📄 b97.c
字号:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <crblib/inc.h>
#include "coder.h"
#define SHIFT_BASE tune_param
#define SHIFT_ROUNDER (1<<(SHIFT_BASE-1))
#define ONE (1<<(SHIFT_BASE))
#define SHIFT(x) (((x)+SHIFT_ROUNDER)>>SHIFT_BASE)
#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))
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;
for(x=0;x<half;x++) {
*low = ptr[0];
*high = ptr[1];
if ( x == half-1 ) *high -= SHIFT(C_A*( ptr[0] + ptr[0] ));
else *high -= SHIFT(C_A*( ptr[0] + ptr[2] ));
if ( x == 0 ) *low -= SHIFT(C_B*( high[0] + high[0]));
else *low -= SHIFT(C_B*( high[0] + high[-1]));
low++; high++; ptr += 2;
}
low = to; high = to + half;
for(x=0;x<half;x++) {
if ( x == half-1 ) *high += SHIFT(C_C*( low[0] + low[0] ));
else *high += SHIFT(C_C*( low[0] + low[1] ));
if ( x == 0 ) *low += SHIFT(C_D*( high[0] + high[0]));
else *low += SHIFT(C_D*( high[0] + high[-1]));
low++; high++;
}
}
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<half;x++) {
if ( x == 0 ) *low -= SHIFT(C_D*( high[0] + high[0]));
else *low -= SHIFT(C_D*( high[0] + high[-1]));
low++; high++;
}
low = from; high = from + half;
for(x=0;x<half;x++) {
if ( x == half-1 ) *high -= SHIFT(C_C*( low[0] + low[0] ));
else *high -= SHIFT(C_C*( low[0] + low[1] ));
low++; high++;
}
low = from; high = from + half; ptr = to;
for(x=0;x<half;x++) {
if ( x == 0 ) ptr[0] = *low + SHIFT(C_B*( high[0] + high[0]));
else ptr[0] = *low + SHIFT(C_B*( high[0] + high[-1]));
low++; high++; ptr += 2;
}
low = from; high = from + half; ptr = to;
for(x=0;x<half;x++) {
if ( x == half-1 ) ptr[1] = *high + SHIFT(C_A*( ptr[0] + ptr[0] ));
else ptr[1] = *high + SHIFT(C_A*( ptr[0] + ptr[2] ));
low++; high++; ptr += 2;
}
}
void b97_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 b97Quad(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);
}
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -