求高手进来帮解决有关huffman图片压缩还原用C语言实现，已经列出部分主程序，请教高手帮忙完成整嗰可以运行的程序
效果如图所示
实现代码
（1）压缩主函数
int Huffman_Compression(char * infilename, char * outfilename)
{
if ((ifile = fopen (infilename, "rb")) != NULL)
{
fseek (ifile, 0L, 2);
file_size = (unsigned long) ftell (ifile); //获得文件的大小
fseek (ifile, 0L, 0);
Get_frequency_count (); //统计字符频率
Build_initial_heap (); //建立初始堆
Build_code_tree (); //构造编码树
if (!Generate_code_table ()) //产生编码表
{
printf ("ERROR! Cannot Compress.\n");
return 0;
}
else
{
if ((ofile = fopen (outfilename, "wb")) != NULL)
{//写文件头
fwrite (&file_size, sizeof (file_size), 1, ofile);
fwrite (code, 2, 256, ofile);
fwrite (code_length, 1, 256, ofile);
fseek (ifile, 0L, 0);
Compress_image (); //压缩数据
fclose (ofile);
}
else
{
printf("\nERROR: Couldn't create output file %s\n", outfilename);
return 0;
}
}
fclose (ifile);
}
else
{
printf ("\nERROR: %s -- File not found!\n", infilename);
return 0;
}
return 1;
}
（2）相关函数
//统计数据频率
/*通常在统计文件中字符频率时，耗费时间长，占用内存空间大。为降低时间复杂度和空间复杂度，这里直接用字符的十进制值作数组下标，在扫描过程中依次增加该字符出现的频率。*/
void Get_frequency_count ()
{
register unsigned long loop;
for (loop = 0; loop < file_size; loop++)
frequency_count[getc (ifile)]++;
}
//建立初始堆
void Build_initial_heap ()
{
void reheap ();
register unsigned short loop;
heap_length = 0;
for (loop = 0; loop < 256; loop++)
if (frequency_count[loop])
heap[++heap_length] = (unsigned long) loop;
for (loop = heap_length; loop > 0; loop--)
reheap (loop);
}
//构造编码树
/*因为每个字节可表示的符号个数为256 个(对应于256 种颜色)，所以二叉树有256 个叶结点，根据二叉树的性质总结点数为2•256- 1 = 511 个结点。这里用0～255 个元素来依次对应256 种颜色。由第256 以后的元素来依次对应形成的各个父结点的信息，即父结点的编号从256 开始。*/
void Build_code_tree ()
{
void reheap ();
register unsigned short findex;
register unsigned long heap_value;
while (heap_length != 1)
{
heap_value = heap[1];
heap[1] = heap[heap_length--];
reheap (1);
findex = heap_length + 255;
frequency_count[findex] = frequency_count[heap[1]] +
frequency_count[heap_value];
father[heap_value] = findex;
father[heap[1]] = -findex;
heap[1] = findex;
reheap (1);
}
father[256] = 0;
}
//生成编码表
unsigned short Generate_code_table ()
{
register unsigned short loop;
register unsigned short current_length;
register unsigned short current_bit;
unsigned short bitcode;
short parent;
for (loop = 0; loop < 256; loop++)
if (frequency_count[loop])
{
current_length = bitcode = 0;
current_bit = 1;
parent = father[loop];
while (parent)
{
if (parent < 0)
{
bitcode += current_bit;
parent = -parent;
}
parent = father[parent];
current_bit <<= 1;
current_length++;
}
code[loop] = bitcode;
if (current_length > 16) return (0);
else
code_length[loop] = (unsigned char) current_length;
}
else code[loop] = code_length[loop] = 0;
return (1);
}
//压缩数据
void Compress_image ()
{
register unsigned int thebyte = 0;
register short loop1;
register unsigned short current_code;
register unsigned long loop;
unsigned short current_length, dvalue;
unsigned long curbyte = 0;
short curbit = 7;
for (loop = 0L; loop < file_size; loop++)
{
dvalue = (unsigned short) getc (ifile);
current_code = code[dvalue];
current_length = (unsigned short) code_length[dvalue];
for (loop1 = current_length-1; loop1 >= 0; --loop1)
{
if ((current_code >> loop1) & 1)
thebyte |= (char) (1 << curbit);
if (--curbit < 0)
{
putc (thebyte, ofile);
thebyte = 0;
curbyte++;
curbit = 7;
}
}
}
putc (thebyte, ofile);
compress_charcount = ++curbyte;
}
实现代码
（1）解压主函数
int Huffman_Decompression(char * infilename, char * outfilename)
{
if ((ifile = fopen (infilename, "rb")) != NULL)
{ //读取文件头
fread (&file_size, sizeof (file_size), 1, ifile);
fread (code, 2, 256, ifile);
fread (code_length, 1, 256, ifile);
Build_decomp_tree (); //创建解压缩树
if ((ofile = fopen (outfilename, "wb")) != NULL){
Decompress_image(); //解压缩数据
fclose (ofile);}
else {
printf ("\nERROR: Couldn't create output file %s\n", outfilename);
return 0; }
fclose (ifile);
}
else
{
printf ("\nERROR: %s -- File not found!\n", infilename);
return 0;
}
return 1;
}
（2）相关函数
void Build_decomp_tree () //创建解压缩树
{
register unsigned short loop1, current_index;
unsigned short loop, current_node = 1;
decomp_tree[1] = 1;
for (loop = 0; loop < 256; loop++)
{
if (code_length[loop])
{
current_index = 1;
for (loop1 = code_length[loop] - 1; loop1 > 0; loop1--)
{
current_index = (decomp_tree[current_index] << 1) +
((code[loop] >> loop1) & 1);
if (!(decomp_tree[current_index]))
decomp_tree[current_index] = ++current_node;
}
decomp_tree[(decomp_tree[current_index] << 1) + (code[loop] & 1)] = -loop;
}
}
}
void Decompress_image () //进行解压缩操作
{
register unsigned short cindex = 1;
register char curchar;
register short bitshift;
unsigned long charcount = 0L;
while (charcount < file_size)
{
curchar = (char) getc (ifile);
for (bitshift = 7; bitshift >= 0; --bitshift)
{
cindex = (cindex << 1) + ((curchar >> bitshift) & 1);
if (decomp_tree[cindex] <= 0) {
putc ((int) (-decomp_tree[cindex]), ofile);
if ((++charcount) == file_size) bitshift = 0;
else cindex = 1; }
else cindex = decomp_tree[cindex];
}
}
}
