www.pudn.com > xiaobo.zip.zip > cdf22.c

#include  
#include  
#include  
#include  
 
static void do_tdec_line(int * to,int *from,int len) 
{ 
int x,*ptr,*low,*high,half; 
 
	half = len>>1; 
 
	assert( (len & 1) == 0 ); 
	assert( half >= 2 ); 
 
	low  = to; high = to + half; ptr = from; 
 
	*high = ptr[1] - ((ptr[2] + ptr[0])>>1); 
	*low  = ptr[0] + ((high[0] )>>1); 
	ptr += 2; high++; low++; 
 
	for(x=(half-2);x--;) { 
		*high = ptr[1] - ((ptr[2] + ptr[0])>>1); 
		*low =  ptr[0] + ((high[0] + high[-1])>>2); 
		ptr += 2; high++; low++; 
	} 
 
	*high = ptr[1] - ptr[0]; 
	*low = *ptr + ((high[0] + high[-1])>>2); 
 
} 
 
static void un_tdec_line(int *to,int *from,int len) 
{ 
int x,*ptr,*low,*high,half; 
 
	half = len>>1; 
	low  = from; high = from + half; ptr = to; 
	 
#if 1 
	ptr[0] = low[0] - ((high[0])>>1); 
	ptr += 2; high++; low++; 
	for(x=(half-1);x--;) { 
		ptr[ 0] = low[0]  - ((high[0] + high[-1])>>2); 
		ptr[-1] = high[-1] + ((ptr[0] + ptr[-2])>>1); 
		ptr += 2; high++; low++; 
	} 
	ptr[-1] = high[-1] + ptr[-2]; 
#else 
	/*#*/{ 
	int hi,lh,cur,last; 
 
	hi = *high++; 
	ptr[0] = cur = (*low++) - (hi>>1); 
	ptr += 2; 
	for(x=(half-1);x--;) { 
		last = cur;	lh = hi; 
		hi = *high++;  
		ptr[ 0] = cur = (*low++)  - ((hi + lh)>>2); 
		ptr[-1] = lh + ((cur + last)>>1); 
		ptr += 2; 
	} 
	ptr[-1] = hi + cur; 
	/*#*/} 
#endif 
 
} 
 
void cdf22_2D(int **rows, int width, int height, int levels,bool inverse) 
{ 
int x, y, w, h, l; 
int *buffer,*tempbuf,*temprow; 
 
    if (width%(1 << (levels+1)) || height%(1 << (levels+1))) 
		errexit("width and height must be divisible by 2^(levels+1)"); 
   
    /* Allocate a work array (for transposing columns) */ 
     
   	if ( (buffer = newarray(int,height+max(width,height)+height)) == NULL ) 
		errexit("malloc failed"); 
	temprow = buffer+height; 
	tempbuf = buffer+height+height; 
 
	if ( !inverse ) { 
 
		for (l = 0; l < levels; l++) { 
			w = width >> l; 
			h = height >> l; 
       
			/* Rows */ 
	 
			do_tdec_line(temprow,rows[h-1],w); 
			for (y = h-2; y >=0; y--) { 
				do_tdec_line(rows[y+1],rows[y],w); 
			} 
	 
			/* Columns */ 
	 
			for (x = 0; x < w; x++) { 
					for (y = 1; y < h; y++) buffer[y-1] = rows[y][x]; 
					buffer[h-1] = temprow[x]; 
				do_tdec_line(tempbuf,buffer,h); 
					for (y = 0; y < h; y++) rows[y][x] = tempbuf[y]; 
			} 
		} 
 
    } else { 
 
		for (l = levels-1; l >= 0; l--) { /** backwards in scale **/ 
			w = width >> l; 
			h = height >> l; 
 
			/* Columns */ 
	 
			for (x = 0; x < w; x++) { 
					for (y = 0; y < h; y++) buffer[y] = rows[y][x]; 
				un_tdec_line(tempbuf,buffer,h); 
					for (y = 0; y < h-1; y++) rows[y+1][x] = tempbuf[y]; 
					temprow[x] = tempbuf[h-1]; 
			} 
 
			/* Rows */ 
			for (y = 0; y < h-1; y++) { 
				un_tdec_line(rows[y],rows[y+1],w); 
			}  
			un_tdec_line(rows[h-1],temprow,w); 
		} 
	} 
 
	free(buffer); 
} 
 
 
void cdfQuad(int *band,int w,int h,int fullw,bool inverse) 
{ 
int x, y; 
int *buffer,*tempbuf,*bptr,*temprow; 
 
   	if ( (buffer = newarray(int,h+h+max(w,h))) == NULL ) { 
		errputs("malloc failed"); exit(10); 
	} 
	temprow = buffer+h; 
	tempbuf = buffer+h+h; 
   
	if ( !inverse ) { /* forward transform. */ 
	 
		bptr = band + (h-1)*fullw; 
		do_tdec_line(temprow,bptr,w); 
		for (y = (h-1); y--;) { 
			bptr -= fullw; 
			do_tdec_line(bptr+fullw,bptr,w); 
		} 
     
		for (x = 0; x < w; x++) { 
			bptr = band + x + fullw; 
			for (y = 0; y < (h-1); y++) { buffer[y] = *bptr; bptr += fullw; } 
			buffer[h-1] = temprow[x]; 
			do_tdec_line(tempbuf,buffer,h); 
			bptr = band + x; 
			for (y = 0; y < h; y++) { *bptr = tempbuf[y]; bptr += fullw; } 
		} 
 
    } else { 
 
		for (x = 0; x < w; x++) { 
			bptr = band + x; 
			for (y = 0; y < h; y++) { buffer[y] = *bptr; bptr += fullw; } 
			un_tdec_line(tempbuf,buffer,h); 
			bptr = band + x + fullw; 
			for (y = 0; y < h-1; y++) { *bptr = tempbuf[y]; bptr += fullw; } 
			temprow[x] = tempbuf[h-1]; 
		} 
 
		bptr = band; 
		for (y = (h-1); y--; ){ 
			un_tdec_line(bptr,bptr+fullw,w); 
			bptr += fullw; 
		} 
		un_tdec_line(bptr,temprow,w); 
 
	} 
 
	free(buffer); 
}