www.pudn.com > xiaobo.zip.zip > cdf24.c

#include  
#include  
#include  
#include  
 
#define memcpyints(to,from,len)	memcpy(to,from,(len)*sizeof(int)) 
 
static void do_tdec_line(int * to,int *from,int len) 
{ 
int x,*ptr,*low,*high,half,A; //,B; 
 
	if ( len <= 2 ) errexit("special-cased to len > 2 , scumbag"); 
	if ( len&1 ) errexit("len shouldn't be odd"); 
 
	half = len>>1; 
 
	high = to + half; 
	ptr = from; 
	for(x=0;x<(half-1);x++) { 
		*high++ = ptr[1] - ((ptr[2] + ptr[0])>>1); 
		ptr += 2; 
	} 
	*high = ptr[1] - ptr[0]; 
 
	low  = to; 
	high = to + half; 
	ptr = from; 
	for(x=0;x>1) ; 
		} else if ( x == 1 ||  x == (half-1)) { 
			A = ((high[0] + high[-1])>>2) ; 
		} else { 
			A = ((19*(high[0] + high[-1]) - 3*(high[1] + high[-2]))>>6) ; 
		} 
		*low = *ptr + A; 
		ptr += 2; high++; low++; 
	} 
} 
 
static void un_tdec_line(int *to,int *from,int len) 
{ 
int x,*ptr,*low,*high,half,A; //,B; 
 
	half = len>>1; 
 
	low  = from; 
	ptr = to; 
	high = from + half; 
	for(x=0;x>1) ; 
		} else if ( x == 1 ||  x == (half-1)) { 
			A = ((high[0] + high[-1])>>2) ; 
		} else { 
			A = ((19*(high[0] + high[-1]) - 3*(high[1] + high[-2]))>>6) ; 
		} 
		*ptr = *low - A; 
		ptr += 2; high++; low ++; 
	} 
 
	high = from + half; 
	ptr = to; 
	for(x=0;x<(half-1);x++) { 
		ptr[1] = (*high++) + ((ptr[2] + ptr[0])>>1); 
		ptr += 2; 
	} 
	ptr[1] = *high + ptr[0]; 
} 
 
void cdf24_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); 
}