C/C++实现bmp文件读写

  • 之前知道点bmp图的格式,然后对8位操作过,然后今天弄了一下24位真彩色的。
  • C++读取、旋转和保存bmp图像文件编程实现
  • 主要是理解bmp文件的格式8/24位的区别
  • 8位图有调色板,24位在文件头和信息头之后就是图像数据区,但是保存24位图的时候,直接在文件头和信息头之后写图像数据,会有图像错位,查看bfOffBits=138 不等于54!

BMP文件格式详解(BMP file format)

  • 实验输入图片C/C++实现bmp文件读写

实验一


#include <stdio.h>  
#include <stdlib.h>  

typedef struct
{
	//unsigned short    bfType;  
	unsigned long    bfSize;
	unsigned short    bfReserved1;
	unsigned short    bfReserved2;
	unsigned long    bfOffBits;
} ClBitMapFileHeader;

typedef struct
{
	unsigned long  biSize;
	long   biWidth;
	long   biHeight;
	unsigned short   biPlanes;
	unsigned short   biBitCount;
	unsigned long  biCompression;
	unsigned long  biSizeImage;
	long   biXPelsPerMeter;
	long   biYPelsPerMeter;
	unsigned long   biClrUsed;
	unsigned long   biClrImportant;
} ClBitMapInfoHeader;

typedef struct
{
	unsigned char rgbBlue; //该颜色的蓝色分量  
	unsigned char rgbGreen; //该颜色的绿色分量  
	unsigned char rgbRed; //该颜色的红色分量  
	unsigned char rgbReserved; //保留值  
} ClRgbQuad;

typedef struct
{
	int width;
	int height;
	int channels;
	unsigned char* imageData;
}ClImage;

ClImage* clLoadImage(char* path);
bool clSaveImage(char* path, ClImage* bmpImg);


ClImage* clLoadImage(char* path)
{
	ClImage* bmpImg;
	FILE* pFile;
	unsigned short fileType;
	ClBitMapFileHeader bmpFileHeader;
	ClBitMapInfoHeader bmpInfoHeader;
	int channels = 1;
	int width = 0;
	int height = 0;
	int step = 0;
	int offset = 0;
	unsigned char pixVal;
	ClRgbQuad* quad;
	int i, j, k;

	bmpImg = (ClImage*)malloc(sizeof(ClImage));
	pFile = fopen(path, "rb");
	if (!pFile)
	{
		free(bmpImg);
		return NULL;
	}

	fread(&fileType, sizeof(unsigned short), 1, pFile); 
	if (fileType == 0x4D42) //string "BM"
	{
		//printf("bmp file! 
");  

		fread(&bmpFileHeader, sizeof(ClBitMapFileHeader), 1, pFile);
		/*printf("\\\\\\\\\\\\\\\\\\\\\\\n");
		printf("bmp文件头信息:
");
		printf("文件大小:%d 
", bmpFileHeader.bfSize);
		printf("保留字:%d 
", bmpFileHeader.bfReserved1);
		printf("保留字:%d 
", bmpFileHeader.bfReserved2);
		printf("位图数据偏移字节数:%d 
", bmpFileHeader.bfOffBits);*/

		fread(&bmpInfoHeader, sizeof(ClBitMapInfoHeader), 1, pFile);
		/*printf("\\\\\\\\\\\\\\\\\\\\\\\n");
		printf("bmp文件信息头
");
		printf("结构体长度:%d 
", bmpInfoHeader.biSize);
		printf("位图宽度:%d 
", bmpInfoHeader.biWidth);
		printf("位图高度:%d 
", bmpInfoHeader.biHeight);
		printf("位图平面数:%d 
", bmpInfoHeader.biPlanes);
		printf("颜色位数:%d 
", bmpInfoHeader.biBitCount);
		printf("压缩方式:%d 
", bmpInfoHeader.biCompression);
		printf("实际位图数据占用的字节数:%d 
", bmpInfoHeader.biSizeImage);
		printf("X方向分辨率:%d 
", bmpInfoHeader.biXPelsPerMeter);
		printf("Y方向分辨率:%d 
", bmpInfoHeader.biYPelsPerMeter);
		printf("使用的颜色数:%d 
", bmpInfoHeader.biClrUsed);
		printf("重要颜色数:%d 
", bmpInfoHeader.biClrImportant);
		printf("\\\\\\\\\\\\\\\\\\\\\\\\n");*/

