1 files changed, 291 insertions, 0 deletions
diff --git a/other/pamfix.c b/other/pamfix.c
new file mode 100644
index 00000000..8db67e08
--- /dev/null
+++ b/other/pamfix.c
@@ -0,0 +1,291 @@
+/*============================================================================
+                                 pamfix
+==============================================================================
+  Salvage a Netpbm image that is corrupted in certain ways.
+
+  By Bryan Henderson, January 2007.
+
+  Contributed to the public domain by its author.
+============================================================================*/
+
+#include <setjmp.h>
+
+#include "pm_c_util.h"
+#include "pam.h"
+#include "shhopt.h"
+#include "mallocvar.h"
+
+struct cmdlineInfo {
+    /* All the information the user supplied in the command line,
+       in a form easy for the program to use.
+    */
+    const char * inputFileName;   /* File name of input file */
+    unsigned int verbose;
+    unsigned int truncate;
+    unsigned int changemaxval;
+    unsigned int clip;
+};
+
+
+
+static void
+parseCommandLine(int argc, char ** const argv,
+                 struct cmdlineInfo * const cmdlineP) {
+/*----------------------------------------------------------------------------
+   Note that the file spec array we return is stored in the storage that
+   was passed to us as the argv array.
+-----------------------------------------------------------------------------*/
+    optEntry * option_def;
+
+    optStruct3 opt;
+
+    unsigned int option_def_index;
+
+    MALLOCARRAY(option_def, 100);
+
+    option_def_index = 0;   /* incremented by OPTENTRY */
+
+    OPTENT3(0, "verbose",      OPT_FLAG, NULL, &cmdlineP->verbose,      0);
+    OPTENT3(0, "truncate",     OPT_FLAG, NULL, &cmdlineP->truncate,     0);
+    OPTENT3(0, "changemaxval", OPT_FLAG, NULL, &cmdlineP->changemaxval, 0);
+    OPTENT3(0, "clip",         OPT_FLAG, NULL, &cmdlineP->clip,         0);
+
+    opt.opt_table = option_def;
+    opt.short_allowed = FALSE;  /* We have no short (old-fashioned) options */
+    opt.allowNegNum = FALSE;  /* We don't parms that are negative numbers */
+
+    pm_optParseOptions3(&argc, argv, opt, sizeof(opt), 0);
+        /* Uses and sets argc, argv, and some of *cmdlineP and others. */
+    free(option_def);
+
+    if (argc-1 == 0) 
+        cmdlineP->inputFileName = "-";
+    else if (argc-1 != 1)
+        pm_error("Program takes zero or one argument (filename).  You "
+                 "specified %d", argc-1);
+    else
+        cmdlineP->inputFileName = argv[1];
+
+    if (cmdlineP->changemaxval && cmdlineP->clip)
+        pm_error("You cannot specify both -changemaxval and -clip");
+}
+
+
+
+static unsigned int readErrRow;
+static bool readErrVerbose;
+
+static pm_usererrormsgfn handleRowErrMsg;
+
+static void
+handleRowErrMsg(const char * const msg) {
+    if (readErrVerbose)
+        pm_message("Error reading row %u: %s", readErrRow, msg);
+}
+
+
+static sample
+highestSampleInRow(const struct pam * const pamP,
+                   tuple *            const tuplerow) {
+
+    unsigned int col;
+    sample highestSoFar;
+
+    for (col = 0, highestSoFar = 0; col < pamP->width; ++col) {
+        unsigned int plane;
+        for (plane = 0; plane < pamP->depth; ++plane)
+            highestSoFar = MAX(highestSoFar, tuplerow[col][plane]);
+    }
+    return highestSoFar;
+}
+
+
+
+static void
+analyzeRaster(const struct pam * const pamP,
+              unsigned int *     const goodRowCountP,
+              sample *           const highestSampleP,
+              bool               const mustAbortOnReadError,
+              bool               const verbose) {
+/*----------------------------------------------------------------------------
+   Go through the raster at which the stream described by *tweakedPamP is
+   presently positioned and count how many rows can be successfully read
+   (including validating the samples against pamP->maxval) and determine the
+   highest sample value in those rows.
+
+   Leave the stream positioned arbitrarily.
+-----------------------------------------------------------------------------*/
+    tuple * tuplerow;
+    unsigned int row;
+    jmp_buf jmpbuf;
+    int rc;
+    
+    tuplerow = pnm_allocpamrow(pamP);
+
+    pm_setusererrormsgfn(handleRowErrMsg);
+
+    rc = setjmp(jmpbuf);
+    if (rc == 0) {
+        pm_setjmpbuf(&jmpbuf);
+
+        readErrVerbose  = mustAbortOnReadError || verbose;
+        *goodRowCountP  = 0;  /* initial value */
+        *highestSampleP = 0;  /* initial value */
+
+        for (row = 0; row < pamP->height; ++row) {
+            readErrRow = row;
+            pnm_readpamrow(pamP, tuplerow);
+            /* The above does not return if it can't read the next row from
+               the file.  Instead, it longjmps out of this loop.
+
+               Update return stats now in case the next iteration longjmps out.
