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git-svn-id: http://svn.code.sf.net/p/netpbm/code/trunk@1 9d0c8265-081b-0410-96cb-a4ca84ce46f8

1 files changed, 231 insertions, 0 deletions

diff --git a/converter/pgm/spottopgm.c b/converter/pgm/spottopgm.c
new file mode 100644
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--- /dev/null
+++ b/converter/pgm/spottopgm.c
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+/* Spottopgm: Convert a SPOT satellite image to PGM format.
+ *
+ * Usage: spottopgm [-1|2|3] [Firstcol Firstline Lastcol Lastline] inputfile
+ *
+ * Author: Warren Toomey, 1992.
+ */
+
+#include <stdio.h>
+#include "pgm.h"
+
+/* Global variables */
+
+static FILE *spotfile;          /* The input file */
+static char linebuf[12000];        /* The line buffer */
+
+static long Firstline = 0,     /* The rectangle the user wants */
+    Lastline = 3000,   /* cut out of the image */
+    Firstcol = 0,
+    Lastcol = 0;
+static long Diff = 0;          /* Firstcol - Lastcol */
+static char *Bufptr;           /* Pointer into the input image */
+static int Color = 1;          /* Either 1, 2 or 3 */
+static int Colbool = 0;        /* 1 if color */
+
+
+/* Get_image extracts the pixel data from one line
+ * (i.e one record) in the SPOT input file. A SPOT image
+ * record has a header, data and trailer. The data lengths
+ * are fixed at 3960, 5400, 8640 or 10980 bytes.
+ *
+ * When we arrive here we have read in 12 bytes of the record.
+ * We then read in the rest of the record. We find the trailer
+ * and from that determine the number of pixels on the line.
+ *
+ * If the image is really color i.e interleaved 3 colors, we
+ * convert a line if its spectral sequence is the same as the one
+ * requested by the user (i.e 1, 2 or 3). I could create a ppm file
+ * but I couldn't be bothered with the rearranging of the data.
+ */
+static int 
+get_image(long length)
+{
+    int cnt;
+    struct Linehdr        /* Each line begins with the 12 bytes */
+    {             /* we have already, plus these 20 bytes */
+        long linenum;       /* The line number of the record */
+        short recseq;       /* The record sequence number */
+        short spectseq;     /* The spectral number of the line */
+        long linetime;      /* Time it was recorded (in ms). */
+        long leftpixmar;        /* The pixel number of the 1st pixel */
+        long rightpixmar;       /* The pixel number of the last pixel */
+    } linehdr;
+    long numpixels;       /* Number of pixels on the line */
+
+    /* Get the details of this line */
+    if (pm_readbiglong (spotfile, &linehdr.linenum) == -1
+        || pm_readbigshort (spotfile, &linehdr.recseq) == -1
+        || pm_readbigshort (spotfile, &linehdr.spectseq) == -1
+        || pm_readbiglong (spotfile, &linehdr.linetime) == -1
+        || pm_readbiglong (spotfile, &linehdr.leftpixmar) == -1
+        || pm_readbiglong (spotfile, &linehdr.rightpixmar) == -1)
+        pm_error ("EOF / read error reading line header");
+
+    /* Now read in the line data */
+    cnt = length - 20 - 88;
+    cnt = fread(linebuf, 1, cnt, spotfile);
+
+    if (!Diff)
+    {
+        cnt += 28;
+        if (fseek (spotfile, 24, 1) == EOF)
+            pm_error ("seek error");
+        if (pm_readbiglong (spotfile, &numpixels) == -1)
+            pm_error ("EOF / read error reading line ender");
+    
+        /* Determine the picture size */
+        Bufptr = &linebuf[Firstcol];
+        if (Lastcol == 0 || Lastcol > numpixels)
+            Lastcol = numpixels;
+        Diff = Lastcol - Firstcol;
+        /* Print out the header */
+        printf("P5\n%ld %ld\n255\n", Diff, Lastline - Firstline);
+        /* Inform about the image size */
+        if (Colbool) fprintf(stderr, "Color image, ");
+        fprintf(stderr, "%ld pixels wide\n", numpixels);
+    }
+
+    /* Output the line */
+    if (linehdr.linenum >= Firstline && linehdr.linenum <= Lastline
+        && linehdr.spectseq == Color)
+        fwrite(Bufptr, 1, Diff, stdout);
+    if (linehdr.linenum > Lastline) exit(0);
+
+#ifdef DEBUG
+    fprintf(stderr,
+            "Line %4d, %3d, %3d, time %4d, l/r "
+            "pixmar %4d %4d len %d pixnum %d\n",
+            linehdr.linenum, linehdr.recseq, 
+            linehdr.spectseq, linehdr.linetime,
+            linehdr.leftpixmar, linehdr.rightpixmar, length, numpixels);
+#endif
+    /* And return the amount to seek */
+    return (length - 20 - cnt);
+}
+
+
+
+/* The image header tells us if the image is in monochrome or color, and
+ * if the latter, if the input colors are interleaved. If interleaved
+ * color, lines are interleaved R, G, B, R, G, B etc. Technically, some
+ * interleaving of infra-red, visible and ultra-violet.