		if (bmpInfoHeader.biBitCount == 8)
		{
			//printf("该文件有调色板,即该位图为非真彩色

");  
			channels = 1;
			width = bmpInfoHeader.biWidth;
			height = bmpInfoHeader.biHeight;
			offset = (channels*width) % 4;
			if (offset != 0)
			{
				offset = 4 - offset;
			}
			//bmpImg->mat = kzCreateMat(height, width, 1, 0);  
			bmpImg->width = width;
			bmpImg->height = height;
			bmpImg->channels = 1;
			bmpImg->imageData = (unsigned char*)malloc(sizeof(unsigned char)*width*height);
			step = channels*width;

			quad = (ClRgbQuad*)malloc(sizeof(ClRgbQuad) * 256);
			fread(quad, sizeof(ClRgbQuad), 256, pFile);
			free(quad);

			for (i = 0; i<height; i++)
			{
				for (j = 0; j<width; j++)
				{
					fread(&pixVal, sizeof(unsigned char), 1, pFile);
					bmpImg->imageData[(height - 1 - i)*step + j] = pixVal;   //每次一个像素处理
				}
				if (offset != 0)
				{
					for (j = 0; j<offset; j++)
					{
						fread(&pixVal, sizeof(unsigned char), 1, pFile);
					}
				}
			}
		}
		else if (bmpInfoHeader.biBitCount == 24)
		{
			//printf("该位图为位真彩色

");  
			channels = 3;
			width = bmpInfoHeader.biWidth;
			height = bmpInfoHeader.biHeight;

			bmpImg->width = width;
			bmpImg->height = height;
			bmpImg->channels = 3;
			bmpImg->imageData = (unsigned char*)malloc(sizeof(unsigned char)*width * 3 * height);
			step = channels*width;

			offset = (channels*width) % 4;
			if (offset != 0)
			{
				offset = 4 - offset;
			}

			fseek(pFile, bmpFileHeader.bfOffBits - sizeof(bmpInfoHeader) - sizeof(bmpFileHeader), SEEK_CUR);  //138-54?感觉应该没有138才对啊

			for (i = 0; i<height; i++)
			{
				for (j = 0; j<width; j++)
				{
					for (k = 0; k<3; k++)
					{
						fread(&pixVal, sizeof(unsigned char), 1, pFile);
						bmpImg->imageData[(height - 1 - i)*step + j * 3 + k] = pixVal;  //
					}
					//kzSetMat(bmpImg->mat, height-1-i, j, kzScalar(pixVal[0], pixVal[1], pixVal[2]));  
				}
				if (offset != 0)
				{
					for (j = 0; j<offset; j++)
					{
						fread(&pixVal, sizeof(unsigned char), 1, pFile);
					}
				}
			}
		}
	}

	return bmpImg;
}

bool clSaveImage(char* path, ClImage* bmpImg)
{
	FILE *pFile;
	unsigned short fileType;
	ClBitMapFileHeader bmpFileHeader;
	ClBitMapInfoHeader bmpInfoHeader;
	int step;
	int offset;
	unsigned char pixVal = ' ';
	int i, j;
	ClRgbQuad* quad;

	pFile = fopen(path, "wb");
	if (!pFile)
	{
		return false;
	}

	fileType = 0x4D42;
	fwrite(&fileType, sizeof(unsigned short), 1, pFile);

	if (bmpImg->channels == 3)//24位,通道,彩图  
	{
		step = bmpImg->channels*bmpImg->width;
		offset = step % 4;
		if (offset != 4)
		{
			step += 4 - offset;
		}

		bmpFileHeader.bfSize = bmpImg->height*step + 54;
		bmpFileHeader.bfReserved1 = 0;
		bmpFileHeader.bfReserved2 = 0;
		bmpFileHeader.bfOffBits = 54;
		fwrite(&bmpFileHeader, sizeof(ClBitMapFileHeader), 1, pFile);

		bmpInfoHeader.biSize = 40;
		bmpInfoHeader.biWidth = bmpImg->width;
		bmpInfoHeader.biHeight = bmpImg->height;
		bmpInfoHeader.biPlanes = 1;
		bmpInfoHeader.biBitCount = 24;
		bmpInfoHeader.biCompression = 0;
		bmpInfoHeader.biSizeImage = bmpImg->height*step;
		bmpInfoHeader.biXPelsPerMeter = 0;
		bmpInfoHeader.biYPelsPerMeter = 0;
		bmpInfoHeader.biClrUsed = 0;
		bmpInfoHeader.biClrImportant = 0;
		fwrite(&bmpInfoHeader, sizeof(ClBitMapInfoHeader), 1, pFile);

