diff options
Diffstat (limited to 'editor/pnmnorm.c')
| -rw-r--r-- | editor/pnmnorm.c | 158 |
1 files changed, 115 insertions, 43 deletions
diff --git a/editor/pnmnorm.c b/editor/pnmnorm.c index 3a181bf3..8c25df80 100644 --- a/editor/pnmnorm.c +++ b/editor/pnmnorm.c @@ -38,7 +38,7 @@ enum brightMethod {BRIGHT_LUMINOSITY, BRIGHT_COLORVALUE, BRIGHT_SATURATION}; -struct cmdlineInfo { +struct CmdlineInfo { /* All the information the user supplied in the command line, in a form easy for the program to use. */ @@ -70,7 +70,7 @@ struct cmdlineInfo { static void parseCommandLine(int argc, const char ** argv, - struct cmdlineInfo * const cmdlineP) { + struct CmdlineInfo * const cmdlineP) { /*---------------------------------------------------------------------------- parse program command line described in Unix standard form by argc and argv. Return the information in the options as *cmdlineP. @@ -265,7 +265,12 @@ buildHistogram(FILE * const ifp, static xelval minimumValue(const unsigned int * const hist, unsigned int const highest) { +/*---------------------------------------------------------------------------- + The minimum brightness in the image, according to histogram 'hist', + which goes up to 'highest'. + Abort the program if there are no pixels of any brightness. +-----------------------------------------------------------------------------*/ xelval i; bool foundOne; @@ -274,7 +279,8 @@ minimumValue(const unsigned int * const hist, foundOne = true; else { if (i == highest) - pm_error("INTERNAL ERROR in '%s'. No pixels", __FUNCTION__); + pm_error("INTERNAL ERROR in function 'minimumValue'. " + "No pixels"); else ++i; } @@ -287,7 +293,12 @@ minimumValue(const unsigned int * const hist, static xelval maximumValue(const unsigned int * const hist, unsigned int const highest) { +/*---------------------------------------------------------------------------- + The maximum brightness in the image, according to histogram 'hist', + which goes up to 'highest'. + Abort the program if there are no pixels of any brightness. +-----------------------------------------------------------------------------*/ xelval i; bool foundOne; @@ -296,7 +307,8 @@ maximumValue(const unsigned int * const hist, foundOne = true; else { if (i == 0) - pm_error("INTERNAL ERROR in '%s'. No pixels", __FUNCTION__); + pm_error("INTERNAL ERROR in function 'maximumValue'. " + "No pixels"); else --i; } @@ -306,12 +318,32 @@ maximumValue(const unsigned int * const hist, +static unsigned int +brightnessCount(const unsigned int * const hist, + unsigned int const highest) { +/*---------------------------------------------------------------------------- + The number of distinct brightnesses in the image according to + histogram 'hist', which goes up to brightness 'highest'. +-----------------------------------------------------------------------------*/ + xelval i; + unsigned int nonzeroCount; + + for (i = 0, nonzeroCount = 0; i <= highest; ++i) { + if (hist[i] > 0) + ++nonzeroCount; + } + + return nonzeroCount; +} + + + static void -computeBottomPercentile(unsigned int hist[], - unsigned int const highest, - unsigned int const total, - float const percent, - unsigned int * const percentileP) { +computeBottomPercentile(const unsigned int * const hist, + unsigned int const highest, + unsigned int const total, + float const percent, + unsigned int * const percentileP) { /*---------------------------------------------------------------------------- Compute the lowest index of hist[] such that the sum of the hist[] values with that index and lower represent at least 'percent' per cent of @@ -339,11 +371,11 @@ computeBottomPercentile(unsigned int hist[], static void -computeTopPercentile(unsigned int hist[], - unsigned int const highest, - unsigned int const total, - float const percent, - unsigned int * const percentileP) { +computeTopPercentile(const unsigned int * const hist, + unsigned int const highest, + unsigned int const total, + float const