bmp24位转8位

#include <stdio.h> #include <stdlib.h> #include <string.h> #include <malloc.h> #include <ctype.h> #include <process.h> #include "bmp_2.h" BITMAPFILEHEADER bmfh; BITMAPINFOHEADER bmih; BITMAPFILEHEADER bf8; BITMAPINFOHEADER bi8; BYTE *imgData; BYTE *NewImgData; void readData(); int ReadFileHeader(BITMAPFILEHEADER *); int ReadInfoHeader(BITMAPINFOHEADER *); int ReadPixelData(BYTE *); void PrintFileHeader(BITMAPFILEHEADER *); void PrintInfoHeader(BITMAPINFOHEADER *); LONG GetLineBytes(int, int); int ConVerTo8BitGray(char *); void readData() { int i, k, h; DWORD dwLineBytes; i = ReadFileHeader(&bmfh); if (i == 0) { printf("Read file header successful!\n"); } k = ReadInfoHeader(&bmih); if (k == 0) { printf("Read info header successful!\n"); } dwLineBytes = GetLineBytes(bmih.biWidth, bmih.biBitCount); imgData = (BYTE*)malloc(dwLineBytes*bmih.biHeight*sizeof(BYTE)); h = ReadPixelData(imgData); if (h == 0) { printf("Read pixel data successful!\n"); } if (i == 0 && k == 0 && h == 0) { printf("Read datas successful!\n"); } } int ReadFileHeader(BITMAPFILEHEADER *bmfh) //读文件头文件 { FILE *dataFile; dataFile = fopen("D:\\a0.bmp", "r"); if (fread(&bmfh->bfType, sizeof(WORD), 1, dataFile) != 1) //读入文件头文件中的文件类型元素 { printf("Can not read bfType in the file header.\n"); fclose(dataFile); return -1; } if (fread(&bmfh->bfSize, sizeof(DWORD), 1, dataFile) != 1) //读入文件大小元素 { printf("Can not read bfSize in the file header.\n"); fclose(dataFile); return -1; } if (fread(&bmfh->bfReserved1, sizeof(WORD), 1, dataFile) != 1) //必须设置为0 { printf("Can not read bfReserved1 in the file header.\n"); fclose(dataFile); return -1; } if (fread(&bmfh->bfReserved2, sizeof(WORD), 1, dataFile) != 1) //必须设置为0 { printf("Can not read bfReserved2 in the file header.\n"); fclose(dataFile); return -1; } if (fread(&bmfh->bfOffBits, sizeof(DWORD), 1, dataFile) != 1) //从文件头开始到实际图像数据之间的字节偏移量 { printf("Can not read bfOffBits in the file header.\n"); fclose(dataFile); return -1; } fclose(dataFile); return 0; } int ReadInfoHeader(BITMAPINFOHEADER *bmih) //读信息头文件 { FILE *dataFile; dataFile = fopen("D:\\a0.bmp", "r"); fseek(dataFile, 14, SEEK_SET); //文件指针跳过文件头 if (fread(&bmih->biSize, sizeof(DWORD), 1, dataFile) != 1) //读入信息头文件结构所需要的字节数 { printf("Can not read biSize in the info header.\n"); fclose(dataFile); return -1; } if (fread(&bmih->biWidth, sizeof(LONG), 1, dataFile) != 1) //读入图像宽度 { printf("Can not read biWidth in the info header.\n"); fclose(dataFile); return -1; } if (fread(&bmih->biHeight, sizeof(LONG), 1, dataFile) != 1) //读入图像高度 { printf("Can not read biHeight in the info header.\n"); fclose(dataFile); return -1; } if (fread(&bmih->biPlanes, sizeof(WORD), 1, dataFile) != 1) //读入位图平面数，总是设置为1 { printf("Can not read biPlanes in the info header.\n"); fclose(dataFile); return -1; } if (fread(&bmih->biBitCount, sizeof(WORD), 1, dataFile) != 1) //读入比特数，即位图的位数 { printf("Can not read biBitCount in the info header.\n"); fclose(dataFile); return -1; } if (fread(&bmih->biCompression, sizeof(DWORD), 1, dataFile) != 1) //说明图像数据压缩类型 { printf("Can not read biCompression in the info header.\n"); fclose(dataFile); return -1; } if (fread(&bmih->biSizeImage, sizeof(DWORD), 1, dataFile) != 1) //读入图像大小 { printf("Can not read biSizeImage in the info header.\n"); fclose(dataFile); return -1; } if (fread(&bmih->biXPelsPerMeter, sizeof(LONG), 1, dataFile) != 1) //说明水平分辨率 { printf("Can not read biXPelsPerMeter in the info header.\n"); fclose(dataFile); return -1; } if (fread(&bmih->biYPelsPerMeter, sizeof(LONG), 1, dataFile) != 1) //说明垂直分辨率 { printf("Can not read biYPelsPerMeter in the info header.