		for (i = bmpImg->height - 1; i>-1; i--)
		{
			for (j = 0; j<bmpImg->width; j++)
			{
				pixVal = bmpImg->imageData[i*bmpImg->width * 3 + j * 3];
				fwrite(&pixVal, sizeof(unsigned char), 1, pFile);
				pixVal = bmpImg->imageData[i*bmpImg->width * 3 + j * 3 + 1];
				fwrite(&pixVal, sizeof(unsigned char), 1, pFile);
				pixVal = bmpImg->imageData[i*bmpImg->width * 3 + j * 3 + 2];
				fwrite(&pixVal, sizeof(unsigned char), 1, pFile);
			}
			if (offset != 0)
			{
				for (j = 0; j<offset; j++)
				{
					pixVal = 0;
					fwrite(&pixVal, sizeof(unsigned char), 1, pFile);
				}
			}
		}
	}
	else if (bmpImg->channels == 1)//8位,单通道,灰度图  
	{
		step = bmpImg->width;
		offset = step % 4;
		if (offset != 4)
		{
			step += 4 - offset;
		}

		bmpFileHeader.bfSize = 54 + 256 * 4 + bmpImg->width;
		bmpFileHeader.bfReserved1 = 0;
		bmpFileHeader.bfReserved2 = 0;
		bmpFileHeader.bfOffBits = 54 + 256 * 4;
		fwrite(&bmpFileHeader, sizeof(ClBitMapFileHeader), 1, pFile);

		bmpInfoHeader.biSize = 40;
		bmpInfoHeader.biWidth = bmpImg->width;
		bmpInfoHeader.biHeight = bmpImg->height;
		bmpInfoHeader.biPlanes = 1;
		bmpInfoHeader.biBitCount = 8;
		bmpInfoHeader.biCompression = 0;
		bmpInfoHeader.biSizeImage = bmpImg->height*step;
		bmpInfoHeader.biXPelsPerMeter = 0;
		bmpInfoHeader.biYPelsPerMeter = 0;
		bmpInfoHeader.biClrUsed = 256;
		bmpInfoHeader.biClrImportant = 256;
		fwrite(&bmpInfoHeader, sizeof(ClBitMapInfoHeader), 1, pFile);

		quad = (ClRgbQuad*)malloc(sizeof(ClRgbQuad) * 256);
		for (i = 0; i<256; i++)
		{
			quad[i].rgbBlue = i;
			quad[i].rgbGreen = i;
			quad[i].rgbRed = i;
			quad[i].rgbReserved = 0;
		}
		fwrite(quad, sizeof(ClRgbQuad), 256, pFile);
		free(quad);

		for (i = bmpImg->height - 1; i>-1; i--)
		{
			for (j = 0; j<bmpImg->width; j++)
			{
				pixVal = bmpImg->imageData[i*bmpImg->width + j];
				fwrite(&pixVal, sizeof(unsigned char), 1, pFile);
			}
			if (offset != 0)
			{
				for (j = 0; j<offset; j++)
				{
					pixVal = 0;
					fwrite(&pixVal, sizeof(unsigned char), 1, pFile);
				}
			}
		}
	}
	fclose(pFile);

	return true;
}
 

int main(int argc, char* argv[])
{
	ClImage* img = clLoadImage("F:\RANJIEWEN\CLQ_C_code\HOG_SVM_master\000001.bmp");
	bool flag = clSaveImage("E:/result.bmp", img);
	if (flag)
	{
		printf("save ok... 
");
	}

	while (1);
	return 0;
}
  • 在存24w位图的时候没有加fseek(pFile, bmpFileHeader.bfOffBits - sizeof(bmpInfoHeader) - sizeof(bmpFileHeader), SEEK_CUR); //138-54?感觉应该没有138才对啊存图不对,有错位
    C/C++实现bmp文件读写

实验二


#include<iostream>
#include <stdlib.h>
#include <windows.h>
#include <fstream>
using namespace std;


