为什么我的jpeg没有恢复，在recoverc.c？

Question

为什么恢复时我的JPEG无法恢复。 C？ 不确定我做错了什么，如果你看到任何关闭，请告诉我。 我嵌入了评论以避免混淆。

typedef uint8_t BYTE;

int main(void)
{
    FILE* fimg = fopen("card.raw", "r");

    if (fimg == NULL)
    {
        fclose(fimg);
        fprintf(stderr, "Image does not exist in the cardfile.\n");
        return 1;
    }

    // counter to keep track of files found
    int counter = 0; 

    // a buffer of 512 bytes
    BYTE buffer[512];

    BYTE check[4];
    FILE* temp = NULL;

    fread(buffer, 512, 1, fimg);

    // starting bytes for the jpeg files.
    BYTE chkjpg0[4] = {0xff, 0xd8, 0xff, 0xe0};
    BYTE chkjpg1[4] = {0xff, 0xd8, 0xff, 0xe1};
    char fname[10]; 

    while (fread(buffer, 512, 1, fimg) > 0)
    {
        // check first couple of sequence of the jpg
        for(int i = 0; i < 4; i++)
        {
            check[i] = buffer[i];

        }

        if (chkjpg0 == 0 || chkjpg1 == 0)
        {   
            // label the files with three digits
            sprintf(fname, "%03d.jpg", counter);

            // next file in line
            temp = fopen(fname, "w");

            // CRANK IT UP
            counter++;

            // new file with buffer
            fwrite(buffer, sizeof(buffer), 1, temp);
        }
        else if (counter > 0)
        {
            // put jpg into temp
            fwrite(buffer, sizeof(buffer), 1, temp);            
        }

        fread(buffer, sizeof(buffer), 1, fimg);
    }   

    fclose(fimg);

    return 0;
}