+            */
+            *highestSampleP =
+                MAX(*highestSampleP,
+                    highestSampleInRow(pamP, tuplerow));
+            ++*goodRowCountP;
+        }
+    } else {
+        /* pnm_readpamrow() encountered an error and longjmped */
+        if (mustAbortOnReadError) {
+            /* handleRowErrMsg() has issued the error message */
+            exit(1);
+        }
+    }
+    pm_setjmpbuf(NULL);
+
+    pm_setusererrormsgfn(NULL);
+
+    pnm_freepamrow(tuplerow);
+}
+
+
+
+static void
+clipPamRow(const struct pam * const pamP,
+           tuple *            const tuplerow,
+           unsigned int       const row,
+           bool               const verbose) {
+/*----------------------------------------------------------------------------
+   Clip every sample value in tuplerow[] to the maxval.
+
+   If 'verbose' is true, issue messages about every clipping, indicating it
+   is in row 'row'.
+-----------------------------------------------------------------------------*/
+    unsigned int col;
+
+    for (col = 0; col < pamP->width; ++col) {
+        unsigned int plane;
+        for (plane = 0; plane < pamP->depth; ++plane) {
+            if (tuplerow[col][plane] > pamP->maxval) {
+                if (verbose) 
+                    pm_message("Clipping: Row %u Col %u Plane %u.  "
+                               "Sample value %lu exceeds the "
+                               "image maxval of %lu",
+                               row, col, plane, tuplerow[col][plane],
+                               pamP->maxval);
+	            tuplerow[col][plane] = pamP->maxval;
+            }
+        }
+    }
+}
+
+
+
+static void
+copyGoodRows(const struct pam * const inpamP,
+             const struct pam * const outpamP,
+             bool               const verbose) {
+/*----------------------------------------------------------------------------
+  Copy the raster of the input stream described by *inpamP to the output
+  stream described by *outpamP.  Copy only as many rows as *outpamP allows;
+  assume *outpamP specifies at most the number of rows of input.
+-----------------------------------------------------------------------------*/
+    tuple * tuplerow;
+    unsigned int row;
+
+    tuplerow = pnm_allocpamrow(inpamP);
+
+    for (row = 0; row < outpamP->height; ++row) {
+        pnm_readpamrow(inpamP, tuplerow);
+        clipPamRow(outpamP, tuplerow, row, verbose);
+        pnm_writepamrow(outpamP, tuplerow);
+    }
+    
+    pnm_freepamrow(tuplerow);
+}
+
+
+
+int
+main(int argc, char * argv[]) {
+    struct cmdlineInfo cmdline;
+    struct pam inpam;
+    struct pam outpam;
+    struct pam tweakedPam;
+    FILE * ifP;
+    pm_filepos rasterPos;
+    unsigned int goodRowCount;
+    sample highestSample;
+
+    pnm_init(&argc, argv);
+
+    parseCommandLine(argc, argv, &cmdline);
+
+    ifP = pm_openr_seekable(cmdline.inputFileName);
+
+    pnm_readpaminit(ifP, &inpam, PAM_STRUCT_SIZE(tuple_type));
+
+    pm_tell2(ifP, &rasterPos, sizeof(rasterPos));
+
+    /* Tweak maxval to circumvent out-of-bounds sample value check
+       in libpam.  See function validatePamRow() in libpamread.c .
+
+       Ideally we would like to set tweaked-maxval higher for the
+       plain (text) formats.  We make a compromise to keep things
+       simple.
+    */
+
+    tweakedPam = inpam;  /* initial value */
+
+    if ((cmdline.clip || cmdline.changemaxval)
+        && PNM_FORMAT_TYPE(inpam.format) != PBM_TYPE)
+        tweakedPam.maxval =
+            (((sample) 1) << tweakedPam.bytes_per_sample * 8) - 1;
+
+    analyzeRaster(&tweakedPam, &goodRowCount, &highestSample,
+                  !cmdline.truncate, cmdline.verbose);
+
+    if (goodRowCount == 0)
+        pm_error("Cannot read a single row from the image%s",
+                 cmdline.verbose ? "" : ".  Use -verbose to find out why");
+
+    if (goodRowCount < inpam.height)
+        pm_message("Copying %u good rows; %u bottom rows missing%s",
+                   goodRowCount, inpam.height - goodRowCount,
+                   cmdline.verbose ? "" : ".  Use -verbose to find out why");
+
+    pm_seek2(ifP, &rasterPos, sizeof(rasterPos));
+
+    outpam = inpam;  /* initial value */
+
+    outpam.file = stdout;
+    outpam.height = goodRowCount;
+    if (cmdline.changemaxval && highestSample > outpam.maxval) {
+        pm_message("Raising maxval from %lu to %lu to legitimize "
+                   "all sample values",
+                    outpam.maxval, highestSample);
+        outpam.maxval = highestSample;
+    }
+
+    pnm_writepaminit(&outpam);
+
+    copyGoodRows(&tweakedPam, &outpam, cmdline.verbose);
+
+    pm_close(inpam.file);
+    
+    return 0;
+}
+
+
+