//---------------------------------------------------------------------------------------
//以下该模块是完成BMP图像(彩色图像是24bit RGB各8bit)的像素获取,并存在文件名为xiang_su_zhi.txt中
unsigned char *pBmpBuf;//读入图像数据的指针

int bmpWidth;//图像的宽
int bmpHeight;//图像的高
RGBQUAD *pColorTable;//颜色表指针

int biBitCount;//图像类型,每像素位数

//-------------------------------------------------------------------------------------------
//读图像的位图数据、宽、高、颜色表及每像素位数等数据进内存,存放在相应的全局变量中
bool readBmp(char *bmpName)
{
	FILE *fp = fopen(bmpName, "rb");//二进制读方式打开指定的图像文件

	if (fp == 0)
		return 0;

	//跳过位图文件头结构BITMAPFILEHEADER

	fseek(fp, sizeof(BITMAPFILEHEADER), 0);

	//定义位图信息头结构变量,读取位图信息头进内存,存放在变量head中

	BITMAPINFOHEADER head;

	fread(&head, sizeof(BITMAPINFOHEADER), 1, fp); //获取图像宽、高、每像素所占位数等信息

	bmpWidth = head.biWidth;

	bmpHeight = head.biHeight;

	biBitCount = head.biBitCount;//定义变量,计算图像每行像素所占的字节数(必须是4的倍数)

	int lineByte = (bmpWidth * biBitCount / 8 + 3) / 4 * 4;//灰度图像有颜色表,且颜色表表项为256

	if (biBitCount == 8)
	{

		//申请颜色表所需要的空间,读颜色表进内存

		pColorTable = new RGBQUAD[256];

		fread(pColorTable, sizeof(RGBQUAD), 256, fp);

	}

	//申请位图数据所需要的空间,读位图数据进内存

	pBmpBuf = new unsigned char[lineByte * bmpHeight];

	fread(pBmpBuf, 1, lineByte * bmpHeight, fp);

	fclose(fp);//关闭文件

	return 1;//读取文件成功
}

//-----------------------------------------------------------------------------------------
//给定一个图像位图数据、宽、高、颜色表指针及每像素所占的位数等信息,将其写到指定文件中
bool saveBmp(char *bmpName, unsigned char *imgBuf, int width, int height, int biBitCount, RGBQUAD *pColorTable)
{

	//如果位图数据指针为0,则没有数据传入,函数返回

	if (!imgBuf)
		return 0;

	//颜色表大小,以字节为单位,灰度图像颜色表为1024字节,彩色图像颜色表大小为0

	int colorTablesize = 0;

	if (biBitCount == 8)
		colorTablesize = 1024;

	//待存储图像数据每行字节数为4的倍数

	int lineByte = (width * biBitCount / 8 + 3) / 4 * 4;

	//以二进制写的方式打开文件

	FILE *fp = fopen(bmpName, "wb");

	if (fp == 0)
		return 0;

	//申请位图文件头结构变量,填写文件头信息

	BITMAPFILEHEADER fileHead;

	fileHead.bfType = 0x4D42;//bmp类型

	//bfSize是图像文件4个组成部分之和

	fileHead.bfSize = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER) + colorTablesize + lineByte*height;

	fileHead.bfReserved1 = 0;

	fileHead.bfReserved2 = 0;

	//bfOffBits是图像文件前3个部分所需空间之和

	fileHead.bfOffBits = 54 + colorTablesize;

	//写文件头进文件

	fwrite(&fileHead, sizeof(BITMAPFILEHEADER), 1, fp);

	//申请位图信息头结构变量,填写信息头信息

	BITMAPINFOHEADER head;

	head.biBitCount = biBitCount;

	head.biClrImportant = 0;

	head.biClrUsed = 0;

	head.biCompression = 0;

	head.biHeight = height;

	head.biPlanes = 1;

	head.biSize = 40;

	head.biSizeImage = lineByte*height;

	head.biWidth = width;

	head.biXPelsPerMeter = 0;

	head.biYPelsPerMeter = 0;

	//写位图信息头进内存

	fwrite(&head, sizeof(BITMAPINFOHEADER), 1, fp);

	//如果灰度图像,有颜色表,写入文件 

	if (biBitCount == 8)
		fwrite(pColorTable, sizeof(RGBQUAD), 256, fp);

	//写位图数据进文件

	fwrite(imgBuf, height*lineByte, 1, fp);

	//关闭文件

	fclose(fp);

	return 1;

}

//----------------------------------------------------------------------------------------
//以下为像素的读取函数
void doIt()
{

	//读入指定BMP文件进内存

	char readPath[] = "F:\RANJIEWEN\CLQ_C_code\HOG_SVM_master\000001.bmp";

	readBmp(readPath);

