Base64。 我无法解码图像文件

Question

我的代码有问题。 我得到了bmp图像并在base64中对其进行了编码。然后我想对其进行解码，但是我的PC上说：“无法加载图像'OUTPUT.PNG'”。如何解决？

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


const unsigned char base64[] = {
    // ASCII table 
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 62, 64, 64, 64, 64, 63,
    52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 64, 64, 64, 64, 64, 64,
    64,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,
    15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 64, 64, 64, 64, 64,
    64, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
    41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64  
};

void deblock(const unsigned char *in, const unsigned char *base64, FILE * OutputFile, int len)
{
 if (base64[(unsigned char)in[0]] < 64  && base64[(unsigned char)in[1]] < 64)   
    fprintf(OutputFile, "%c",(base64[(unsigned char)in[0]] << 2 | base64[(unsigned char)in[1]] >> 4));
 if (base64[(unsigned char)in[1]] < 64  && base64[(unsigned char)in[2]] < 64)       
    fprintf(OutputFile, "%c",(base64[(unsigned char)in[1]] << 4 | base64[(unsigned char)in[2]] >> 2));
 if (base64[(unsigned char)in[2]] < 64  && base64[(unsigned char)in[3]] < 64)   
    fprintf(OutputFile, "%c", base64[(unsigned char)in[2]] << 6 | base64[(unsigned char)in[3]]);
}   

void decode (FILE *InputFile, FILE *OutputFile)
{

    int len = 0;
    unsigned char buffer[4] = "\0"; 

    while ((len = fread(buffer,sizeof(unsigned char),4,InputFile)) > 0)
    {   
        deblock(buffer,base64,OutputFile,len);
    }   
}


int check_decode(FILE *file1, FILE *file2)
{
    int k = 0;

    fseek (file1, 0, SEEK_END);
    if (0 == ((ftell(file1)) % 4))
    {
        fseek(file1,0,SEEK_SET);
        decode(file1,file2);
    }
    else 
    {
        k = -1;
    }
    return k;
} 


int main() 
{
    FILE *file1 = NULL;
    FILE *file2 = NULL;
    if (NULL == (file1 = fopen("INPUT1.txt", "rb")))
    {   
        printf("Can't open INPUT file!");
        return -1;
    }
    if (NULL == (file2 = fopen("OUTPUT.png", "wb    ")))
    {
        printf("Can't create OUTPUT file");
        fclose(file1);
        return -1;
    }   
    if ( -1 == check_decode(file1, file2)       )
    {
        printf("Eto ne base64\n ");
        return -1;
    }
    assert(file1);
    assert(file2);
    fclose(file1);
    fclose(file2);
    return 0;
}

我使用此网站对我的图片进行编码http://www.base64-image.de/step-2.php

Answer 1

我得到了bmp图像并在base64中对其进行了编码。然后我想对其进行解码，但是我的PC上说：“无法加载图像'OUTPUT.PNG'”。如何解决？

由于获得了bmp图像 ，因此只需创建OUTPUT.bmp而不是OUTPUT.png 。