C++获取jpg和png图像的宽和高

#include "stdafx.h" #define MAKEUS(a, b) ((unsigned short) ( ((unsigned short)(a))<<8 | ((unsigned short)(b)) )) #define MAKEUI(a,b,c,d) ((unsigned int) ( ((unsigned int)(a)) << 24 | ((unsigned int)(b)) << 16 | ((unsigned int)(c)) << 8 | ((unsigned int)(d)) )) #define M_DATA 0x00 #define M_SOF0 0xc0 #define M_DHT 0xc4 #define M_SOI 0xd8 #define M_EOI 0xd9 #define M_SOS 0xda #define M_DQT 0xdb #define M_DNL 0xdc #define M_DRI 0xdd #define M_APP0 0xe0 #define M_APPF 0xef #define M_COM 0xfe #include <stdlib.h> #include <string.h> int GetPNGWidthHeight(const char* path, unsigned int* punWidth, unsigned int* punHeight) { int Finished = 0; unsigned char uc[4]; FILE *pfRead; *punWidth = 0; *punHeight = 0; if (fopen_s(&pfRead, path, "rb") != 0) { printf("[GetPNGWidthHeight]:can't open file:%s\n", path); return -1; } for (int i = 0; i < 4; i++) fread(&uc[i], sizeof(unsigned char), 1, pfRead); if (MAKEUI(uc[0], uc[1], uc[2], uc[3])!= 0x89504e47) printf("[GetPNGWidthHeight]:png format error\n", path); for (int i = 0; i < 4; i++) fread(&uc[i], sizeof(unsigned char), 1, pfRead); if (MAKEUI(uc[0], uc[1], uc[2], uc[3]) != 0x0d0a1a0a) printf("[GetPNGWidthHeight]:png format error\n", path); fseek(pfRead, 16, SEEK_SET); for (int i = 0; i < 4;i++) fread(&uc[i], sizeof(unsigned char), 1, pfRead); *punWidth = MAKEUI(uc[0], uc[1], uc[2], uc[3]); for (int i = 0; i < 4;i++) fread(&uc[i], sizeof(unsigned char), 1, pfRead); *punHeight = MAKEUI(uc[0], uc[1], uc[2], uc[3]); } int GetJPEGWidthHeight(const char* path, unsigned int *punWidth, unsigned int *punHeight) { int Finished = 0; unsigned char id, ucHigh, ucLow; FILE *pfRead; *punWidth = 0; *punHeight = 0; if (fopen_s(&pfRead,path, "rb")!=0) { printf("[GetJPEGWidthHeight]:can't open file:%s\n", path); return -1; } while (!Finished) { if (!fread(&id, sizeof(char), 1, pfRead) || id != 0xff || !fread(&id, sizeof(char), 1, pfRead)) { Finished = -2; break; } if (id >= M_APP0 && id <= M_APPF) { fread(&ucHigh, sizeof(char), 1, pfRead); fread(&ucLow, sizeof(char), 1, pfRead); fseek(pfRead, (long)(MAKEUS(ucHigh,ucLow) - 2), SEEK_CUR); continue; } switch (id) { case M_SOI: break; case M_COM: case M_DQT: case M_DHT: case M_DNL: case M_DRI: fread(&ucHigh, sizeof(char), 1, pfRead); fread(&ucLow, sizeof(char), 1, pfRead); fseek(pfRead, (long)(MAKEUS(ucHigh,ucLow) - 2), SEEK_CUR); break; case M_SOF0: fseek(pfRead, 3L, SEEK_CUR); fread(&ucHigh, sizeof(char), 1, pfRead); fread(&ucLow, sizeof(char), 1, pfRead); *punHeight = (unsigned int)MAKEUS(ucHigh,ucLow); fread(&ucHigh, sizeof(char), 1, pfRead); fread(&ucLow, sizeof(char), 1, pfRead); *punWidth = (unsigned int)MAKEUS(ucHigh,ucLow); return 0; case M_SOS: case M_EOI: case M_DATA: Finished = -1; break; default: fread(&ucHigh, sizeof(char), 1, pfRead); fread(&ucLow, sizeof(char), 1, pfRead); printf("[GetJPEGWidthHeight]:unknown id: 0x%x ; length=%hd\n", id, MAKEUS(ucHigh, ucLow)); if (fseek(pfRead, (long)(MAKEUS(ucHigh, ucLow) - 2), SEEK_CUR) != 0) Finished = -2; break; } } if (Finished == -1) printf("[GetJPEGWidthHeight]:can't find SOF0!\n"); else if (Finished == -2) printf("[GetJPEGWidthHeight]:jpeg format error!\n"); return -1; } void GetPicWidthHeight(const char* path, unsigned int *punWidth, unsigned int *punHeight) { int len = strlen(path); if (len<=4) printf("[GetPicWidthHeight]:picture name is too short\n"); if (!strncmp(path + len - 3, "jpg", 3)) GetJPEGWidthHeight(path, punWidth, punHeight); else if (!strncmp(path + len - 3, "png", 3)) GetPNGWidthHeight(path, punWidth, punHeight); else printf("[GetPicWidthHeight]:only support jpg and png\n"); } int main(int argc, char *argv[]) { unsigned int unWidth=0, unHeight=0; GetPicWidthHeight("2.jpg", &unWidth, &unHeight); printf("width is %u\n", unWidth); printf("height is %u\n", unHeight); system("pause"); return 0; }