www.pudn.com > wavecode.rar > l97.c

#include  
#include  
#include  
#include  
 
#define MULT(x,y)	((((x)*(y))+16383)>>15) 
 
/********** 
 
#define ONE	(1<<15) 
#define	C_A	((int)(ONE* 1.586134342  + 0.5)) 
#define C_B	((int)(ONE* 0.05298011854+ 0.5)) 
#define C_C ((int)(ONE* 0.8829110762 + 0.5)) 
#define C_D	((int)(ONE* 0.4435068522 + 0.5)) 
 
***********/ 
 
#define	C_A	51974 
#define C_B	1736 
#define C_C	28931 
#define C_D	14533 
 
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] - MULT(C_A,( ptr[0] + ptr[2] )); 
		*low  = ptr[0] - MULT(C_B,( high[0] + high[0])); 
		low++; high++; ptr += 2; 
 
	for(x=half-2;x--;) { 
		*high = ptr[1] - MULT(C_A,( ptr[0] + ptr[2] )); 
		*low  = ptr[0] - MULT(C_B,( high[0] + high[-1])); 
		low++; high++; ptr += 2; 
	} 
 
		*high = ptr[1] - MULT(C_A,( ptr[0] + ptr[0] )); 
		*low  = ptr[0] - MULT(C_B,( high[0] + high[-1])); 
 
	low  = to; high = to + half; 
 
		*high += MULT(C_C,( low[0] + low[1] )); 
		*low  += MULT(C_D,( high[0] + high[0])); 
		low++; high++; 
 
	for(x=half-2;x--;) { 
		*high += MULT(C_C,( low[0] + low[1] )); 
		*low  += MULT(C_D,( high[0] + high[-1])); 
		low++; high++; 
	} 
 
		*high += MULT(C_C,( low[0] + low[0] )); 
		*low  += MULT(C_D,( high[0] + high[-1])); 
 
} 
 
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; 
	for(x=0;x> 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 l97Quad(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); 
}