	//输出图像的信息

	cout << "width=" << bmpWidth << " height=" << bmpHeight << " biBitCount=" << biBitCount << endl;

	//循环变量,图像的坐标

	//每行字节数

	int lineByte = (bmpWidth*biBitCount / 8 + 3) / 4 * 4;

	//循环变量,针对彩色图像,遍历每像素的三个分量

	int m = 0, n = 0, count_xiang_su = 0;

	//将图像左下角1/4部分置成黑色

	ofstream outfile("图像像素.txt", ios::in | ios::trunc);

	if (biBitCount == 8) //对于灰度图像
	{
		//------------------------------------------------------------------------------------
		//以下完成图像的分割成8*8小单元,并把像素值存储到指定文本中。由于BMP图像的像素数据是从
		//左下角:由左往右,由上往下逐行扫描的
		int L1 = 0;
		int hang = 63;
		int lie = 0;
		//int L2=0;
		//int fen_ge=8;
		for (int fen_ge_hang = 0; fen_ge_hang<8; fen_ge_hang++)//64*64矩阵行循环
		{
			for (int fen_ge_lie = 0; fen_ge_lie<8; fen_ge_lie++)//64*64列矩阵循环
			{
				//--------------------------------------------
				for (L1 = hang; L1>hang - 8; L1--)//8*8矩阵行
				{
					for (int L2 = lie; L2<lie + 8; L2++)//8*8矩阵列
					{
						m = *(pBmpBuf + L1*lineByte + L2);
						outfile << m << " ";
						count_xiang_su++;
						if (count_xiang_su % 8 == 0)//每8*8矩阵读入文本文件
						{
							outfile << endl;
						}
					}
				}
				//---------------------------------------------
				hang = 63 - fen_ge_hang * 8;//64*64矩阵行变换
				lie += 8;//64*64矩阵列变换
				//该一行(64)由8个8*8矩阵的行组成
			}
			hang -= 8;//64*64矩阵的列变换
			lie = 0;//64*64juzhen
		}
	}

	//double xiang_su[2048];
	//ofstream outfile("xiang_su_zhi.txt",ios::in|ios::trunc);
	if (!outfile)
	{
		cout << "open error!" << endl;
		exit(1);
	}
	else if (biBitCount == 24)
	{//彩色图像
		for (int i = 0; i<bmpHeight; i++)
		{
			for (int j = 0; j<bmpWidth; j++)
			{
				for (int k = 0; k<3; k++)//每像素RGB三个分量分别置0才变成黑色
				{
					//*(pBmpBuf+i*lineByte+j*3+k)-=40;
					m = *(pBmpBuf + i*lineByte + j * 3 + k);
					outfile << m << " ";
					count_xiang_su++;
					if (count_xiang_su % 8 == 0)
					{
						outfile << endl;
					}
					//n++;
				}
				n++;
			}


		}
		cout << "总的像素个素为:" << n << endl;
		cout << "----------------------------------------------------" << endl;
	}

	//将图像数据存盘

	char writePath[] = "E://nvcpy.BMP";//图片处理后再存储

	saveBmp(writePath, pBmpBuf, bmpWidth, bmpHeight, biBitCount, pColorTable);

	//清除缓冲区,pBmpBuf和pColorTable是全局变量,在文件读入时申请的空间

	delete[]pBmpBuf;

	if (biBitCount == 8)
		delete[]pColorTable;
}

void main()
{
	doIt();
}
  • 没有fseek,24位图错位

实验三

  • 我自己使用的8/24分别写成函数的

#include "readbmp.h"
#include "stdio.h"
#include "string.h"
#include "malloc.h"

//typedef unsigned short WORD;
//typedef unsigned int DWORD;
//typedef int LONG;
//typedef struct tagBITMAPFILEHEADER {
//	WORD    bfType;
//	DWORD   bfSize;
//	WORD    bfReserved1;
//	WORD    bfReserved2;
//	DWORD   bfOffBits;
//} BITMAPFILEHEADER;
//typedef struct tagBITMAPINFOHEADER{
//	DWORD      biSize;
//	LONG        biWidth;
//	LONG        biHeight;
//	WORD       biPlanes;
//	WORD       biBitCount;
//	DWORD      biCompression;
//	DWORD      biSizeImage;
//	LONG        biXPelsPerMeter;
//	LONG        biYPelsPerMeter;
//	DWORD      biClrUsed;
//	DWORD      biClrImportant;
//} BITMAPINFOHEADER;