+ *
+ * In the description field below,
+ *  element 0 == P --> monochrome
+ *  element 0 == X --> color
+ *  element 9 == S --> sequential (i.e only one color here)
+ *  element 9 == I --> interleaved (1 or more colors)
+ */
+static int 
+get_imghdr(int length)
+{
+    struct Imghdr
+    {
+        long linewidth;
+        char dummy1[36];
+        char description[16];   /* Type of image */
+    } header;
+
+    if (pm_readbiglong (spotfile, &header.linewidth) == -1)
+        pm_error ("EOF / read error reading header");
+#ifdef DEBUG
+    if (fread (header.dummy1, 1, 36, spotfile) != 36)
+        pm_error ("EOF / read error reading header");
+#else
+    if (fseek (spotfile, 36, 1) == EOF)
+        pm_error ("seek error");
+#endif
+    if (fread (header.description, 1, 16, spotfile) != 16)
+        pm_error ("EOF / read error reading header");
+
+    /* Determine mono or color */
+    if (header.description[0] == 'X' && header.description[9] == 'S')
+        Colbool = 1;
+    else Colbool = 0;
+
+#ifdef DEBUG
+    fprintf(stderr, "Dummy str is >%s<\n", header.dummy1);
+    fprintf(stderr, "Imghdr str is >%s<, col %d\n", 
+            header.description, Colbool);
+#endif
+    /* Return the amount to fseek */
+    return (length - 56);
+}
+
+
+static void
+usage()
+{
+    fprintf(stderr,
+            "Usage: spottopgm [-1|2|3] [Firstcol Firstline Lastcol Lastline] "
+            "input_file\n");
+    exit(1);
+}
+
+int
+main(int argc, char *argv[])
+{
+    struct Record             /* A SPOT image is broken up into */
+    {                 /* records with the following fields */
+        long record;            /* The record number (1, 2, 3...) */
+        unsigned char sub1;         /* Record sub type 1 */
+        unsigned char type;         /* The record type */
+        unsigned char sub2;         /* Record sub type 2 */
+        unsigned char sub3;         /* Record sub type 3 */
+        long length;            /* Record length in bytes */
+    } arecord;
+
+    pgm_init( &argc, argv );
+   
+    switch (argc)
+    {
+    case 7:
+        Color= -(atoi(argv[1]));      /* Get the color to extract */
+        argv++;
+    case 6:
+        Firstcol = atoi(argv[1]);     /* Get the rectangle to extract */
+        Firstline = atoi(argv[2]);
+        Lastcol = atoi(argv[3]);
+        Lastline = atoi(argv[4]);
+        argv += 4;
+        goto openfile;            /* Yuk, a goto! */
+    case 3:
+        Color= -(atoi(argv[1]));      /* Get the color to extract */
+        argv++;
+    case 2:
+    openfile:
+    spotfile = fopen(argv[1], "rb");  /* Open the input file */
+    if (spotfile == NULL) { perror("fopen"); exit(1); }
+    break;
+    default:
+        usage();
+    }
+
+    while (1)             /* Get a record */
+    {
+        if (pm_readbiglong (spotfile, &arecord.record) == -1)
+            break;
+        arecord.sub1 = fgetc (spotfile);
+        arecord.type = fgetc (spotfile);
+        arecord.sub2 = fgetc (spotfile);
+        arecord.sub3 = fgetc (spotfile);
+        if (pm_readbiglong (spotfile, &arecord.length) == -1)
+            pm_error ("EOF / read error reading a record");
+
+        arecord.length -= 12;   /* Subtract header size as well */
+        if (arecord.type == 0355 && arecord.sub1 == 0355)
+            arecord.length = get_image(arecord.length);
+        else if (arecord.type == 0300 && arecord.sub1 == 077)
+            arecord.length = get_imghdr(arecord.length);
+#ifdef DEBUG
+        else
+            fprintf(stderr, 
+                    "Rcrd %3d, type %03o, stype %03o %03o %03o, length %d\n",
+                    arecord.record, arecord.type, arecord.sub1, arecord.sub2,
+                    (int) arecord.sub3 & 0xff, arecord.length);
+#endif
+        /* Seek to next record */
+        fseek(spotfile, arecord.length, 1);
+    }
+    exit (0);
+}