#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>
#include <stdio.h>
#include <stdlib.h>
#include <time.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("C:\\Users\\Administrator\\Pictures\\test.jpg", &unWidth, &unHeight);

    printf("width is %u\n", unWidth);
    printf("height is %u\n", unHeight);

    system("pause");
    return 0;
}

Win10系统怎么查看图片尺寸(大小)?