summaryrefslogtreecommitdiffstats
path: root/fitsy/hdecompress.c
diff options
context:
space:
mode:
Diffstat (limited to 'fitsy/hdecompress.c')
-rw-r--r--fitsy/hdecompress.c2619
1 files changed, 2619 insertions, 0 deletions
diff --git a/fitsy/hdecompress.c b/fitsy/hdecompress.c
new file mode 100644
index 0000000..06d1c7a
--- /dev/null
+++ b/fitsy/hdecompress.c
@@ -0,0 +1,2619 @@
+/* #########################################################################
+These routines to apply the H-compress decompression algorithm to a 2-D Fits
+image were written by R. White at the STScI and were obtained from the STScI at
+http://www.stsci.edu/software/hcompress.html
+
+This source file is a concatination of the following sources files in the
+original distribution
+ hinv.c
+ hsmooth.c
+ undigitize.c
+ decode.c
+ dodecode.c
+ qtree_decode.c
+ qread.c
+ bit_input.c
+
+
+The following modifications have been made to the original code:
+
+ - commented out redundant "include" statements
+ - added the nextchar global variable
+ - changed all the 'extern' declarations to 'static', since all the routines are in
+ the same source file
+ - changed the first parameter in decode (and in lower level routines from a file stream
+ to a char array
+ - modified the myread routine, and lower level byte reading routines, to copy
+ the input bytes to a char array, instead of reading them from a file stream
+ - changed the function declarations to the more modern ANSI C style
+ - changed calls to printf and perror to call the CFITSIO ffpmsg routine
+ - replace "exit" statements with "return" statements
+
+ ############################################################################ */
+
+#include <stdio.h>
+#include <math.h>
+#include <stdlib.h>
+#include <string.h>
+/*#include "fitsio2.h"*/
+#define LONGLONG long long
+#define DATA_DECOMPRESSION_ERR 0
+
+static void ffpmsg(const char* str) {}
+
+/* WDP added test to see if min and max are already defined */
+#ifndef min
+#define min(a,b) (((a)<(b))?(a):(b))
+#endif
+#ifndef max
+#define max(a,b) (((a)>(b))?(a):(b))
+#endif
+
+static long nextchar;
+
+static int decode(unsigned char *infile, int *a, int *nx, int *ny, int *scale);
+static int decode64(unsigned char *infile, LONGLONG *a, int *nx, int *ny, int *scale);
+static int hinv(int a[], int nx, int ny, int smooth ,int scale);
+static int hinv64(LONGLONG a[], int nx, int ny, int smooth ,int scale);
+static void undigitize(int a[], int nx, int ny, int scale);
+static void undigitize64(LONGLONG a[], int nx, int ny, int scale);
+static void unshuffle(int a[], int n, int n2, int tmp[]);
+static void unshuffle64(LONGLONG a[], int n, int n2, LONGLONG tmp[]);
+static void hsmooth(int a[], int nxtop, int nytop, int ny, int scale);
+static void hsmooth64(LONGLONG a[], int nxtop, int nytop, int ny, int scale);
+static void qread(unsigned char *infile,char *a, int n);
+static int readint(unsigned char *infile);
+static LONGLONG readlonglong(unsigned char *infile);
+static int dodecode(unsigned char *infile, int a[], int nx, int ny, unsigned char nbitplanes[3]);
+static int dodecode64(unsigned char *infile, LONGLONG a[], int nx, int ny, unsigned char nbitplanes[3]);
+static int qtree_decode(unsigned char *infile, int a[], int n, int nqx, int nqy, int nbitplanes);
+static int qtree_decode64(unsigned char *infile, LONGLONG a[], int n, int nqx, int nqy, int nbitplanes);
+static void start_inputing_bits();
+static int input_bit(unsigned char *infile);
+static int input_nbits(unsigned char *infile, int n);
+/* make input_nybble a separate routine, for added effiency */
+/* #define input_nybble(infile) input_nbits(infile,4) */
+static int input_nybble(unsigned char *infile);
+static int input_nnybble(unsigned char *infile, int n, unsigned char *array);
+
+static void qtree_expand(unsigned char *infile, unsigned char a[], int nx, int ny, unsigned char b[]);
+static void qtree_bitins(unsigned char a[], int nx, int ny, int b[], int n, int bit);
+static void qtree_bitins64(unsigned char a[], int nx, int ny, LONGLONG b[], int n, int bit);
+static void qtree_copy(unsigned char a[], int nx, int ny, unsigned char b[], int n);
+static void read_bdirect(unsigned char *infile, int a[], int n, int nqx, int nqy, unsigned char scratch[], int bit);
+static void read_bdirect64(unsigned char *infile, LONGLONG a[], int n, int nqx, int nqy, unsigned char scratch[], int bit);
+static int input_huffman(unsigned char *infile);
+
+/* ---------------------------------------------------------------------- */
+int fits_hdecompress(unsigned char *input, int smooth, int *a, int *ny, int *nx,
+ int *scale, int *status)
+{
+ /*
+ decompress the input byte stream using the H-compress algorithm
+
+ input - input array of compressed bytes
+ a - pre-allocated array to hold the output uncompressed image
+ nx - returned X axis size
+ ny - returned Y axis size
+
+ NOTE: the nx and ny dimensions as defined within this code are reversed from
+ the usual FITS notation. ny is the fastest varying dimension, which is
+ usually considered the X axis in the FITS image display
+
+ */
+int stat;
+
+ if (*status > 0) return(*status);
+
+ /* decode the input array */
+
+ stat = decode(input, a, nx, ny, scale);
+ *status = stat;
+ if (stat) return(*status);
+
+ /*
+ * Un-Digitize
+ */
+ undigitize(a, *nx, *ny, *scale);
+
+ /*
+ * Inverse H-transform
+ */
+ stat = hinv(a, *nx, *ny, smooth, *scale);
+ *status = stat;
+
+ return(*status);
+}
+/* ---------------------------------------------------------------------- */
+int fits_hdecompress64(unsigned char *input, int smooth, LONGLONG *a, int *ny, int *nx,
+ int *scale, int *status)
+{
+ /*
+ decompress the input byte stream using the H-compress algorithm
+
+ input - input array of compressed bytes
+ a - pre-allocated array to hold the output uncompressed image
+ nx - returned X axis size
+ ny - returned Y axis size
+
+ NOTE: the nx and ny dimensions as defined within this code are reversed from
+ the usual FITS notation. ny is the fastest varying dimension, which is
+ usually considered the X axis in the FITS image display
+
+ */
+ int stat, *iarray, ii, nval;
+
+ if (*status > 0) return(*status);
+
+ /* decode the input array */
+
+ stat = decode64(input, a, nx, ny, scale);
+ *status = stat;
+ if (stat) return(*status);
+
+ /*
+ * Un-Digitize
+ */
+ undigitize64(a, *nx, *ny, *scale);
+
+ /*
+ * Inverse H-transform
+ */
+ stat = hinv64(a, *nx, *ny, smooth, *scale);
+
+ *status = stat;
+
+ /* pack the I*8 values back into an I*4 array */
+ iarray = (int *) a;
+ nval = (*nx) * (*ny);
+
+ for (ii = 0; ii < nval; ii++)
+ iarray[ii] = (int) a[ii];
+
+ return(*status);
+}
+
+/* ############################################################################ */
+/* ############################################################################ */
+
+/* Copyright (c) 1993 Association of Universities for Research
+ * in Astronomy. All rights reserved. Produced under National
+ * Aeronautics and Space Administration Contract No. NAS5-26555.
+ */
+/* hinv.c Inverse H-transform of NX x NY integer image
+ *
+ * Programmer: R. White Date: 23 July 1993
+ */
+
+/* ############################################################################ */
+static int
+hinv(int a[], int nx, int ny, int smooth ,int scale)
+/*
+int smooth; 0 for no smoothing, else smooth during inversion
+int scale; used if smoothing is specified
+*/
+{
+int nmax, log2n, i, j, k;
+int nxtop,nytop,nxf,nyf,c;
+int oddx,oddy;
+int shift, bit0, bit1, bit2, mask0, mask1, mask2,
+ prnd0, prnd1, prnd2, nrnd0, nrnd1, nrnd2, lowbit0, lowbit1;
+int h0, hx, hy, hc;
+int s10, s00;
+int *tmp;
+
+ /*
+ * log2n is log2 of max(nx,ny) rounded up to next power of 2
+ */
+ nmax = (nx>ny) ? nx : ny;
+ log2n = (int) (log((float) nmax)/log(2.0)+0.5);
+ if ( nmax > (1<<log2n) ) {
+ log2n += 1;
+ }
+ /*
+ * get temporary storage for shuffling elements
+ */
+ tmp = (int *) malloc(((nmax+1)/2)*sizeof(int));
+ if (tmp == (int *) NULL) {
+ ffpmsg("hinv: insufficient memory");
+ return(DATA_DECOMPRESSION_ERR);
+ }
+ /*
+ * set up masks, rounding parameters
+ */
+ shift = 1;
+ bit0 = 1 << (log2n - 1);
+ bit1 = bit0 << 1;
+ bit2 = bit0 << 2;
+ mask0 = -bit0;
+ mask1 = mask0 << 1;
+ mask2 = mask0 << 2;
+ prnd0 = bit0 >> 1;
+ prnd1 = bit1 >> 1;
+ prnd2 = bit2 >> 1;
+ nrnd0 = prnd0 - 1;
+ nrnd1 = prnd1 - 1;
+ nrnd2 = prnd2 - 1;
+ /*
+ * round h0 to multiple of bit2
+ */
+ a[0] = (a[0] + ((a[0] >= 0) ? prnd2 : nrnd2)) & mask2;
+ /*
+ * do log2n expansions
+ *
+ * We're indexing a as a 2-D array with dimensions (nx,ny).