#include "windows.h"  //BITMAPFILEHEADER包含文件

myMat *loadBitmapFromFile24(const char *filePath, U8 **bits)     //24
{
	myMat *img;
	img = (myMat*)malloc(sizeof(myMat));
	if (!img) {
		fprintf(stderr, "Unable to allocate memory
");
		exit(1);
	}

	FILE *fp = fopen(filePath, "rb");
	if (fp == NULL) {
		exit(-1);
	}
	BITMAPFILEHEADER bfh;
	if (fread(&bfh, sizeof(bfh), 1, fp) != 1) {
		fclose(fp);
		exit(-1);
	}
	BITMAPINFOHEADER bih;
	if (fread(&bih, sizeof(bih), 1, fp) != 1) {
		fclose(fp);
		exit(-1);
	}
	if (bih.biBitCount != 24) {
		fclose(fp);
		printf("unsupported bitmap format.
");
		exit(-1);
	}
	int imageSize = (bih.biWidth*3 + 3) / 4 * 4 * bih.biHeight;

	img->width = bih.biWidth;
	img->height = bih.biHeight;
	img->type = myCV_8U;
	img->dims = 2;
	img->channels = 3;
	img->step = imageSize / bih.biHeight;
	img->totalsize = imageSize;
	img->data = (uchar*)malloc(img->totalsize);
	img->dataend = img->datalimit = (uchar*)img->data + img->totalsize;

	fseek(fp, bfh.bfOffBits - sizeof(bfh) - sizeof(bih), SEEK_CUR);  //138-54?感觉应该没有138才对啊

	if (fread(img->data, 1, imageSize, fp) != imageSize) {
		fclose(fp);
		exit(-1);
	}
	fclose(fp);

	U8 *buffer = (U8 *)malloc(imageSize);
	buffer = img->data;
	*bits = buffer;

	return img;
}

myMat *loadBitmapFromFile8(const char *filePath, U8 **bits)     //----8
{
	myMat *img;
	img = (myMat*)malloc(sizeof(myMat));
	if (!img) {
		fprintf(stderr, "Unable to allocate memory
");
		exit(1);
	}

	FILE *fp = fopen(filePath, "rb");
	if (fp == NULL) {
		exit(-1);
	}
	BITMAPFILEHEADER bfh;
	if (fread(&bfh, sizeof(bfh), 1, fp) != 1) {
		fclose(fp);
		exit(-1);
	}
	BITMAPINFOHEADER bih;
	if (fread(&bih, sizeof(bih), 1, fp) != 1) {
		fclose(fp);
		exit(-1);
	}
	if (bih.biBitCount != 8) {
		fclose(fp);
		printf("unsupported bitmap format.
");
		exit(-1);
	}
	int imageSize = (bih.biWidth + 3) / 4 * 4 * bih.biHeight;

	img->width = bih.biWidth;
	img->height = bih.biHeight;
	img->type = myCV_8U;
	img->dims = 2;
	img->channels = 1;
	img->step = imageSize / bih.biHeight;
	img->totalsize = imageSize ;
	img->data = (uchar*)malloc(img->totalsize);
	img->dataend = img->datalimit = (uchar*)img->data + img->totalsize;

	fseek(fp, bfh.bfOffBits - sizeof(bfh) - sizeof(bih), SEEK_CUR);

	U8 *buffer = (U8 *)malloc(imageSize );

	if (fread(img->data, 1, imageSize, fp) != imageSize) {
		fclose(fp);
		exit(-1);
	}
	
	fclose(fp);

	*bits = buffer;

	return img;
}

int CreateImage(IplImage_ *_img, int _width, int _height, U8 *_image_data)
{
	if (_img->valid)
	{
		return -1;	//这个图像结构体已经有用了
	}
	if (_width & 3)	//是否是4的整数倍
	{
		_img->width_step = (_width & (~3)) + 4;
	}
	else
	{
		_img->width_step = _width;
	}
	_img->width = _width;
	_img->height = _height;
	_img->image_data = _image_data;
	_img->valid = 1;
	return 0;
}

void ReleaseImage(IplImage_ *_img)
{
	_img->width_step = 0;
	_img->width = 0;
	_img->height = 0;
	_img->image_data = 0;
	_img->valid = 0;
}

void SaveGrayBitmap24(const char *fileName, const U8 *imageData, int width, int height)
{
	BITMAPFILEHEADER bfh;
	BITMAPINFOHEADER bih;
	DWORD palette[256];
	int i, imageSize;
	FILE *fp = fopen(fileName, "wb");
	int widthS = (width*3 + 3) / 4 * 4;
	imageSize = widthS* height;

	if (fp == NULL)
	{
		return;
	}

	memset(&bfh, 0, sizeof(bfh));
	bfh.bfType = 0x4d42;
	bfh.bfSize = imageSize + sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER);;
	bfh.bfOffBits = sizeof(BITMAPFILEHEADER)+sizeof(BITMAPINFOHEADER);
	bfh.bfReserved1 = 0;
	bfh.bfReserved2 = 0;
	fwrite(&bfh, sizeof(bfh), 1, fp);

	memset(&bih, 0, sizeof(bih));
	bih.biSize = sizeof(bih);
	bih.biWidth = width;
	bih.biHeight = height;
	bih.biPlanes = 1;
	bih.biBitCount = 24;
	bih.biCompression = 0;
	bih.biSizeImage = imageSize;
	bih.biXPelsPerMeter = 0;
	bih.biYPelsPerMeter = 0;
	bih.biClrUsed = 0;
	bih.biClrImportant = 0;
	fwrite(&bih, sizeof(bih), 1, fp);

	for (i = 0; i < height; i++)
	{
		fwrite(imageData + (height - i - 1)*widthS, 1, widthS, fp);
	}

	fclose(fp);
}

void SaveGrayBitmap8(const char *fileName, const U8 *imageData, int width, int height)  //8
{
	BITMAPFILEHEADER bfh;
	BITMAPINFOHEADER bih;
	DWORD palette[256];
	int i, imageSize;

	FILE *fp = fopen(fileName, "wb");
	int widthS = (width + 3) / 4 * 4;
	imageSize = widthS* height;

	if (fp == NULL)
	{
		return;
	}

	memset(&bfh, 0, sizeof(bfh));
	bfh.bfType = 0x4d42;
	bfh.bfSize = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER) + 256 * 4 + imageSize;
	bfh.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER) + 256 * 4;
	bfh.bfReserved1 = 0;
	bfh.bfReserved2 = 0;
	fwrite(&bfh, sizeof(bfh), 1, fp);

	memset(&bih, 0, sizeof(bih));
	bih.biSize = sizeof(bih);
	bih.biWidth = width;
	bih.biHeight = height;
	bih.biPlanes = 1;
	bih.biBitCount = 8;
	bih.biCompression = 0;
	bih.biSizeImage = imageSize;
	bih.biXPelsPerMeter = 0;
	bih.biYPelsPerMeter = 0;
	bih.biClrUsed = 0;
	bih.biClrImportant = 0;
	fwrite(&bih, sizeof(bih), 1, fp);

	for (i = 0; i < 256; i++)
	{
		palette[i] = (i << 16) | (i << 8) | i;
	}
	fwrite(palette, sizeof(palette), 1, fp);

	for (i = 0; i < height; i++)
	{
		fwrite(imageData + (height - i - 1)*widthS, 1, widthS, fp);
	}

	fclose(fp);
}

实验四

  • C++类实现
void SaveToBmpGray::save(const unsigned char* src, int height, int width, std::string path, std::string name)
{
	int imagDataSize = height*width; // imag data size

	//位图第三部分,调色板
	RGBQUAD rgbQuad[256];
	for (int i = 0; i < 256; ++i)
	{
		rgbQuad[i].rgbBlue = (BYTE)i;
		rgbQuad[i].rgbGreen = (BYTE)i;
		rgbQuad[i].rgbRed = (BYTE)i;
		rgbQuad[i].rgbReserved = i;
	}

	//位图第一部分,位图文件头
	BITMAPFILEHEADER *bfHeader{ new BITMAPFILEHEADER };
	bfHeader->bfType = (WORD)0x4d42;  // string"BM"  
	bfHeader->bfSize = (DWORD)(imagDataSize + sizeof(BITMAPFILEHEADER)+sizeof(BITMAPINFOHEADER)+sizeof(rgbQuad)); // file size
	bfHeader->bfReserved1 = 0; // reserved  
	bfHeader->bfReserved2 = 0; // reserved  
	bfHeader->bfOffBits = (DWORD)(sizeof(BITMAPFILEHEADER)+sizeof(BITMAPINFOHEADER)+sizeof(rgbQuad)); // real data 位置  

	//位图第二部分,位图信息头  
	BITMAPINFOHEADER *biHeader{ new BITMAPINFOHEADER };
	biHeader->biSize = sizeof(BITMAPINFOHEADER);
	biHeader->biWidth = width;
	biHeader->biHeight = -height;//BMP图片从最后一个点开始扫描,显示时图片是倒着的,所以用-height,这样图片就正了  
	biHeader->biPlanes = 1;//为1,不用改  
	biHeader->biBitCount = 8; // 每个像素占用的bit
	biHeader->biCompression = BI_RGB;//不压缩  
	biHeader->biSizeImage = imagDataSize;
	biHeader->biXPelsPerMeter = 0;//像素每米  
	biHeader->biYPelsPerMeter = 0;
	biHeader->biClrUsed = 0;//已用过的颜色,24位的为0  
	biHeader->biClrImportant = 0;//每个像素都重要 

	//打开文件并保存
	//文件路径
	std::string fpath;
	fpath += path;
	if (name.empty())
		fpath += "IMG_";
	else
		fpath += name + "_";
	SYSTEMTIME st;
	GetLocalTime(&st);
	char time[20];
	sprintf_s(time, sizeof(st), "%4d%2d%2d_%2d%2d%2d", st.wYear, st.wMonth, st.wDay, st.wHour, st.wMinute, st.wSecond);
	for (int i = 0; time[i]; ++i)
	{
		if (time[i] == ' ') time[i] = '0';
	}
	fpath += time;
	fpath += ".bmp";
	std::fstream file(fpath, std::ios::out | std::ios::binary);
	file.write((char*)bfHeader, sizeof(BITMAPFILEHEADER));
	file.write((char*)biHeader, sizeof(BITMAPINFOHEADER));
	file.write((char*)rgbQuad, sizeof(rgbQuad));
	file.write((char*)src, imagDataSize);
	file.close();
}

void SaveToBmp24::save(const unsigned char* src, int height, int width, std::string path, std::string name)
{
	int imagDataSize = height*width * 3; // imag data size

	//位图第一部分,位图文件头
	BITMAPFILEHEADER *bfHeader{ new BITMAPFILEHEADER };
	bfHeader->bfType = 0x4d42;  // string"BM"  
	bfHeader->bfSize = imagDataSize + sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER); // file size
	bfHeader->bfReserved1 = 0; // reserved  
	bfHeader->bfReserved2 = 0; // reserved  
	bfHeader->bfOffBits = sizeof(BITMAPFILEHEADER)+sizeof(BITMAPINFOHEADER); // real data 位置  

	//位图第二部分,位图信息头  
	BITMAPINFOHEADER *biHeader{ new BITMAPINFOHEADER };
	biHeader->biSize = sizeof(BITMAPINFOHEADER);
	biHeader->biWidth = width;
	biHeader->biHeight = height;//BMP图片从最后一个点开始扫描,显示时图片是倒着的,所以用-height,这样图片就正了  
	biHeader->biPlanes = 1;//为1,不用改  
	biHeader->biBitCount = 24; // 每个像素占用的bit
	biHeader->biCompression = BI_RGB;//不压缩  
	biHeader->biSizeImage = imagDataSize;
	biHeader->biXPelsPerMeter = 0;//像素每米  
	biHeader->biYPelsPerMeter = 0;
	biHeader->biClrUsed = 0;//已用过的颜色,24位的为0  
	biHeader->biClrImportant = 0;//每个像素都重要 

	//打开文件并保存
	//文件路径
	std::string fpath;
	fpath += path;
	if (name.empty())
		fpath += "IMG_";
	else
		fpath += name + "_";
	SYSTEMTIME st;
	GetLocalTime(&st);
	char time[20];
	sprintf_s(time, sizeof(st), "%4d%2d%2d_%2d%2d%2d", st.wYear, st.wMonth, st.wDay, st.wHour, st.wMinute, st.wSecond);
	for (int i = 0; time[i]; ++i)
	{
		if (time[i] == ' ') time[i] = '0';
	}
	fpath += time;
	fpath += ".bmp";
	std::fstream file(fpath, std::ios::out | std::ios::binary);
	file.write((char*)bfHeader, sizeof(BITMAPFILEHEADER));
	file.write((char*)biHeader, sizeof(BITMAPINFOHEADER));
	file.write((char*)src, imagDataSize);
	file.close();
}