\n"); fclose(dataFile); return -1; } if (fread(&bmih->biClrUsed, sizeof(DWORD), 1, dataFile) != 1) //说明位图实际使用的彩色表中颜色索引数 { printf("Can not read biClrUsed in the info header.\n"); fclose(dataFile); return -1; } if (fread(&bmih->biClrImportant, sizeof(DWORD), 1, dataFile) != 1) //说明对图像显示有重要影响的颜色索引数 { printf("Can not read biClrImportant in the info header.\n"); fclose(dataFile); return -1; } fclose(dataFile); return 0; } int ReadPixelData(BYTE *imgData) //读取像素数据 { BYTE *data; FILE *dataFile; DWORD dwLineBytes; dwLineBytes = GetLineBytes(bmih.biWidth, bmih.biBitCount); data = (BYTE *)malloc(dwLineBytes*bmih.biHeight*sizeof(BYTE)); dataFile = fopen("D:\\a0.bmp", "rb"); if (bmih.biBitCount == 8) { fseek(dataFile, bmfh.bfOffBits, SEEK_SET); } else if (bmih.biBitCount == 24) { fseek(dataFile, bmfh.bfOffBits, SEEK_SET); } else { printf("Only Support: 8 or 24 bits.\n"); free(data); fclose(dataFile); return -1; } if (fread(data, dwLineBytes*bmih.biHeight*sizeof(BYTE), 1, dataFile) != 1) { printf("Can not read the pixel data.\n"); free(data); fclose(dataFile); return -1; } memcpy(imgData, data, dwLineBytes*bmih.biHeight*sizeof(BYTE)); free(data); fclose(dataFile); return 0; } void PrintFileHeader(BITMAPFILEHEADER *ibmfh) //打印文件头信息 { printf("The contents in the file header of the BMP file:\n"); printf("bfOffBits: %ld\n", ibmfh->bfOffBits); printf("bfReserved1: %ld\n", ibmfh->bfReserved1); printf("bfReserved2: %ld\n", ibmfh->bfReserved2); printf("bfSize: %ld\n", ibmfh->bfSize); printf("bfType: %ld\n", ibmfh->bfType); } void PrintInfoHeader(BITMAPINFOHEADER *ibmih) //打印信息头信息 { printf("The content in the info header of the BMP file:\n"); printf("biBitCount: %ld\n", ibmih->biBitCount); printf("biClrImportant: %ld\n", ibmih->biClrImportant); printf("biClrUsed: %ld\n", ibmih->biClrUsed); printf("biCompression: %ld\n", ibmih->biCompression); printf("biHeight: %ld\n", ibmih->biHeight); printf("biPlanes: %ld\n", ibmih->biPlanes); printf("biSize: %ld\n", ibmih->biSize); printf("biSizeImage: %ld\n", ibmih->biSizeImage); printf("biWidth: %ld\n", ibmih->biWidth); printf("biXPelsPerMeter: %ld\n", ibmih->biXPelsPerMeter); printf("biYPelsPerMeter: %ld\n", ibmih->biYPelsPerMeter); } LONG GetLineBytes(int imgWidth, int bitCount) //计算每行像素所占的字节数 { return (imgWidth*bitCount + 31) / 32 * 4; } int ConVerTo8BitGray(char *filepath) //24位图转换8位图 { int i, j, k; FILE *dataFile; DWORD dwLineBytes8; DWORD dwLineBytes24; RGBQUAD pal[256]; dwLineBytes24 = GetLineBytes(bmih.biWidth, 24); dwLineBytes8 = GetLineBytes(bmih.biWidth, 8); NewImgData = (BYTE *)malloc(dwLineBytes8*bmih.biHeight*sizeof(BYTE)); for (i = 0; i<bmih.biHeight; i++) { k = 0; for (j = 0; j<dwLineBytes24; j = j + 3) { NewImgData[k + i*dwLineBytes8] = 0.114*imgData[i*dwLineBytes24 + j] + 0.587*imgData[i*dwLineBytes24 + j + 1] + 0.299*imgData[i*dwLineBytes24 + j + 2]; k++; } } for (i = 0; i<256; i++) { pal[i].rgbBlue = i; pal[i].rgbGreen = i; pal[i].rgbRed = i; pal[i].rgbReserved = 0; } bf8.bfOffBits = bmfh.bfOffBits + 256 * sizeof(RGBQUAD); bf8.bfReserved1 = 0; bf8.bfReserved2 = 0; bf8.bfSize = sizeof(BITMAPFILEHEADER) + dwLineBytes8*bmih.biHeight; bf8.bfType = 19778; bi8.biBitCount = 8; bi8.biClrImportant = 0; bi8.biClrUsed = 0; bi8.biCompression = 0; bi8.biHeight = bmih.biHeight; bi8.biPlanes = 1; bi8.biSize = 40; bi8.biSizeImage = dwLineBytes8*bmih.biHeight; bi8.biWidth = bmih.biWidth; bi8.biXPelsPerMeter = 0; bi8.biYPelsPerMeter = 0; dataFile = fopen(filepath, "wb"); //以写的方式打开文件 if (!dataF