+ */
+ nxtop = 1;
+ nytop = 1;
+ nxf = nx;
+ nyf = ny;
+ c = 1<<log2n;
+ for (k = log2n-1; k>=0; k--) {
+ /*
+ * this somewhat cryptic code generates the sequence
+ * ntop[k-1] = (ntop[k]+1)/2, where ntop[log2n] = n
+ */
+ c = c>>1;
+ nxtop = nxtop<<1;
+ nytop = nytop<<1;
+ if (nxf <= c) { nxtop -= 1; } else { nxf -= c; }
+ if (nyf <= c) { nytop -= 1; } else { nyf -= c; }
+ /*
+ * double shift and fix nrnd0 (because prnd0=0) on last pass
+ */
+ if (k == 0) {
+ nrnd0 = 0;
+ shift = 2;
+ }
+ /*
+ * unshuffle in each dimension to interleave coefficients
+ */
+ for (i = 0; i<nxtop; i++) {
+ unshuffle(&a[ny*i],nytop,1,tmp);
+ }
+ for (j = 0; j<nytop; j++) {
+ unshuffle(&a[j],nxtop,ny,tmp);
+ }
+ /*
+ * smooth by interpolating coefficients if SMOOTH != 0
+ */
+ if (smooth) hsmooth(a,nxtop,nytop,ny,scale);
+ oddx = nxtop % 2;
+ oddy = nytop % 2;
+ for (i = 0; i<nxtop-oddx; i += 2) {
+ s00 = ny*i; /* s00 is index of a[i,j] */
+ s10 = s00+ny; /* s10 is index of a[i+1,j] */
+ for (j = 0; j<nytop-oddy; j += 2) {
+ h0 = a[s00 ];
+ hx = a[s10 ];
+ hy = a[s00+1];
+ hc = a[s10+1];
+ /*
+ * round hx and hy to multiple of bit1, hc to multiple of bit0
+ * h0 is already a multiple of bit2
+ */
+ hx = (hx + ((hx >= 0) ? prnd1 : nrnd1)) & mask1;
+ hy = (hy + ((hy >= 0) ? prnd1 : nrnd1)) & mask1;
+ hc = (hc + ((hc >= 0) ? prnd0 : nrnd0)) & mask0;
+ /*
+ * propagate bit0 of hc to hx,hy
+ */
+ lowbit0 = hc & bit0;
+ hx = (hx >= 0) ? (hx - lowbit0) : (hx + lowbit0);
+ hy = (hy >= 0) ? (hy - lowbit0) : (hy + lowbit0);
+ /*
+ * Propagate bits 0 and 1 of hc,hx,hy to h0.
+ * This could be simplified if we assume h0>0, but then
+ * the inversion would not be lossless for images with
+ * negative pixels.
+ */
+ lowbit1 = (hc ^ hx ^ hy) & bit1;
+ h0 = (h0 >= 0)
+ ? (h0 + lowbit0 - lowbit1)
+ : (h0 + ((lowbit0 == 0) ? lowbit1 : (lowbit0-lowbit1)));
+ /*
+ * Divide sums by 2 (4 last time)
+ */
+ a[s10+1] = (h0 + hx + hy + hc) >> shift;
+ a[s10 ] = (h0 + hx - hy - hc) >> shift;
+ a[s00+1] = (h0 - hx + hy - hc) >> shift;
+ a[s00 ] = (h0 - hx - hy + hc) >> shift;
+ s00 += 2;
+ s10 += 2;
+ }
+ if (oddy) {
+ /*
+ * do last element in row if row length is odd
+ * s00+1, s10+1 are off edge
+ */
+ h0 = a[s00 ];
+ hx = a[s10 ];
+ hx = ((hx >= 0) ? (hx+prnd1) : (hx+nrnd1)) & mask1;
+ lowbit1 = hx & bit1;
+ h0 = (h0 >= 0) ? (h0 - lowbit1) : (h0 + lowbit1);
+ a[s10 ] = (h0 + hx) >> shift;
+ a[s00 ] = (h0 - hx) >> shift;
+ }
+ }
+ if (oddx) {
+ /*
+ * do last row if column length is odd
+ * s10, s10+1 are off edge
+ */
+ s00 = ny*i;
+ for (j = 0; j<nytop-oddy; j += 2) {
+ h0 = a[s00 ];
+ hy = a[s00+1];
+ hy = ((hy >= 0) ? (hy+prnd1) : (hy+nrnd1)) & mask1;
+ lowbit1 = hy & bit1;
+ h0 = (h0 >= 0) ? (h0 - lowbit1) : (h0 + lowbit1);
+ a[s00+1] = (h0 + hy) >> shift;
+ a[s00 ] = (h0 - hy) >> shift;
+ s00 += 2;
+ }
+ if (oddy) {
+ /*
+ * do corner element if both row and column lengths are odd
+ * s00+1, s10, s10+1 are off edge
+ */
+ h0 = a[s00 ];
+ a[s00 ] = h0 >> shift;
+ }
+ }
+ /*
+ * divide all the masks and rounding values by 2
+ */
+ bit2 = bit1;
+ bit1 = bit0;
+ bit0 = bit0 >> 1;
+ mask1 = mask0;
+ mask0 = mask0 >> 1;
+ prnd1 = prnd0;
+ prnd0 = prnd0 >> 1;
+ nrnd1 = nrnd0;
+ nrnd0 = prnd0 - 1;
+ }
+ free(tmp);
+ return(0);
+}
+/* ############################################################################ */
+static int
+hinv64(LONGLONG a[], int nx, int ny, int smooth ,int scale)
+/*
+int smooth; 0 for no smoothing, else smooth during inversion
+int scale; used if smoothing is specified
+*/
+{
+int nmax, log2n, i, j, k;
+int nxtop,nytop,nxf,nyf,c;
+int oddx,oddy;
+int shift;
+LONGLONG mask0, mask1, mask2, prnd0, prnd1, prnd2, bit0, bit1, bit2;
+LONGLONG nrnd0, nrnd1, nrnd2, lowbit0, lowbit1;
+LONGLONG h0, hx, hy, hc;
+int s10, s00;
+LONGLONG *tmp;
+
+ /*
+ * log2n is log2 of max(nx,ny) rounded up to next power of 2
+ */
+ nmax = (nx>ny) ? nx : ny;
+ log2n = (int) (log((float) nmax)/log(2.0)+0.5);
+ if ( nmax > (1<<log2n) ) {
+ log2n += 1;
+ }
+ /*
+ * get temporary storage for shuffling elements
+ */
+ tmp = (LONGLONG *) malloc(((nmax+1)/2)*sizeof(LONGLONG));
+ if (tmp == (LONGLONG *) NULL) {
+ ffpmsg("hinv64: insufficient memory");
+ return(DATA_DECOMPRESSION_ERR);
+ }
+ /*
+ * set up masks, rounding parameters
+ */
+ shift = 1;
+ bit0 = ((LONGLONG) 1) << (log2n - 1);
+ bit1 = bit0 << 1;
+ bit2 = bit0 << 2;
+ mask0 = -bit0;
+ mask1 = mask0 << 1;
+ mask2 = mask0 << 2;
+ prnd0 = bit0 >> 1;
+ prnd1 = bit1 >> 1;
+ prnd2 = bit2 >> 1;
+ nrnd0 = prnd0 - 1;
+ nrnd1 = prnd1 - 1;
+ nrnd2 = prnd2 - 1;
+ /*
+ * round h0 to multiple of bit2
+ */
+ a[0] = (a[0] + ((a[0] >= 0) ? prnd2 : nrnd2)) & mask2;
+ /*
+ * do log2n expansions
+ *
+ * We're indexing a as a 2-D array with dimensions (nx,ny).
+ */
+ nxtop = 1;
+ nytop = 1;
+ nxf = nx;
+ nyf = ny;
+ c = 1<<log2n;
+ for (k = log2n-1; k>=0; k--) {
+ /*
+ * this somewhat cryptic code generates the sequence
+ * ntop[k-1] = (ntop[k]+1)/2, where ntop[log2n] = n
+ */
+ c = c>>1;
+ nxtop = nxtop<<1;
+ nytop = nytop<<1;
+ if (nxf <= c) { nxtop -= 1; } else { nxf -= c; }
+ if (nyf <= c) { nytop -= 1; } else { nyf -= c; }
+ /*
+ * double shift and fix nrnd0 (because prnd0=0) on last pass
+ */
+ if (k == 0) {
+ nrnd0 = 0;
+ shift = 2;
+ }
+ /*
+ * unshuffle in each dimension to interleave coefficients
+ */
+ for (i = 0; i<nxtop; i++) {
+ unshuffle64(&a[ny*i],nytop,1,tmp);
+ }
+ for (j = 0; j<nytop; j++) {
+ unshuffle64(&a[j],nxtop,ny,tmp);
+ }
+ /*
+ * smooth by interpolating coefficients if SMOOTH != 0
+ */
+ if (smooth) hsmooth64(a,nxtop,nytop,ny,scale);
+ oddx = nxtop % 2;
+ oddy = nytop % 2;
+ for (i = 0; i<nxtop-oddx; i += 2) {
+ s00 = ny*i; /* s00 is index of a[i,j] */
+ s10 = s00+ny; /* s10 is index of a[i+1,j] */
+ for (j = 0; j<nytop-oddy; j += 2) {
+ h0 = a[s00 ];
+ hx = a[s10 ];
+ hy = a[s00+1];
+ hc = a[s10+1];
+ /*
+ * round hx and hy to multiple of bit1, hc to multiple of bit0
+ * h0 is already a multiple of bit2
+ */
+ hx = (hx + ((hx >= 0) ? prnd1 : nrnd1)) & mask1;
+ hy = (hy + ((hy >= 0) ? prnd1 : nrnd1)) & mask1;
+ hc = (hc + ((hc >= 0) ? prnd0 : nrnd0)) & mask0;
+ /*
+ * propagate bit0 of hc to hx,hy
+ */
+ lowbit0 = hc & bit0;
+ hx = (hx >= 0) ? (hx - lowbit0) : (hx + lowbit0);
+ hy = (hy >= 0) ? (hy - lowbit0) : (hy + lowbit0);
+ /*
+ * Propagate bits 0 and 1 of hc,hx,hy to h0.
+ * This could be simplified if we assume h0>0, but then
+ * the inversion would not be lossless for images with
+ * negative pixels.
+ */
+ lowbit1 = (hc ^ hx ^ hy) & bit1;
+ h0 = (h0 >= 0)
+ ? (h0 + lowbit0 - lowbit1)
+ : (h0 + ((lowbit0 == 0) ? lowbit1 : (lowbit0-lowbit1)));
+ /*
+ * Divide sums by 2 (4 last time)
+ */
+ a[s10+1] = (h0 + hx + hy + hc) >> shift;
+ a[s10 ] = (h0 + hx - hy - hc) >> shift;
+ a[s00+1] = (h0 - hx + hy - hc) >> shift;
+ a[s00 ] = (h0 - hx - hy + hc) >> shift;
+ s00 += 2;
+ s10 += 2;
+ }
+ if (oddy) {
+ /*
+ * do last element in row if row length is odd
+ * s00+1, s10+1 are off edge
+ */
+ h0 = a[s00 ];
+ hx = a[s10 ];
+ hx = ((hx >= 0) ? (hx+prnd1) : (hx+nrnd1)) & mask1;
+ lowbit1 = hx & bit1;
+ h0 = (h0 >= 0) ? (h0 - lowbit1) : (h0 + lowbit1);
+ a[s10 ] = (h0 + hx) >> shift;
+ a[s00 ] = (h0 - hx) >> shift;
+ }
+ }
+ if (oddx) {
+ /*
+ * do last row if column length is odd
+ * s10, s10+1 are off edge
+ */
+ s00 = ny*i;
+ for (j = 0; j<nytop-oddy; j += 2) {
+ h0 = a[s00 ];
+ hy = a[s00+1];
+ hy = ((hy >= 0) ? (hy+prnd1) : (hy+nrnd1)) & mask1;
+ lowbit1 = hy & bit1;
+ h0 = (h0 >= 0) ? (h0 - lowbit1) : (h0 + lowbit1);
+ a[s00+1] = (h0 + hy) >> shift;
+ a[s00 ] = (h0 - hy) >> shift;
+ s00 += 2;
+ }
+ if (oddy) {
+ /*
+ * do corner element if both row and column lengths are odd
+ * s00+1, s10, s10+1 are off edge
+ */
+ h0 = a[s00 ];
+ a[s00 ] = h0 >> shift;
+ }
+ }
+ /*
+ * divide all the masks and rounding values by 2
+ */
+ bit2 = bit1;
+ bit1 = bit0;
+ bit0 = bit0 >> 1;
+ mask1 = mask0;
+ mask0 = mask0 >> 1;
+ prnd1 = prnd0;
+ prnd0 = prnd0 >> 1;
+ nrnd1 = nrnd0;
+ nrnd0 = prnd0 - 1;
+ }
+ free(tmp);
+ return(0);
+}
+
+/* ############################################################################ */
+static void
+unshuffle(int a[], int n, int n2, int tmp[])
+/*
+int a[]; array to shuffle
+int n; number of elements to shuffle
+int n2; second dimension
+int tmp[]; scratch storage
+*/
+{
+int i;
+int nhalf;
+int *p1, *p2, *pt;
+
+ /*
+ * copy 2nd half of array to tmp
+ */
+ nhalf = (n+1)>>1;
+ pt = tmp;
+ p1 = &a[n2*nhalf]; /* pointer to a[i] */
+ for (i=nhalf; i<n; i++) {
+ *pt = *p1;
+ p1 += n2;
+ pt += 1;
+ }
+ /*
+ * distribute 1st half of array to even elements
+ */
+ p2 = &a[ n2*(nhalf-1) ]; /* pointer to a[i] */
+ p1 = &a[(n2*(nhalf-1))<<1]; /* pointer to a[2*i] */
+ for (i=nhalf-1; i >= 0; i--) {
+ *p1 = *p2;
+ p2 -= n2;
+ p1 -= (n2+n2);
+ }
+ /*
+ * now distribute 2nd half of array (in tmp) to odd elements
+ */
+ pt = tmp;
+ p1 = &a[n2]; /* pointer to a[i] */
+ for (i=1; i<n; i += 2) {
+ *p1 = *pt;
+ p1 += (n2+n2);
+ pt += 1;
+ }
+}
+/* ############################################################################ */
+static void
+unshuffle64(LONGLONG a[], int n, int n2, LONGLONG tmp[])
+/*
+LONGLONG a[]; array to shuffle
+int n; number of elements to shuffle
+int n2; second dimension
+LONGLONG tmp[]; scratch storage
+*/
+{
+int i;
+int nhalf;
+LONGLONG *p1, *p2, *pt;
+
+ /*
+ * copy 2nd half of array to tmp
+ */
+ nhalf = (n+1)>>1;
+ pt = tmp;
+ p1 = &a[n2*nhalf]; /* pointer to a[i] */
+ for (i=nhalf; i<n; i++) {
+ *pt = *p1;
+ p1 += n2;
+ pt += 1;
+ }
+ /*
+ * distribute 1st half of array to even elements
+ */
+ p2 = &a[ n2*(nhalf-1) ]; /* pointer to a[i] */
+ p1 = &a[(n2*(nhalf-1))<<1]; /* pointer to a[2*i] */
+ for (i=nhalf-1; i >= 0; i--) {
+ *p1 = *p2;
+ p2 -= n2;
+ p1 -= (n2+n2);
+ }
+ /*
+ * now distribute 2nd half of array (in tmp) to odd elements
+ */
+ pt = tmp;
+ p1 = &a[n2]; /* pointer to a[i] */
+ for (i=1; i<n; i += 2) {
+ *p1 = *pt;
+ p1 += (n2+n2);
+ pt += 1;
+ }
+}
+
+/* ############################################################################ */
+/* ############################################################################ */
+
+/* Copyright (c) 1993 Association of Universities for Research
+ * in Astronomy. All rights reserved. Produced under National
+ * Aeronautics and Space Administration Contract No. NAS5-26555.
+ */
+/* hsmooth.c Smooth H-transform image by adjusting coefficients toward
+ * interpolated values
+ *
+ * Programmer: R. White Date: 13 April 1992
+ */
+
+/* ############################################################################ */
+static void
+hsmooth(int a[], int nxtop, int nytop, int ny, int scale)
+/*
+int a[]; array of H-transform coefficients
+int nxtop,nytop; size of coefficient block to use
+int ny; actual 1st dimension of array
+int scale; truncation scale factor that was used
+*/
+{
+int i, j;
+int ny2, s10, s00, diff, dmax, dmin, s, smax;
+int hm, h0, hp, hmm, hpm, hmp, hpp, hx2, hy2;
+int m1,m2;
+
+ /*
+ * Maximum change in coefficients is determined by scale factor.
+ * Since we rounded during division (see digitize.c), the biggest
+ * permitted change is scale/2.
+ */
+ smax = (scale >> 1);
+ if (smax <= 0) return;
+ ny2 = ny << 1;
+ /*
+ * We're indexing a as a 2-D array with dimensions (nxtop,ny) of which
+ * only (nxtop,nytop) are used. The coefficients on the edge of the
+ * array are not adjusted (which is why the loops below start at 2
+ * instead of 0 and end at nxtop-2 instead of nxtop.)
+ */
+ /*
+ * Adjust x difference hx
+ */
+ for (i = 2; i<nxtop-2; i += 2) {
+ s00 = ny*i; /* s00 is index of a[i,j] */
+ s10 = s00+ny; /* s10 is index of a[i+1,j] */
+ for (j = 0; j<nytop; j += 2) {
+ /*
+ * hp is h0 (mean value) in next x zone, hm is h0 in previous x zone
+ */
+ hm = a[s00-ny2];
+ h0 = a[s00];
+ hp = a[s00+ny2];
+ /*
+ * diff = 8 * hx slope that would match h0 in neighboring zones
+ */
+ diff = hp-hm;
+ /*
+ * monotonicity constraints on diff
+ */
+ dmax = max( min( (hp-h0), (h0-hm) ), 0 ) << 2;
+ dmin = min( max( (hp-h0), (h0-hm) ), 0 ) << 2;
+ /*
+ * if monotonicity would set slope = 0 then don't change hx.
+ * note dmax>=0, dmin<=0.
+ */
+ if (dmin < dmax) {
+ diff = max( min(diff, dmax), dmin);
+ /*
+ * Compute change in slope limited to range +/- smax.
+ * Careful with rounding negative numbers when using
+ * shift for divide by 8.
+ */
+ s = diff-(a[s10]<<3);
+ s = (s>=0) ? (s>>3) : ((s+7)>>3) ;
+ s = max( min(s, smax), -smax);
+ a[s10] = a[s10]+s;
+ }
+ s00 += 2;
+ s10 += 2;
+ }
+ }
+ /*
+ * Adjust y difference hy
+ */
+ for (i = 0; i<nxtop; i += 2) {
+ s00 = ny*i+2;
+ s10 = s00+ny;
+ for (j = 2; j<nytop-2; j += 2) {
+ hm = a[s00-2];
+ h0 = a[s00];
+ hp = a[s00+2];
+ diff = hp-hm;
+ dmax = max( min( (hp-h0), (h0-hm) ), 0 ) << 2;
+ dmin = min( max( (hp-h0), (h0-hm) ), 0 ) << 2;
+ if (dmin < dmax) {
+ diff = max( min(diff, dmax), dmin);
+ s = diff-(a[s00+1]<<3);
+ s = (s>=0) ? (s>>3) : ((s+7)>>3) ;
+ s = max( min(s, smax), -smax);
+ a[s00+1] = a[s00+1]+s;
+ }
+ s00 += 2;
+ s10 += 2;
+ }
+ }
+ /*
+ * Adjust curvature difference hc
+ */
+ for (i = 2; i<nxtop-2; i += 2) {
+ s00 = ny*i+2;
+ s10 = s00+ny;
+ for (j = 2; j<nytop-2; j += 2) {
+ /*
+ * ------------------ y
+ * | hmp | | hpp | |
+ * ------------------ |
+ * | | h0 | | |
+ * ------------------ -------x
+ * | hmm | | hpm |
+ * ------------------
+ */
+ hmm = a[s00-ny2-2];
+ hpm = a[s00+ny2-2];
+ hmp = a[s00-ny2+2];
+ hpp = a[s00+ny2+2];
+ h0 = a[s00];
+ /*
+ * diff = 64 * hc value that would match h0 in neighboring zones
+ */
+ diff = hpp + hmm - hmp - hpm;
+ /*
+ * 2 times x,y slopes in this zone
+ */
+ hx2 = a[s10 ]<<1;
+ hy2 = a[s00+1]<<1;
+ /*
+ * monotonicity constraints on diff
+ */
+ m1 = min(max(hpp-h0,0)-hx2-hy2, max(h0-hpm,0)+hx2-hy2);
+ m2 = min(max(h0-hmp,0)-hx2+hy2, max(hmm-h0,0)+hx2+hy2);
+ dmax = min(m1,m2) << 4;
+ m1 = max(min(hpp-h0,0)-hx2-hy2, min(h0-hpm,0)+hx2-hy2);
+ m2 = max(min(h0-hmp,0)-hx2+hy2, min(hmm-h0,0)+hx2+hy2);
+ dmin = max(m1,m2) << 4;
+ /*
+ * if monotonicity would set slope = 0 then don't change hc.
+ * note dmax>=0, dmin<=0.
+ */
+ if (dmin < dmax) {
+ diff = max( min(diff, dmax), dmin);
+ /*
+ * Compute change in slope limited to range +/- smax.
+ * Careful with rounding negative numbers when using
+ * shift for divide by 64.
