理命令setc.bat实现）设置完成后，即可通过gcc(g++)命令进行编译。

（附：使用VC++ 6.0 也可）相关实验文件下载地址：ftp://218.193.154.238 /课件/数字图像处理/实验步骤：拷贝MinGW文件夹至C: (路径为C:\MinGW)编辑setc.bat文件，然后运行此批处理以设置路径。

编辑hdr.h 和hdr.c文件编辑bmphdr.c文件，然后在当前文件路径下，使用DOS命令：gcc -c hdr.c //编译，生成hdr.o目标文件gcc -c bmphdr.c //编译，生成bmphdr.o目标文件gcc -o bmphdr.exe hdr.o bmphdr.o //链接，生成bmphdr.exe执行文件使用bmphdr.exe来提取某一个bmp文件的头信息,例如:bmphdr test.bmp编辑ez.c文件（用于图像的二值化处理）,然后gcc -c ez.c //编译，生成ez.o目标文件gcc -o ez.exe hdr.o ez.o //链接，生成ez.exe执行文件使用ez.exe文件来对某一个bmp文件进行二值化处理。

例如：ez test.bmp result.bmp 108 （对test.bmp文件进行二值化处理，阈值为108，处理的结果为result.bmp文件)setc.bat内容：@echo offset msdir=C:\MinGWset PATH="%msdir%\bin";"%PATH%"set INCLUDE=%msdir%\Include;%msdir%\MFC\Include;%INCLUDE%set LIB=%msdir%\Lib;%LIB%补充：如果以上批处理命令无效的话，可以：我的电脑->属性->高级->环境变量编辑变量path 增加C:\ MinGW\bin hdr.h文件内容：#ifndef __HDR_H__#define __HDR_H__struct bmphdr {char signature[2];int size;short reserved[2];int offset;int hdr_size;int width;int height;short nr_planes;short bits_per_pixel;int compress_type;int data_size;int resol_hori;int resol_vert;int nr_colors;int important_color;char info[1024];};struct bmphdr *get_header(char filename[]);#endifhdr.c文件内容:#include <stdio.h>#include <memory.h>#include "hdr.h"struct bmphdr *get_header(char filename[]){FILE *fp;struct bmphdr *hdr;fp = fopen(filename, "rb");if (!fp) {printf("File open error or such file does not exist!\n");return NULL;}hdr = (struct bmphdr *)malloc(sizeof(struct bmphdr));fread(hdr->signature, 2, 1, fp);if (hdr->signature[0] != 'B' || hdr->signature[1] != 'M') { printf("Not a bmp file!\n");return NULL;}fread(&hdr->size, 4, 1, fp);fread(hdr->reserved, 4, 1, fp);fread(&hdr->offset, 4, 1, fp);fread(&hdr->hdr_size, 4, 1, fp);fread(&hdr->width, 4, 1, fp);fread(&hdr->height, 4, 1, fp);fread(&hdr->nr_planes, 2, 1, fp);fread(&hdr->bits_per_pixel, 2, 1, fp);fread(&hdr->compress_type, 4, 1, fp);fread(&hdr->data_size, 4, 1, fp);fread(&hdr->resol_hori, 4, 1, fp);fread(&hdr->resol_vert, 4, 1, fp);fread(&hdr->nr_colors, 4, 1, fp);fread(&hdr->important_color, 4, 1, fp);if (hdr->offset > 54)fread(&hdr->info, 1024, 1, fp);fclose(fp);return hdr;bmphdr.c文件内容:#include <stdio.h>struct bmphdr {char signature[2];int size;short reserved[2];int offset;int hdr_size;int width;int height;short nr_planes;short bits_per_pixel;int compress_type;int data_size;int resol_hori;int resol_vert;int nr_colors;int important_color;} header;int main(int argc, char *argv[]){FILE *fp;if (argc != 2) {printf("Usage: %s <filename>\n", argv[0]);exit(1);}fp = fopen(argv[1], "r");if (!fp) {printf("File open error or such file does not exist!\n");exit(1);}fread(header.signature, 2, 1, fp);if (header.signature[0] != 'B' || header.signature[1] != 'M') { printf("Not a bmp file!