percent, + unsigned int * const percentileP) { /*---------------------------------------------------------------------------- Compute the highest index of hist[] such that the sum of the hist[] values with that index and higher represent 'percent' per cent of @@ -494,13 +526,68 @@ disOverlap(xelval const reqBvalue, +static xelval +resolvedPctBvalue(const unsigned int * const hist, + unsigned int const totalPixelCt, + xelval const maxval, + struct CmdlineInfo const cmdline) { + + xelval retval; + + if (cmdline.bsingle) + retval = minimumValue(hist, maxval); + else if (cmdline.bvalueSpec && !cmdline.bpercentSpec) { + retval = cmdline.bvalue; + } else { + xelval percentBvalue; + + computeBottomPercentile(hist, maxval, totalPixelCt, cmdline.bpercent, + &percentBvalue); + if (cmdline.bvalueSpec) + retval = MIN(percentBvalue, cmdline.bvalue); + else + retval = percentBvalue; + } + return retval; +} + + + +static xelval +resolvedPctWvalue(const unsigned int * const hist, + unsigned int const totalPixelCt, + xelval const maxval, + struct CmdlineInfo const cmdline) { + + xelval retval; + + if (cmdline.wsingle) + retval = maximumValue(hist, maxval); + else if (cmdline.wvalueSpec && !cmdline.wpercentSpec) { + retval = cmdline.wvalue; + } else { + xelval percentWvalue; + + computeTopPercentile(hist, maxval, totalPixelCt, cmdline.wpercent, + &percentWvalue); + if (cmdline.wvalueSpec) + retval = MAX(percentWvalue, cmdline.wvalue); + else + retval = percentWvalue; + } + + return retval; +} + + + static void resolvePercentParams(FILE * const ifP, unsigned int const cols, unsigned int const rows, xelval const maxval, int const format, - struct cmdlineInfo const cmdline, + struct CmdlineInfo const cmdline, xelval * const bvalueP, xelval * const wvalueP) { /*---------------------------------------------------------------------------- @@ -521,32 +608,17 @@ resolvePercentParams(FILE * const ifP, buildHistogram(ifP, cols, rows, maxval, format, hist, cmdline.brightMethod); - if (cmdline.bsingle) - *bvalueP = minimumValue(hist, maxval); - else if (cmdline.bvalueSpec && !cmdline.bpercentSpec) { - *bvalueP = cmdline.bvalue; + if (!cmdline.bvalueSpec && !cmdline.wvalueSpec && + brightnessCount(hist, maxval) < 2) { + /* Special case - you can't stretch a single brightness to both + ends. So just don't stretch at all. + */ + *bvalueP = 0; + *wvalueP = maxval; } else { - xelval percentBvalue; - computeBottomPercentile(hist, maxval, cols*rows, cmdline.bpercent, - &percentBvalue); - if (cmdline.bvalueSpec) - *bvalueP = MIN(percentBvalue, cmdline.bvalue); - else - *bvalueP = percentBvalue; - } + *bvalueP = resolvedPctBvalue(hist, cols * rows, maxval, cmdline); - if (cmdline.wsingle) - *wvalueP = maximumValue(hist, maxval); - else if (cmdline.wvalueSpec && !cmdline.wpercentSpec) { - *wvalueP = cmdline.wvalue; - } else { - xelval percentWvalue; - computeTopPercentile(hist, maxval, cols*rows, cmdline.wpercent, - &percentWvalue); - if (cmdline.wvalueSpec) - *wvalueP = MAX(percentWvalue, cmdline.wvalue); - else - *wvalueP = percentWvalue; + *wvalueP = resolvedPctWvalue(hist, cols * rows, maxval, cmdline); } free(hist); } @@ -560,7 +632,7 @@ computeEndValues(FILE * const ifP, int const rows, xelval const maxval, int const format, - struct cmdlineInfo const cmdline, + struct CmdlineInfo const cmdline, xelval * const bvalueP, xelval * const wvalueP, bool * const quadraticP, @@ -627,7 +699,7 @@ computeLinearTransfer(xelval const bvalue, unsigned int val; /* The following for structure is a hand optimization of this one: for (i = bvalue; i <= wvalue; ++i) - newBrightness[i] = (i-bvalue)*maxval/range); + newBrightness[i] = (i-bvalue)*maxval/range); (with proper rounding) */ for (i = bvalue, val = range/2; @@ -935,8 +1007,8 @@ reportTransferParm(bool const quadratic, int main(int argc, const char *argv[]) { - struct cmdlineInfo cmdline; - FILE *ifP; + struct CmdlineInfo cmdline; + FILE * ifP; pm_filepos imagePos; xelval maxval; int rows, cols, format; |