+ */
+ s = diff-(a[s10+1]<<6);
+ s = (s>=0) ? (s>>6) : ((s+63)>>6) ;
+ s = max( min(s, smax), -smax);
+ a[s10+1] = a[s10+1]+s;
+ }
+ s00 += 2;
+ s10 += 2;
+ }
+ }
+}
+/* ############################################################################ */
+static void
+hsmooth64(LONGLONG a[], int nxtop, int nytop, int ny, int scale)
+/*
+LONGLONG a[]; array of H-transform coefficients
+int nxtop,nytop; size of coefficient block to use
+int ny; actual 1st dimension of array
+int scale; truncation scale factor that was used
+*/
+{
+int i, j;
+int ny2, s10, s00;
+LONGLONG hm, h0, hp, hmm, hpm, hmp, hpp, hx2, hy2, diff, dmax, dmin, s, smax, m1, m2;
+
+ /*
+ * Maximum change in coefficients is determined by scale factor.
+ * Since we rounded during division (see digitize.c), the biggest
+ * permitted change is scale/2.
+ */
+ smax = (scale >> 1);
+ if (smax <= 0) return;
+ ny2 = ny << 1;
+ /*
+ * We're indexing a as a 2-D array with dimensions (nxtop,ny) of which
+ * only (nxtop,nytop) are used. The coefficients on the edge of the
+ * array are not adjusted (which is why the loops below start at 2
+ * instead of 0 and end at nxtop-2 instead of nxtop.)
+ */
+ /*
+ * Adjust x difference hx
+ */
+ for (i = 2; i<nxtop-2; i += 2) {
+ s00 = ny*i; /* s00 is index of a[i,j] */
+ s10 = s00+ny; /* s10 is index of a[i+1,j] */
+ for (j = 0; j<nytop; j += 2) {
+ /*
+ * hp is h0 (mean value) in next x zone, hm is h0 in previous x zone
+ */
+ hm = a[s00-ny2];
+ h0 = a[s00];
+ hp = a[s00+ny2];
+ /*
+ * diff = 8 * hx slope that would match h0 in neighboring zones
+ */
+ diff = hp-hm;
+ /*
+ * monotonicity constraints on diff
+ */
+ dmax = max( min( (hp-h0), (h0-hm) ), 0 ) << 2;
+ dmin = min( max( (hp-h0), (h0-hm) ), 0 ) << 2;
+ /*
+ * if monotonicity would set slope = 0 then don't change hx.
+ * note dmax>=0, dmin<=0.
+ */
+ if (dmin < dmax) {
+ diff = max( min(diff, dmax), dmin);
+ /*
+ * Compute change in slope limited to range +/- smax.
+ * Careful with rounding negative numbers when using
+ * shift for divide by 8.
+ */
+ s = diff-(a[s10]<<3);
+ s = (s>=0) ? (s>>3) : ((s+7)>>3) ;
+ s = max( min(s, smax), -smax);
+ a[s10] = a[s10]+s;
+ }
+ s00 += 2;
+ s10 += 2;
+ }
+ }
+ /*
+ * Adjust y difference hy
+ */
+ for (i = 0; i<nxtop; i += 2) {
+ s00 = ny*i+2;
+ s10 = s00+ny;
+ for (j = 2; j<nytop-2; j += 2) {
+ hm = a[s00-2];
+ h0 = a[s00];
+ hp = a[s00+2];
+ diff = hp-hm;
+ dmax = max( min( (hp-h0), (h0-hm) ), 0 ) << 2;
+ dmin = min( max( (hp-h0), (h0-hm) ), 0 ) << 2;
+ if (dmin < dmax) {
+ diff = max( min(diff, dmax), dmin);
+ s = diff-(a[s00+1]<<3);
+ s = (s>=0) ? (s>>3) : ((s+7)>>3) ;
+ s = max( min(s, smax), -smax);
+ a[s00+1] = a[s00+1]+s;
+ }
+ s00 += 2;
+ s10 += 2;
+ }
+ }
+ /*
+ * Adjust curvature difference hc
+ */
+ for (i = 2; i<nxtop-2; i += 2) {
+ s00 = ny*i+2;
+ s10 = s00+ny;
+ for (j = 2; j<nytop-2; j += 2) {
+ /*
+ * ------------------ y
+ * | hmp | | hpp | |
+ * ------------------ |
+ * | | h0 | | |
+ * ------------------ -------x
+ * | hmm | | hpm |
+ * ------------------
+ */
+ hmm = a[s00-ny2-2];
+ hpm = a[s00+ny2-2];
+ hmp = a[s00-ny2+2];
+ hpp = a[s00+ny2+2];
+ h0 = a[s00];
+ /*
+ * diff = 64 * hc value that would match h0 in neighboring zones
+ */
+ diff = hpp + hmm - hmp - hpm;
+ /*
+ * 2 times x,y slopes in this zone
+ */
+ hx2 = a[s10 ]<<1;
+ hy2 = a[s00+1]<<1;
+ /*
+ * monotonicity constraints on diff
+ */
+ m1 = min(max(hpp-h0,0)-hx2-hy2, max(h0-hpm,0)+hx2-hy2);
+ m2 = min(max(h0-hmp,0)-hx2+hy2, max(hmm-h0,0)+hx2+hy2);
+ dmax = min(m1,m2) << 4;
+ m1 = max(min(hpp-h0,0)-hx2-hy2, min(h0-hpm,0)+hx2-hy2);
+ m2 = max(min(h0-hmp,0)-hx2+hy2, min(hmm-h0,0)+hx2+hy2);
+ dmin = max(m1,m2) << 4;
+ /*
+ * if monotonicity would set slope = 0 then don't change hc.
+ * note dmax>=0, dmin<=0.
+ */
+ if (dmin < dmax) {
+ diff = max( min(diff, dmax), dmin);
+ /*
+ * Compute change in slope limited to range +/- smax.
+ * Careful with rounding negative numbers when using
+ * shift for divide by 64.
+ */
+ s = diff-(a[s10+1]<<6);
+ s = (s>=0) ? (s>>6) : ((s+63)>>6) ;
+ s = max( min(s, smax), -smax);
+ a[s10+1] = a[s10+1]+s;
+ }
+ s00 += 2;
+ s10 += 2;
+ }
+ }
+}
+
+
+/* ############################################################################ */
+/* ############################################################################ */
+/* Copyright (c) 1993 Association of Universities for Research
+ * in Astronomy. All rights reserved. Produced under National
+ * Aeronautics and Space Administration Contract No. NAS5-26555.
+ */
+/* undigitize.c undigitize H-transform
+ *
+ * Programmer: R. White Date: 9 May 1991
+ */
+
+/* ############################################################################ */
+static void
+undigitize(int a[], int nx, int ny, int scale)
+{
+int *p;
+
+ /*
+ * multiply by scale
+ */
+ if (scale <= 1) return;
+ for (p=a; p <= &a[nx*ny-1]; p++) *p = (*p)*scale;
+}
+/* ############################################################################ */
+static void
+undigitize64(LONGLONG a[], int nx, int ny, int scale)
+{
+LONGLONG *p, scale64;
+
+ /*
+ * multiply by scale
+ */
+ if (scale <= 1) return;
+ scale64 = (LONGLONG) scale; /* use a 64-bit int for efficiency in the big loop */
+
+ for (p=a; p <= &a[nx*ny-1]; p++) *p = (*p)*scale64;
+}
+
+/* ############################################################################ */
+/* ############################################################################ */
+/* Copyright (c) 1993 Association of Universities for Research
+ * in Astronomy. All rights reserved. Produced under National
+ * Aeronautics and Space Administration Contract No. NAS5-26555.
+ */
+/* decode.c read codes from infile and construct array
+ *
+ * Programmer: R. White Date: 2 February 1994
+ */
+
+
+static char code_magic[2] = { (char)0xDD, (char)0x99 };
+
+/* ############################################################################ */
+static int decode(unsigned char *infile, int *a, int *nx, int *ny, int *scale)
+/*
+char *infile; input file
+int *a; address of output array [nx][ny]
+int *nx,*ny; size of output array
+int *scale; scale factor for digitization
+*/
+{
+LONGLONG sumall;
+int nel, stat;
+unsigned char nbitplanes[3];
+char tmagic[2];
+
+ /* initialize the byte read position to the beginning of the array */;
+ nextchar = 0;
+
+ /*
+ * File starts either with special 2-byte magic code or with
+ * FITS keyword "SIMPLE ="
+ */
+ qread(infile, tmagic, sizeof(tmagic));
+ /*
+ * check for correct magic code value
+ */
+ if (memcmp(tmagic,code_magic,sizeof(code_magic)) != 0) {
+ ffpmsg("bad file format");
+ return(DATA_DECOMPRESSION_ERR);
+ }
+ *nx =readint(infile); /* x size of image */
+ *ny =readint(infile); /* y size of image */
+ *scale=readint(infile); /* scale factor for digitization */
+
+ nel = (*nx) * (*ny);
+
+ /* sum of all pixels */
+ sumall=readlonglong(infile);
+ /* # bits in quadrants */
+
+ qread(infile, (char *) nbitplanes, sizeof(nbitplanes));
+
+ stat = dodecode(infile, a, *nx, *ny, nbitplanes);
+ /*
+ * put sum of all pixels back into pixel 0
+ */
+ a[0] = (int) sumall;
+ return(stat);
+}
+/* ############################################################################ */
+static int decode64(unsigned char *infile, LONGLONG *a, int *nx, int *ny, int *scale)
+/*
+char *infile; input file
+LONGLONG *a; address of output array [nx][ny]
+int *nx,*ny; size of output array
+int *scale; scale factor for digitization
+*/
+{
+int nel, stat;
+LONGLONG sumall;
+unsigned char nbitplanes[3];
+char tmagic[2];
+
+ /* initialize the byte read position to the beginning of the array */;
+ nextchar = 0;
+
+ /*
+ * File starts either with special 2-byte magic code or with
+ * FITS keyword "SIMPLE ="
+ */
+ qread(infile, tmagic, sizeof(tmagic));
+ /*
+ * check for correct magic code value
+ */
+ if (memcmp(tmagic,code_magic,sizeof(code_magic)) != 0) {
+ ffpmsg("bad file format");
+ return(DATA_DECOMPRESSION_ERR);
+ }
+ *nx =readint(infile); /* x size of image */
+ *ny =readint(infile); /* y size of image */
+ *scale=readint(infile); /* scale factor for digitization */
+
+ nel = (*nx) * (*ny);
+
+ /* sum of all pixels */
+ sumall=readlonglong(infile);
+ /* # bits in quadrants */
+
+ qread(infile, (char *) nbitplanes, sizeof(nbitplanes));
+
+ stat = dodecode64(infile, a, *nx, *ny, nbitplanes);
+ /*
+ * put sum of all pixels back into pixel 0
+ */
+ a[0] = sumall;
+
+ return(stat);
+}
+
+
+/* ############################################################################ */
+/* ############################################################################ */
+/* Copyright (c) 1993 Association of Universities for Research
+ * in Astronomy. All rights reserved. Produced under National
+ * Aeronautics and Space Administration Contract No. NAS5-26555.
+ */
+/* dodecode.c Decode stream of characters on infile and return array
+ *
+ * This version encodes the different quadrants separately
+ *
+ * Programmer: R. White Date: 9 May 1991
+ */
+
+/* ############################################################################ */
+static int
+dodecode(unsigned char *infile, int a[], int nx, int ny, unsigned char nbitplanes[3])
+
+/* int a[];
+ int nx,ny; Array dimensions are [nx][ny]
+ unsigned char nbitplanes[3]; Number of bit planes in quadrants
+*/
+{
+int i, nel, nx2, ny2, stat;
+
+ nel = nx*ny;
+ nx2 = (nx+1)/2;
+ ny2 = (ny+1)/2;
+
+ /*
+ * initialize a to zero
+ */
+ for (i=0; i<nel; i++) a[i] = 0;
+ /*
+ * Initialize bit input
+ */
+ start_inputing_bits();
+ /*
+ * read bit planes for each quadrant
+ */
+ stat = qtree_decode(infile, &a[0], ny, nx2, ny2, nbitplanes[0]);
+ if (stat) return(stat);
+
+ stat = qtree_decode(infile, &a[ny2], ny, nx2, ny/2, nbitplanes[1]);
+ if (stat) return(stat);
+
+ stat = qtree_decode(infile, &a[ny*nx2], ny, nx/2, ny2, nbitplanes[1]);
+ if (stat) return(stat);
+
+ stat = qtree_decode(infile, &a[ny*nx2+ny2], ny, nx/2, ny/2, nbitplanes[2]);
+ if (stat) return(stat);
+
+ /*
+ * make sure there is an EOF symbol (nybble=0) at end
+ */
+ if (input_nybble(infile) != 0) {
+ ffpmsg("dodecode: bad bit plane values");
+ return(DATA_DECOMPRESSION_ERR);
+ }
+ /*
+ * now get the sign bits
+ * Re-initialize bit input
+ */
+ start_inputing_bits();
+ for (i=0; i<nel; i++) {
+ if (a[i]) {
+ /* tried putting the input_bit code in-line here, instead of */
+ /* calling the function, but it made no difference in the speed */
+ if (input_bit(infile)) a[i] = -a[i];
+ }
+ }
+ return(0);
+}
+/* ############################################################################ */
+static int
+dodecode64(unsigned char *infile, LONGLONG a[], int nx, int ny, unsigned char nbitplanes[3])
+
+/* LONGLONG a[];
+ int nx,ny; Array dimensions are [nx][ny]
+ unsigned char nbitplanes[3]; Number of bit planes in quadrants
+*/
+{
+int i, nel, nx2, ny2, stat;
+
+ nel = nx*ny;
+ nx2 = (nx+1)/2;
+ ny2 = (ny+1)/2;
+
+ /*
+ * initialize a to zero
+ */
+ for (i=0; i<nel; i++) a[i] = 0;
+ /*
+ * Initialize bit input
+ */
+ start_inputing_bits();
+ /*
+ * read bit planes for each quadrant
+ */
+ stat = qtree_decode64(infile, &a[0], ny, nx2, ny2, nbitplanes[0]);
+ if (stat) return(stat);
+
+ stat = qtree_decode64(infile, &a[ny2], ny, nx2, ny/2, nbitplanes[1]);
+ if (stat) return(stat);
+
+ stat = qtree_decode64(infile, &a[ny*nx2], ny, nx/2, ny2, nbitplanes[1]);
+ if (stat) return(stat);
+
+ stat = qtree_decode64(infile, &a[ny*nx2+ny2], ny, nx/2, ny/2, nbitplanes[2]);
+ if (stat) return(stat);
+
+ /*
+ * make sure there is an EOF symbol (nybble=0) at end
+ */
+ if (input_nybble(infile) != 0) {
+ ffpmsg("dodecode64: bad bit plane values");
+ return(DATA_DECOMPRESSION_ERR);
+ }
+ /*
+ * now get the sign bits
+ * Re-initialize bit input
+ */
+ start_inputing_bits();
+ for (i=0; i<nel; i++) {
+ if (a[i]) {
+ if (input_bit(infile) != 0) a[i] = -a[i];
+ }
+ }
+ return(0);
+}
+
+/* ############################################################################ */
+/* ############################################################################ */
+/* Copyright (c) 1993 Association of Universities for Research
+ * in Astronomy. All rights reserved. Produced under National
+ * Aeronautics and Space Administration Contract No. NAS5-26555.
+ */
+/* qtree_decode.c Read stream of codes from infile and construct bit planes
+ * in quadrant of 2-D array using binary quadtree coding
+ *
+ * Programmer: R. White Date: 7 May 1991
+ */
+
+/* ############################################################################ */
+static int
+qtree_decode(unsigned char *infile, int a[], int n, int nqx, int nqy, int nbitplanes)
+
+/*
+char *infile;
+int a[]; a is 2-D array with dimensions (n,n)
+int n; length of full row in a
+int nqx; partial length of row to decode
+int nqy; partial length of column (<=n)
+int nbitplanes; number of bitplanes to decode
+*/
+{
+int log2n, k, bit, b, nqmax;
+int nx,ny,nfx,nfy,c;
+int nqx2, nqy2;
+unsigned char *scratch;
+
+ /*
+ * log2n is log2 of max(nqx,nqy) rounded up to next power of 2
+ */
+ nqmax = (nqx>nqy) ? nqx : nqy;
+ log2n = (int) (log((float) nqmax)/log(2.0)+0.5);
+ if (nqmax > (1<<log2n)) {
+ log2n += 1;
+ }
+ /*
+ * allocate scratch array for working space
+ */
+ nqx2=(nqx+1)/2;
+ nqy2=(nqy+1)/2;
+ scratch = (unsigned char *) malloc(nqx2*nqy2);
+ if (scratch == (unsigned char *) NULL) {
+ ffpmsg("qtree_decode: insufficient memory");
+ return(DATA_DECOMPRESSION_ERR);
+ }
+ /*
+ * now decode each bit plane, starting at the top
+ * A is assumed to be initialized to zero
+ */
+ for (bit = nbitplanes-1; bit >= 0; bit--) {
+ /*
+ * Was bitplane was quadtree-coded or written directly?
+ */
+ b = input_nybble(infile);
+
+ if(b == 0) {
+ /*
+ * bit map was written directly
+ */
+ read_bdirect(infile,a,n,nqx,nqy,scratch,bit);
+ } else if (b != 0xf) {
+ ffpmsg("qtree_decode: bad format code");
+ return(DATA_DECOMPRESSION_ERR);
+ } else {
+ /*
+ * bitmap was quadtree-coded, do log2n expansions
+ *
+ * read first code
+ */
+ scratch[0] = input_huffman(infile);
+ /*
+ * now do log2n expansions, reading codes from file as necessary
+ */
+ nx = 1;
+ ny = 1;
+ nfx = nqx;
+ nfy = nqy;
+ c = 1<<log2n;
+ for (k = 1; k<log2n; k++) {
+ /*
+ * this somewhat cryptic code generates the sequence
+ * n[k-1] = (n[k]+1)/2 where n[log2n]=nqx or nqy
+ */
+ c = c>>1;
+ nx = nx<<1;
+ ny = ny<<1;
+ if (nfx <= c) { nx -= 1; } else { nfx -= c; }
+ if (nfy <= c) { ny -= 1; } else { nfy -= c; }
+ qtree_expand(infile,scratch,nx,ny,scratch);
+ }
+ /*
+ * now copy last set of 4-bit codes to bitplane bit of array a
+ */
+ qtree_bitins(scratch,nqx,nqy,a,n,bit);
+ }
+ }
+ free(scratch);
+ return(0);
+}
+/* ############################################################################ */
+static int
+qtree_decode64(unsigned char *infile, LONGLONG a[], int n, int nqx, int nqy, int nbitplanes)
+
+/*
+char *infile;
+LONGLONG a[]; a is 2-D array with dimensions (n,n)
+int n; length of full row in a
+int nqx; partial length of row to decode
+int nqy; partial length of column (<=n)
+int nbitplanes; number of bitplanes to decode
+*/
+{
+int log2n, k, bit, b, nqmax;
+int nx,ny,nfx,nfy,c;
+int nqx2, nqy2;
+unsigned char *scratch;
+
+ /*
+ * log2n is log2 of max(nqx,nqy) rounded up to next power of 2
+ */
+ nqmax = (nqx>nqy) ? nqx : nqy;
+ log2n = (int) (log((float) nqmax)/log(2.0)+0.5);
+ if (nqmax > (1<<log2n)) {
+ log2n += 1;
+ }
+ /*
+ * allocate scratch array for working space
+ */
+ nqx2=(nqx+1)/2;
+ nqy2=(nqy+1)/2;
+ scratch = (unsigned char *) malloc(nqx2*nqy2);
+ if (scratch == (unsigned char *) NULL) {
+ ffpmsg("qtree_decode64: insufficient memory");
+ return(DATA_DECOMPRESSION_ERR);
+ }
+ /*
+ * now decode each bit plane, starting at the top
+ * A is assumed to be initialized to zero
+ */
+ for (bit = nbitplanes-1; bit >= 0; bit--) {
+ /*
+ * Was bitplane was quadtree-coded or written directly?
+ */
+ b = input_nybble(infile);
+
+ if(b == 0) {
+ /*
+ * bit map was written directly
+ */
+ read_bdirect64(infile,a,n,nqx,nqy,scratch,bit);
+ } else if (b != 0xf) {
+ ffpmsg("qtree_decode64: bad format code");
+ return(DATA_DECOMPRESSION_ERR);
+ } else {
+ /*
+ * bitmap was quadtree-coded, do log2n expansions
+ *
+ * read first code
+ */
+ scratch[0] = input_huffman(infile);
+ /*
+ * now do log2n expansions, reading codes from file as necessary
+ */
+ nx = 1;
+ ny = 1;
+ nfx = nqx;
+ nfy = nqy;
+ c = 1<<log2n;
+ for (k = 1; k<log2n; k++) {
+ /*
+ * this somewhat cryptic code generates the sequence
+ * n[k-1] = (n[k]+1)/2 where n[log2n]=nqx or nqy
+ */
+ c = c>>1;
+ nx = nx<<1;
+ ny = ny<<1;
+ if (nfx <= c) { nx -= 1; } else { nfx -= c; }
+ if (nfy <= c) { ny -= 1; } else { nfy -= c; }
+ qtree_expand(infile,scratch,nx,ny,scratch);
+ }
+ /*
+ * now copy last set of 4-bit codes to bitplane bit of array a
+ */
+ qtree_bitins64(scratch,nqx,nqy,a,n,bit);
+ }
+ }
+ free(scratch);
+ return(0);
+}
+
+
+/* ############################################################################ */
+/*
+ * do one quadtree expansion step on array a[(nqx+1)/2,(nqy+1)/2]
+ * results put into b[nqx,nqy] (which may be the same as a)
+ */
+static void
+qtree_expand(unsigned char *infile, unsigned char a[], int nx, int ny, unsigned char b[])
+{
+int i;
+
+ /*
+ * first copy a to b, expanding each 4-bit value
+ */
+ qtree_copy(a,nx,ny,b,ny);
+ /*
+ * now read new 4-bit values into b for each non-zero element
+ */
+ for (i = nx*ny-1; i >= 0; i--) {
+ if (b[i]) b[i] = input_huffman(infile);
+ }
+}
+
+/* ############################################################################ */
+/*
+ * copy 4-bit values from a[(nx+1)/2,(ny+1)/2] to b[nx,ny], expanding
+ * each value to 2x2 pixels
+ * a,b may be same array
+ */
+static void
+qtree_copy(unsigned char a[], int nx, int ny, unsigned char b[], int n)
+/* int n; declared y dimension of b */
+{
+int i, j, k, nx2, ny2;
+int s00, s10;
+
+ /*
+ * first copy 4-bit values to b
+ * start at end in case a,b are same array
+ */
+ nx2 = (nx+1)/2;
+ ny2 = (ny+1)/2;
+ k = ny2*(nx2-1)+ny2-1; /* k is index of a[i,j] */
+ for (i = nx2-1; i >= 0; i--) {
+ s00 = 2*(n*i+ny2-1); /* s00 is index of b[2*i,2*j] */
+ for (j = ny2-1; j >= 0; j--) {
+ b[s00] = a[k];
+ k -= 1;
+ s00 -= 2;
+ }
+ }
+ /*
+ * now expand each 2x2 block
+ */
+ for (i = 0; i<nx-1; i += 2) {
+
+ /* Note:
+ Unlike the case in qtree_bitins, this code runs faster on a 32-bit linux
+ machine using the s10 intermediate variable, rather that using s00+n.
+ Go figure!
+ */
+ s00 = n*i; /* s00 is index of b[i,j] */
+ s10 = s00+n; /* s10 is index of b[i+1,j] */
+
+ for (j = 0; j<ny-1; j += 2) {
+
+ switch (b[s00]) {
+ case(0):
+ b[s10+1] = 0;
+ b[s10 ] = 0;
+ b[s00+1] = 0;
+ b[s00 ] = 0;
+
+ break;
+ case(1):
+ b[s10+1] = 1;
+ b[s10 ] = 0;
+ b[s00+1] = 0;
+ b[s00 ] = 0;
+
+ break;
+ case(2):
+ b[s10+1] = 0;
+ b[s10 ] = 1;
+ b[s00+1] = 0;
+ b[s00 ] = 0;
+
+ break;
+ case(3):
+ b[s10+1] = 1;
+ b[s10 ] = 1;
+ b[s00+1] = 0;
+ b[s00 ] = 0;
+
+ break;
+ case(4):
+ b[s10+1] = 0;
+ b[s10 ] = 0;
+ b[s00+1] = 1;
+ b[s00 ] = 0;
+
+ break;
+ case(5):
+ b[s10+1] = 1;
+ b[s10 ] = 0;
+ b[s00+1] = 1;
+ b[s00 ] = 0;
+
+ break;
+ case(6):
+ b[s10+1] = 0;
+ b[s10 ] = 1;
+ b[s00+1] = 1;
+ b[s00 ] = 0;
+
+ break;
+ case(7):
+ b[s10+1] = 1;
+ b[s10 ] = 1;
+ b[s00+1] = 1;
+ b[s00 ] = 0;
+
+ break;
+ case(8):
+ b[s10+1] = 0;
+ b[s10 ] = 0;
+ b[s00+1] = 0;
+ b[s00 ] = 1;
+
+ break;
+ case(9):
+ b[s10+1] = 1;
+ b[s10 ] = 0;
+ b[s00+1] = 0;
+ b[s00 ] = 1;
+ break;
+ case(10):
+ b[s10+1] = 0;
+ b[s10 ] = 1;
+ b[s00+1] = 0;
+ b[s00 ] = 1;
+
+ break;
+ case(11):
+ b[s10+1] = 1;
+ b[s10 ] = 1;
+ b[s00+1] = 0;
+ b[s00 ] = 1;
+
+ break;
+ case(12):
+ b[s10+1] = 0;
+ b[s10 ] = 0;
+ b[s00+1] = 1;
+ b[s00 ] = 1;
+
+ break;
+ case(13):
+ b[s10+1] = 1;
+ b[s10 ] = 0;
+ b[s00+1] = 1;
+ b[s00 ] = 1;
+
+ break;
+ case(14):
+ b[s10+1] = 0;
+ b[s10 ] = 1;
+ b[s00+1] = 1;
+ b[s00 ] = 1;
+
+ break;
+ case(15):
+ b[s10+1] = 1;
+ b[s10 ] = 1;
+ b[s00+1] = 1;
+ b[s00 ] = 1;
+
+ break;
+ }
+/*
+ b[s10+1] = b[s00] & 1;
+ b[s10 ] = (b[s00]>>1) & 1;
+ b[s00+1] = (b[s00]>>2) & 1;
+ b[s00 ] = (b[s00]>>3) & 1;
+*/
+
+ s00 += 2;
+ s10 += 2;
+ }
+
+ if (j < ny) {
+ /*
+ * row size is odd, do last element in row
+ * s00+1, s10+1 are off edge
+ */
+ /* not worth converting this to use 16 case statements */
+ b[s10 ] = (b[s00]>>1) & 1;
+ b[s00 ] = (b[s00]>>3) & 1;
+ }
+ }
+ if (i < nx) {
+ /*
+ * column size is odd, do last row
+ * s10, s10+1 are off edge
+ */
+ s00 = n*i;
+ for (j = 0; j<ny-1; j += 2) {
+ /* not worth converting this to use 16 case statements */
+ b[s00+1] = (b[s00]>>2) & 1;
+ b[s00 ] = (b[s00]>>3) & 1;
+ s00 += 2;
+ }
+ if (j < ny) {
+ /*
+ * both row and column size are odd, do corner element
+ * s00+1, s10, s10+1 are off edge
+ */
+ /* not worth converting this to use 16 case statements */
+ b[s00 ] = (b[s00]>>3) & 1;
+ }
+ }
+}
+
+/* ############################################################################ */
+/*
+ * Copy 4-bit values from a[(nx+1)/2,(ny+1)/2] to b[nx,ny], expanding
+ * each value to 2x2 pixels and inserting into bitplane BIT of B.
+ * A,B may NOT be same array (it wouldn't make sense to be inserting
+ * bits into the same array anyway.)
+ */
+static void
+qtree_bitins(unsigned char a[], int nx, int ny, int b[], int n, int bit)
+/*
+ int n; declared y dimension of b
+*/
+{
+int i, j, k;
+int s00;
+int plane_val;
+
+ plane_val = 1 << bit;
+
+ /*
+ * expand each 2x2 block
+ */
+ k = 0; /* k is index of a[i/2,j/2] */
+ for (i = 0; i<nx-1; i += 2) {
+ s00 = n*i; /* s00 is index of b[i,j] */
+
+ /* Note:
+ this code appears to run very slightly faster on a 32-bit linux
+ machine using s00+n rather than the s10 intermediate variable
+ */
+ /* s10 = s00+n; */ /* s10 is index of b[i+1,j] */
+ for (j = 0; j<ny-1; j += 2) {
+
+ switch (a[k]) {
+ case(0):
+ break;
+ case(1):
+ b[s00+n+1] |= plane_val;
+ break;
+ case(2):
+ b[s00+n ] |= plane_val;
+ break;
+ case(3):
+ b[s00+n+1] |= plane_val;
+ b[s00+n ] |= plane_val;
+ break;
+ case(4):
+ b[s00+1] |= plane_val;
+ break;
+ case(5):
+ b[s00+n+1] |= plane_val;
+ b[s00+1] |= plane_val;
+ break;
+ case(6):
+ b[s00+n ] |= plane_val;
+ b[s00+1] |= plane_val;
+ break;
+ case(7):
+ b[s00+n+1] |= plane_val;
+ b[s00+n ] |= plane_val;
+ b[s00+1] |= plane_val;
+ break;
+ case(8):
+ b[s00 ] |= plane_val;
+ break;
+ case(9):
+ b[s00+n+1] |= plane_val;
+ b[s00 ] |= plane_val;
+ break;
+ case(10):
+ b[s00+n ] |= plane_val;
+ b[s00 ] |= plane_val;
+ break;
+ case(11):
+ b[s00+n+1] |= plane_val;
+ b[s00+n ] |= plane_val;
+ b[s00 ] |= plane_val;
+ break;
+ case(12):
+ b[s00+1] |= plane_val;
+ b[s00 ] |= plane_val;
+ break;
+ case(13):
+ b[s00+n+1] |= plane_val;
+ b[s00+1] |= plane_val;
+ b[s00 ] |= plane_val;
+ break;
+ case(14):
+ b[s00+n ] |= plane_val;
+ b[s00+1] |= plane_val;
+ b[s00 ] |= plane_val;
+ break;
+ case(15):
+ b[s00+n+1] |= plane_val;
+ b[s00+n ] |= plane_val;
+ b[s00+1] |= plane_val;
+ b[s00 ] |= plane_val;
+ break;
+ }
+
+/*
+ b[s10+1] |= ( a[k] & 1) << bit;
+ b[s10 ] |= ((a[k]>>1) & 1) << bit;
+ b[s00+1] |= ((a[k]>>2) & 1) << bit;
+ b[s00 ] |= ((a[k]>>3) & 1) << bit;
+*/
+ s00 += 2;
+/* s10 += 2; */
+ k += 1;
+ }
+ if (j < ny) {
+ /*
+ * row size is odd, do last element in row
+ * s00+1, s10+1 are off edge
+ */
+
+ switch (a[k]) {
+ case(0):
+ break;
+ case(1):
+ break;
+ case(2):
+ b[s00+n ] |= plane_val;
+ break;
+ case(3):
+ b[s00+n ] |= plane_val;
+ break;
+ case(4):
+ break;
+ case(5):
+ break;
+ case(6):
+ b[s00+n ] |= plane_val;
+ break;
+ case(7):
+ b[s00+n ] |= plane_val;
+ break;
+ case(8):
+ b[s00 ] |= plane_val;
+ break;
+ case(9):
+ b[s00 ] |= plane_val;
+ break;
+ case(10):
+ b[s00+n ] |= plane_val;
+ b[s00 ] |= plane_val;
+ break;
+ case(11):
+ b[s00+n ] |= plane_val;
+ b[s00 ] |= plane_val;
+ break;
+ case(12):
+ b[s00 ] |= plane_val;
+ break;
+ case(13):
+ b[s00 ] |= plane_val;
+ break;
+ case(14):
+ b[s00+n ] |= plane_val;
+ b[s00 ] |= plane_val;
+ break;
+ case(15):
+ b[s00+n ] |= plane_val;
+ b[s00 ] |= plane_val;
+ break;
+ }
+
+/*
+ b[s10 ] |= ((a[k]>>1) & 1) << bit;
+ b[s00 ] |= ((a[k]>>3) & 1) << bit;
+*/
+ k += 1;
+ }
+ }
+ if (i < nx) {
+ /*
+ * column size is odd, do last row
+ * s10, s10+1 are off edge
+ */
+ s00 = n*i;
+ for (j = 0; j<ny-1; j += 2) {
+
+ switch (a[k]) {
+ case(0):
+ break;
+ case(1):
+ break;
+ case(2):
+ break;
+ case(3):
+ break;
+ case(4):
+ b[s00+1] |= plane_val;
+ break;
+ case(5):
+ b[s00+1] |= plane_val;
+ break;
+ case(6):
+ b[s00+1] |= plane_val;
+ break;
+ case(7):
+ b[s00+1] |= plane_val;
+ break;
+ case(8):
+ b[s00 ] |= plane_val;
+ break;
+ case(9):
+ b[s00 ] |= plane_val;
+ break;
+ case(10):
+ b[s00 ] |= plane_val;
+ break;
+ case(11):
+ b[s00 ] |= plane_val;
+ break;
+ case(12):
+ b[s00+1] |= plane_val;
+ b[s00 ] |= plane_val;
+ break;
+ case(13):
+ b[s00+1] |= plane_val;
+ b[s00 ] |= plane_val;
+ break;
+ case(14):
+ b[s00+1] |= plane_val;
+ b[s00 ] |= plane_val;
+ break;
+ case(15):
+ b[s00+1] |= plane_val;
+ b[s00 ] |= plane_val;
+ break;
+ }
+
+/*
+ b[s00+1] |= ((a[k]>>2) & 1) << bit;
+ b[s00 ] |= ((a[k]>>3) & 1) << bit;
+*/
+
+ s00 += 2;
+ k += 1;
+ }
+ if (j < ny) {
+ /*
+ * both row and column size are odd, do corner element
+ * s00+1, s10, s10+1 are off edge
+ */
+
+ switch (a[k]) {
+ case(0):
+ break;
+ case(1):
+ break;
+ case(2):
+ break;
+ case(3):
+ break;
+ case(4):
+ break;
+ case(5):
+ break;
+ case(6):
+ break;
+ case(7):
+ break;
+ case(8):
+ b[s00 ] |= plane_val;
+ break;
+ case(9):
+ b[s00 ] |= plane_val;
+ break;
+ case(10):
+ b[s00 ] |= plane_val;
+ break;
+ case(11):
+ b[s00 ] |= plane_val;
+ break;
+ case(12):
+ b[s00 ] |= plane_val;
+ break;
+ case(13):
+ b[s00 ] |= plane_val;
+ break;
+ case(14):
+ b[s00 ] |= plane_val;
+ break;
+ case(15):
+ b[s00 ] |= plane_val;
+ break;
+ }
+
+/*
+ b[s00 ] |= ((a[k]>>3) & 1) << bit;
+*/
+ k += 1;
+ }
+ }
+}
+/* ############################################################################ */
+/*
+ * Copy 4-bit values from a[(nx+1)/2,(ny+1)/2] to b[nx,ny], expanding
+ * each value to 2x2 pixels and inserting into bitplane BIT of B.
+ * A,B may NOT be same array (it wouldn't make sense to be inserting
+ * bits into the same array anyway.)
+ */
+static void
+qtree_bitins64(unsigned char a[], int nx, int ny, LONGLONG b[], int n, int bit)
+/*
+ int n; declared y dimension of b
+*/
+{
+int i, j, k;
+int s00;
+int plane_val;
+
+ plane_val = 1 << bit;
+
+ /*
+ * expand each 2x2 block
+ */
+ k = 0; /* k is index of a[i/2,j/2] */
+ for (i = 0; i<nx-1; i += 2) {
+ s00 = n*i; /* s00 is index of b[i,j] */
+
+ /* Note:
+ this code appears to run very slightly faster on a 32-bit linux
+ machine using s00+n rather than the s10 intermediate variable
+ */
+ /* s10 = s00+n; */ /* s10 is index of b[i+1,j] */
+ for (j = 0; j<ny-1; j += 2) {
+
+ switch (a[k]) {
+ case(0):
+ break;
+ case(1):
+ b[s00+n+1] |= plane_val;
+ break;
+ case(2):
+ b[s00+n ] |= plane_val;
+ break;
+ case(3):
+ b[s00+n+1] |= plane_val;
+ b[s00+n ] |= plane_val;
+ break;
+ case(4):
+ b[s00+1] |= plane_val;
+ break;
+ case(5):
+ b[s00+n+1] |= plane_val;
+ b[s00+1] |= plane_val;
+ break;
+ case(6):
+ b[s00+n ] |= plane_val;
+ b[s00+1] |= plane_val;
+ break;
+ case(7):
+ b[s00+n+1] |= plane_val;
+ b[s00+n ] |= plane_val;
+ b[s00+1] |= plane_val;
+ break;
+ case(8):
+ b[s00 ] |= plane_val;
+ break;
+ case(9):
+ b[s00+n+1] |= plane_val;
+ b[s00 ] |= plane_val;
+ break;
+ case(10):
+ b[s00+n ] |= plane_val;
+ b[s00 ] |= plane_val;
+ break;
+ case(11):
+ b[s00+n+1] |= plane_val;
+ b[s00+n ] |= plane_val;
+ b[s00 ] |= plane_val;
+ break;
+ case(12):
+ b[s00+1] |= plane_val;
+ b[s00 ] |= plane_val;
+ break;
+ case(13):
+ b[s00+n+1] |= plane_val;
+ b[s00+1] |= plane_val;
+ b[s00 ] |= plane_val;
+ break;
+ case(14):
+ b[s00+n ] |= plane_val;
+ b[s00+1] |= plane_val;
+ b[s00 ] |= plane_val;
+ break;
+ case(15):
+ b[s00+n+1] |= plane_val;
+ b[s00+n ] |= plane_val;
+ b[s00+1] |= plane_val;
+ b[s00 ] |= plane_val;
+ break;
+ }
+
+/*
+ b[s10+1] |= ((LONGLONG) ( a[k] & 1)) << bit;
+ b[s10 ] |= ((((LONGLONG)a[k])>>1) & 1) << bit;
+ b[s00+1] |= ((((LONGLONG)a[k])>>2) & 1) << bit;
+ b[s00 ] |= ((((LONGLONG)a[k])>>3) & 1) << bit;
+*/
+ s00 += 2;
+/* s10 += 2; */
+ k += 1;
+ }
+ if (j < ny) {
+ /*
+ * row size is odd, do last element in row
+ * s00+1, s10+1 are off edge
+ */
+
+ switch (a[k]) {
+ case(0):
+ break;
+ case(1):
+ break;
+ case(2):
+ b[s00+n ] |= plane_val;
+ break;
+ case(3):
+ b[s00+n ] |= plane_val;
+ break;
+ case(4):
+ break;
+ case(5):
+ break;
+ case(6):
+ b[s00+n ] |= plane_val;
+ break;
+ case(7):
+ b[s00+n ] |= plane_val;
+ break;
+ case(8):
+ b[s00 ] |= plane_val;
+ break;
+ case(9):
+ b[s00 ] |= plane_val;
+ break;
+ case(10):
+ b[s00+n ] |= plane_val;
+ b[s00 ] |= plane_val;
+ break;
+ case(11):
+ b[s00+n ] |= plane_val;
+ b[s00 ] |= plane_val;
+ break;
+ case(12):
+ b[s00 ] |= plane_val;
+ break;
+ case(13):
+ b[s00 ] |= plane_val;
+ break;
+ case(14):
+ b[s00+n ] |= plane_val;
+ b[s00 ] |= plane_val;
+ break;
+ case(15):
+ b[s00+n ] |= plane_val;
+ b[s00 ] |= plane_val;
+ break;
+ }
+/*
+ b[s10 ] |= ((((LONGLONG)a[k])>>1) & 1) << bit;
+ b[s00 ] |= ((((LONGLONG)a[k])>>3) & 1) << bit;
+*/
+ k += 1;
+ }
+ }
+ if (i < nx) {
+ /*
+ * column size is odd, do last row
+ * s10, s10+1 are off edge
+ */
+ s00 = n*i;
+ for (j = 0; j<ny-1; j += 2) {
+
+ switch (a[k]) {
+ case(0):
+ break;
+ case(1):
+ break;
+ case(2):
+ break;
+ case(3):
+ break;
+ case(4):
+ b[s00+1] |= plane_val;
+ break;
+ case(5):
+ b[s00+1] |= plane_val;
+ break;
+ case(6):
+ b[s00+1] |= plane_val;
+ break;
+ case(7):
+ b[s00+1] |= plane_val;
+ break;
+ case(8):
+ b[s00 ] |= plane_val;
+ break;
+ case(9):
+ b[s00 ] |= plane_val;
+ break;
+ case(10):
+ b[s00 ] |= plane_val;
+ break;
+ case(11):
+ b[s00 ] |= plane_val;
+ break;
+ case(12):
+ b[s00+1] |= plane_val;
+ b[s00 ] |= plane_val;
+ break;
+ case(13):
+ b[s00+1] |= plane_val;
+ b[s00 ] |= plane_val;
+ break;
+ case(14):
+ b[s00+1] |= plane_val;
+ b[s00 ] |= plane_val;
+ break;
+ case(15):
+ b[s00+1] |= plane_val;
+ b[s00 ] |= plane_val;
+ break;
+ }
+
+/*
+ b[s00+1] |= ((((LONGLONG)a[k])>>2) & 1) << bit;
+ b[s00 ] |= ((((LONGLONG)a[k])>>3) & 1) << bit;
+*/
+ s00 += 2;
+ k += 1;
+ }
+ if (j < ny) {
+ /*
+ * both row and column size are odd, do corner element
+ * s00+1, s10, s10+1 are off edge
+ */
+
+ switch (a[k]) {
+ case(0):
+ break;
+ case(1):
+ break;
+ case(2):
+ break;
+ case(3):
+ break;
+ case(4):
+ break;
+ case(5):
+ break;
+ case(6):
+ break;
+ case(7):
+ break;
+ case(8):
+ b[s00 ] |= plane_val;
+ break;
+ case(9):
+ b[s00 ] |= plane_val;
+ break;
+ case(10):
+ b[s00 ] |= plane_val;
+ break;
+ case(11):
+ b[s00 ] |= plane_val;
+ break;
+ case(12):
+ b[s00 ] |= plane_val;
+ break;
+ case(13):
+ b[s00 ] |= plane_val;
+ break;
+ case(14):
+ b[s00 ] |= plane_val;
+ break;
+ case(15):
+ b[s00 ] |= plane_val;
+ break;
+ }
+/*
+ b[s00 ] |= ((((LONGLONG)a[k])>>3) & 1) << bit;
+*/
+ k += 1;
+ }
+ }
+}
+
+/* ############################################################################ */
+static void
+read_bdirect(unsigned char *infile, int a[], int n, int nqx, int nqy, unsigned char scratch[], int bit)
+{
+
+
+ /*
+ * read bit image packed 4 pixels/nybble
+ */
+/*
+ int i;
+ for (i = 0; i < ((nqx+1)/2) * ((nqy+1)/2); i++) {
+ scratch[i] = input_nybble(infile);
+ }
+*/
+ input_nnybble(infile, ((nqx+1)/2) * ((nqy+1)/2), scratch);
+
+ /*
+ * insert in bitplane BIT of image A
+ */
+ qtree_bitins(scratch,nqx,nqy,a,n,bit);
+}
+/* ############################################################################ */
+static void
+read_bdirect64(unsigned char *infile, LONGLONG a[], int n, int nqx, int nqy, unsigned char scratch[], int bit)
+{
+
+ /*
+ * read bit image packed 4 pixels/nybble
+ */
+/*
+ int i;
+ for (i = 0; i < ((nqx+1)/2) * ((nqy+1)/2); i++) {
+ scratch[i] = input_nybble(infile);
+ }
+*/
+ input_nnybble(infile, ((nqx+1)/2) * ((nqy+1)/2), scratch);
+
+ /*
+ * insert in bitplane BIT of image A
+ */
+ qtree_bitins64(scratch,nqx,nqy,a,n,bit);
+}
+
+/* ############################################################################ */
+/*
+ * Huffman decoding for fixed codes
+ *
+ * Coded values range from 0-15
+ *
+ * Huffman code values (hex):
+ *
+ * 3e, 00, 01, 08, 02, 09, 1a, 1b,
+ * 03, 1c, 0a, 1d, 0b, 1e, 3f, 0c
+ *
+ * and number of bits in each code:
+ *
+ * 6, 3, 3, 4, 3, 4, 5, 5,
+ * 3, 5, 4, 5, 4, 5, 6, 4
+ */
+static int input_huffman(unsigned char *infile)
+{
+int c;
+
+ /*
+ * get first 3 bits to start
+ */
+ c = input_nbits(infile,3);
+ if (c < 4) {
+ /*
+ * this is all we need
+ * return 1,2,4,8 for c=0,1,2,3
+ */
+ return(1<<c);
+ }
+ /*
+ * get the next bit
+ */
+ c = input_bit(infile) | (c<<1);
+ if (c < 13) {
+ /*
+ * OK, 4 bits is enough
+ */
+ switch (c) {
+ case 8 : return(3);
+ case 9 : return(5);
+ case 10 : return(10);
+ case 11 : return(12);
+ case 12 : return(15);
+ }
+ }
+ /*
+ * get yet another bit
+ */
+ c = input_bit(infile) | (c<<1);
+ if (c < 31) {
+ /*
+ * OK, 5 bits is enough
+ */
+ switch (c) {
+ case 26 : return(6);
+ case 27 : return(7);
+ case 28 : return(9);
+ case 29 : return(11);
+ case 30 : return(13);
+ }
+ }
+ /*
+ * need the 6th bit
+ */
+ c = input_bit(infile) | (c<<1);
+ if (c == 62) {
+ return(0);
+ } else {
+ return(14);
+ }
+}
+
+/* ############################################################################ */
+/* ############################################################################ */
+/* Copyright (c) 1993 Association of Universities for Research
+ * in Astronomy. All rights reserved. Produced under National
+ * Aeronautics and Space Administration Contract No. NAS5-26555.
+ */
+/* qread.c Read binary data
+ *
+ * Programmer: R. White Date: 11 March 1991
+ */
+
+static int readint(unsigned char *infile)
+{
+int a,i;
+unsigned char b[4];
+
+ /* Read integer A one byte at a time from infile.
+ *
+ * This is portable from Vax to Sun since it eliminates the
+ * need for byte-swapping.
+ *
+ * This routine is only called to read the first 3 values
+ * in the compressed file, so it doesn't have to be
+ * super-efficient
+ */
+ for (i=0; i<4; i++) qread(infile,(char *) &b[i],1);
+ a = b[0];
+ for (i=1; i<4; i++) a = (a<<8) + b[i];
+ return(a);
+}
+
+/* ############################################################################ */
+static LONGLONG readlonglong(unsigned char *infile)
+{
+int i;
+LONGLONG a;
+unsigned char b[8];
+
+ /* Read integer A one byte at a time from infile.
+ *
+ * This is portable from Vax to Sun since it eliminates the
+ * need for byte-swapping.
+ *
+ * This routine is only called to read the first 3 values
+ * in the compressed file, so it doesn't have to be
+ * super-efficient
+ */
+ for (i=0; i<8; i++) qread(infile,(char *) &b[i],1);
+ a = b[0];
+ for (i=1; i<8; i++) a = (a<<8) + b[i];
+ return(a);
+}
+
+/* ############################################################################ */
+static void qread(unsigned char *file, char buffer[], int n)
+{
+ /*
+ * read n bytes from file into buffer
+ *
+ */
+
+ memcpy(buffer, &file[nextchar], n);
+ nextchar += n;
+}
+
+/* ############################################################################ */
+/* ############################################################################ */
+/* Copyright (c) 1993 Association of Universities for Research
+ * in Astronomy. All rights reserved. Produced under National
+ * Aeronautics and Space Administration Contract No. NAS5-26555.
+ */
+
+/* BIT INPUT ROUTINES */
+
+/* THE BIT BUFFER */
+
+static int buffer2; /* Bits waiting to be input */
+static int bits_to_go; /* Number of bits still in buffer */
+
+/* INITIALIZE BIT INPUT */
+
+/* ############################################################################ */
+static void start_inputing_bits()
+{
+ /*
+ * Buffer starts out with no bits in it
+ */
+ bits_to_go = 0;
+}
+
+/* ############################################################################ */
+/* INPUT A BIT */
+
+static int input_bit(unsigned char *infile)
+{
+ if (bits_to_go == 0) { /* Read the next byte if no */
+
+ buffer2 = infile[nextchar];
+ nextchar++;
+
+ bits_to_go = 8;
+ }
+ /*
+ * Return the next bit
+ */
+ bits_to_go -= 1;
+ return((buffer2>>bits_to_go) & 1);
+}
+
+/* ############################################################################ */
+/* INPUT N BITS (N must be <= 8) */
+
+static int input_nbits(unsigned char *infile, int n)
+{
+ /* AND mask for retreiving the right-most n bits */
+ static int mask[9] = {0, 1, 3, 7, 15, 31, 63, 127, 255};
+
+ if (bits_to_go < n) {
+ /*
+ * need another byte's worth of bits
+ */
+
+ buffer2 = (buffer2<<8) | (int) infile[nextchar];
+ nextchar++;
+ bits_to_go += 8;
+ }
+ /*
+ * now pick off the first n bits
+ */
+ bits_to_go -= n;
+
+ /* there was a slight gain in speed by replacing the following line */
+/* return( (buffer2>>bits_to_go) & ((1<<n)-1) ); */
+ return( (buffer2>>bits_to_go) & (*(mask+n)) );
+}
+/* ############################################################################ */
+/* INPUT 4 BITS */
+
+static int input_nybble(unsigned char *infile)
+{
+ if (bits_to_go < 4) {
+ /*
+ * need another byte's worth of bits
+ */
+
+ buffer2 = (buffer2<<8) | (int) infile[nextchar];
+ nextchar++;
+ bits_to_go += 8;
+ }
+ /*
+ * now pick off the first 4 bits
+ */
+ bits_to_go -= 4;
+
+ return( (buffer2>>bits_to_go) & 15 );
+}
+/* ############################################################################ */
+/* INPUT array of 4 BITS */
+
+static int input_nnybble(unsigned char *infile, int n, unsigned char array[])
+{
+ /* copy n 4-bit nybbles from infile to the lower 4 bits of array */
+
+int ii, kk, shift1, shift2;
+
+/* forcing byte alignment doesn;t help, and even makes it go slightly slower
+if (bits_to_go != 8) input_nbits(infile, bits_to_go);
+*/
+ if (n == 1) {
+ array[0] = input_nybble(infile);
+ return(0);
+ }
+
+ if (bits_to_go == 8) {
+ /*
+ already have 2 full nybbles in buffer2, so
+ backspace the infile array to reuse last char
+ */
+ nextchar--;
+ bits_to_go = 0;
+ }
+
+ /* bits_to_go now has a value in the range 0 - 7. After adding */
+ /* another byte, bits_to_go effectively will be in range 8 - 15 */
+
+ shift1 = bits_to_go + 4; /* shift1 will be in range 4 - 11 */
+ shift2 = bits_to_go; /* shift2 will be in range 0 - 7 */
+ kk = 0;
+
+ /* special case */
+ if (bits_to_go == 0)
+ {
+ for (ii = 0; ii < n/2; ii++) {
+ /*
+ * refill the buffer with next byte
+ */
+ buffer2 = (buffer2<<8) | (int) infile[nextchar];
+ nextchar++;
+ array[kk] = (int) ((buffer2>>4) & 15);
+ array[kk + 1] = (int) ((buffer2) & 15); /* no shift required */
+ kk += 2;
+ }
+ }
+ else
+ {
+ for (ii = 0; ii < n/2; ii++) {
+ /*
+ * refill the buffer with next byte
+ */
+ buffer2 = (buffer2<<8) | (int) infile[nextchar];
+ nextchar++;
+ array[kk] = (int) ((buffer2>>shift1) & 15);
+ array[kk + 1] = (int) ((buffer2>>shift2) & 15);
+ kk += 2;
+ }
+ }
+
+
+ if (ii * 2 != n) { /* have to read last odd byte */
+ array[n-1] = input_nybble(infile);
+ }
+
+ return( (buffer2>>bits_to_go) & 15 );
+}
generated by cgit v0.12 at 2024-11-18 06:18:32 (GMT)