\n");exit(1);}fread(&header.size, 4, 1, fp);fread(header.reserved, 4, 1, fp);fread(&header.offset, 4, 1, fp);fread(&header.hdr_size, 4, 1, fp);fread(&header.width, 4, 1, fp);fread(&header.height, 4, 1, fp);fread(&header.nr_planes, 2, 1, fp);fread(&header.bits_per_pixel, 2, 1, fp);fread(&press_type, 4, 1, fp);fread(&header.data_size, 4, 1, fp);fread(&header.resol_hori, 4, 1, fp);fread(&header.resol_vert, 4, 1, fp);fread(&header.nr_colors, 4, 1, fp);fread(&header.important_color, 4, 1, fp);fclose(fp);printf("signature %c%c\n", header.signature[0], header.signature[1]);printf("size %d\n", header.size);printf("offset %d\n", header.offset);printf("hdr_size %d\n", header.hdr_size);printf("width %d\n", header.width);printf("height %d\n", header.height);printf("nr_planes %d\n", header.nr_planes);printf("bits_per_pixel %d\n", header.bits_per_pixel);printf("compress_type %d\n", press_type);printf("data_size %d\n", header.data_size);printf("resol_hori %d\n", header.resol_hori);printf("resol_vert %d\n", header.resol_vert);printf("nr_colors %d\n", header.nr_colors);printf("important_color %d\n", header.important_color);printf("\n");return 0;}二值化程序ez.c 文件内容：#include <stdio.h>#include <stdlib.h>#include <memory.h>#include "hdr.h"struct bmphdr *hdr;unsigned char *bitmap, *to;char buf[2048];int main(int argc, char *argv[]){int i, j, k, nr_pixels;FILE *fp, *fpnew;unsigned g;if (argc != 4) {printf("Usage: %s <file_from> <file_to> <threshold>\n", argv[0]);exit(1);}hdr = get_header(argv[1]);if (!hdr) exit(1);fp = fopen(argv[1], "rb");if (!fp) {printf("File open error!\n");exit(1);}fseek(fp, hdr->offset, SEEK_SET);nr_pixels = hdr->width * hdr->height;bitmap = malloc(nr_pixels);fread(bitmap, nr_pixels, 1, fp);fclose(fp);k = atoi(argv[3]);to = malloc(nr_pixels);memset(to, 0, nr_pixels);for (i = 0; i < nr_pixels; i++)to[i] = bitmap[i] > (unsigned char)k ? 255 : 0;fpnew = fopen(argv[2], "wb+");if (!fpnew) {printf("File create error!\n");exit(1);}fwrite(hdr->signature, 2, 1, fpnew);fwrite(&hdr->size, 4, 1, fpnew);fwrite(hdr->reserved, 4, 1, fpnew);fwrite(&hdr->offset, 4, 1, fpnew);fwrite(&hdr->hdr_size, 4, 1, fpnew);fwrite(&hdr->width, 4, 1, fpnew);fwrite(&hdr->height, 4, 1, fpnew);fwrite(&hdr->nr_planes, 2, 1, fpnew);fwrite(&hdr->bits_per_pixel, 2, 1, fpnew);fwrite(&hdr->compress_type, 4, 1, fpnew);fwrite(&hdr->data_size, 4, 1, fpnew);fwrite(&hdr->resol_hori, 4, 1, fpnew);fwrite(&hdr->resol_vert, 4, 1, fpnew);fwrite(&hdr->nr_colors, 4, 1, fpnew);fwrite(&hdr->important_color, 4, 1, fpnew);if (hdr->offset > 54)fwrite(hdr->info, hdr->offset - 54, 1, fpnew);fwrite(to, nr_pixels, 1, fpnew);fclose(fpnew);free(hdr);free(bitmap);return 0;}。