diff options
author | scuri <scuri> | 2008-10-17 06:10:15 +0000 |
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committer | scuri <scuri> | 2008-10-17 06:10:15 +0000 |
commit | 5a422aba704c375a307a902bafe658342e209906 (patch) | |
tree | 5005011e086bb863d8fb587ad3319bbec59b2447 /src/process/im_statistics.cpp |
First commit - moving from LuaForge to SourceForge
Diffstat (limited to 'src/process/im_statistics.cpp')
-rw-r--r-- | src/process/im_statistics.cpp | 341 |
1 files changed, 341 insertions, 0 deletions
diff --git a/src/process/im_statistics.cpp b/src/process/im_statistics.cpp new file mode 100644 index 0000000..b9f086d --- /dev/null +++ b/src/process/im_statistics.cpp @@ -0,0 +1,341 @@ +/** \file + * \brief Image Statistics Calculations + * + * See Copyright Notice in im_lib.h + * $Id: im_statistics.cpp,v 1.1 2008/10/17 06:16:33 scuri Exp $ + */ + + +#include <im.h> +#include <im_util.h> +#include <im_math_op.h> + +#include "im_process_ana.h" + +#include <stdlib.h> +#include <memory.h> +#include <math.h> + +static unsigned long count_map(const imImage* image) +{ + unsigned long histo[256]; + int size = image->width * image->height; + imCalcHistogram((imbyte*)image->data[0], size, histo, 0); + unsigned long numcolor = 0; + + for (int i = 0; i < 256; i++) + { + if(histo[i] != 0) + numcolor++; + } + + return numcolor; +} + +// will count also all the 3 components color spaces +static unsigned long count_rgb(const imImage* image) +{ + imbyte *count = (imbyte*)calloc(sizeof(imbyte), 1 << 21 ); /* (2^24)/8=2^21 ~ 2Mb */ + if (!count) + return (unsigned long)-1; + + int size = image->width * image->height; + imbyte *red = (imbyte*)image->data[0]; + imbyte *green = (imbyte*)image->data[1]; + imbyte *blue = (imbyte*)image->data[2]; + + int index; + unsigned long numcolor = 0; + + for(int i = 0; i < size; i++) + { + index = red[i] << 16 | green[i] << 8 | blue[i]; + + if(imDataBitGet(count, index) == 0) + numcolor++; + + imDataBitSet(count, index, 1); + } + + free(count); + + return numcolor; +} + +unsigned long imCalcCountColors(const imImage* image) +{ + if (imColorModeDepth(image->color_space) > 1) + return count_rgb(image); + else + return count_map(image); +} + +void imCalcHistogram(const imbyte* map, int size, unsigned long* histo, int cumulative) +{ + int i; + + memset(histo, 0, 256 * sizeof(unsigned long)); + + for (i = 0; i < size; i++) + histo[*map++]++; + + if (cumulative) + { + /* make cumulative histogram */ + for (i = 1; i < 256; i++) + histo[i] += histo[i-1]; + } +} + +void imCalcUShortHistogram(const imushort* map, int size, unsigned long* histo, int cumulative) +{ + int i; + + memset(histo, 0, 65535 * sizeof(unsigned long)); + + for (i = 0; i < size; i++) + histo[*map++]++; + + if (cumulative) + { + /* make cumulative histogram */ + for (i = 1; i < 65535; i++) + histo[i] += histo[i-1]; + } +} + +void imCalcGrayHistogram(const imImage* image, unsigned long* histo, int cumulative) +{ + int i; + + memset(histo, 0, 256 * sizeof(unsigned long)); + + if (image->color_space == IM_GRAY) + { + imbyte* map = (imbyte*)image->data[0]; + for (i = 0; i < image->count; i++) + histo[*map++]++; + } + else if (image->color_space == IM_MAP || image->color_space == IM_BINARY) + { + imbyte* map = (imbyte*)image->data[0]; + imbyte gray_map[256], r, g, b; + + for (i = 0; i < image->palette_count; i++) + { + imColorDecode(&r, &g, &b, image->palette[i]); + gray_map[i] = (imbyte)((299*r + 587*g + 114*b) / 1000); + } + + for (i = 0; i < image->count; i++) + { + int index = *map++; + histo[gray_map[index]]++; + } + } + else + { + imbyte gray; + imbyte* r = (imbyte*)image->data[0]; + imbyte* g = (imbyte*)image->data[1]; + imbyte* b = (imbyte*)image->data[2]; + for (i = 0; i < image->count; i++) + { + gray = (imbyte)((299*(*r++) + 587*(*g++) + 114*(*b++)) / 1000); + histo[gray]++; + } + } + + if (cumulative) + { + /* make cumulative histogram */ + for (i = 1; i < 256; i++) + histo[i] += histo[i-1]; + } +} + +template <class T> +static void DoStats(T* data, int count, imStats* stats) +{ + memset(stats, 0, sizeof(imStats)); + + stats->min = (float)data[0]; + stats->max = (float)data[0]; + + for (int i = 0; i < count; i++) + { + if (data[i] < stats->min) + stats->min = (float)data[i]; + + if (data[i] > stats->max) + stats->max = (float)data[i]; + + if (data[i] > 0) + stats->positive++; + + if (data[i] < 0) + stats->negative++; + + if (data[i] == 0) + stats->zeros++; + + stats->mean += (float)data[i]; + stats->stddev += ((float)data[i])*((float)data[i]); + } + + stats->mean /= float(count); + stats->stddev = (float)sqrt((stats->stddev - count * stats->mean*stats->mean)/(count-1.0)); +} + +void imCalcImageStatistics(const imImage* image, imStats* stats) +{ + int count = image->width * image->height; + + for (int i = 0; i < image->depth; i++) + { + switch(image->data_type) + { + case IM_BYTE: + DoStats((imbyte*)image->data[i], count, &stats[i]); + break; + case IM_USHORT: + DoStats((imushort*)image->data[i], count, &stats[i]); + break; + case IM_INT: + DoStats((int*)image->data[i], count, &stats[i]); + break; + case IM_FLOAT: + DoStats((float*)image->data[i], count, &stats[i]); + break; + } + } +} + +void imCalcHistogramStatistics(const imImage* image, imStats* stats) +{ + int image_size = image->width * image->height; + unsigned long histo[256]; + + for (int d = 0; d < image->depth; d++) + { + imCalcHistogram((imbyte*)image->data[d], image_size, histo, 0); + DoStats((unsigned long*)histo, 256, &stats[d]); + } +} + +void imCalcHistoImageStatistics(const imImage* image, int* median, int* mode) +{ + unsigned long histo[256]; + + for (int d = 0; d < image->depth; d++) + { + int i; + imCalcHistogram((imbyte*)image->data[d], image->count, histo, 0); + + unsigned long half = image->count/2; + unsigned long count = histo[0]; + for (i = 1; i < 256; i++) + { + if (count > half) + { + median[d] = i-1; + break; + } + + count += histo[i]; + } + + unsigned long max = histo[0]; + for (i = 1; i < 256; i++) + { + if (max < histo[i]) + max = histo[i]; + } + + int found_mode = 0; + for (i = 0; i < 256; i++) + { + if (histo[i] == max) + { + if (found_mode) + { + mode[d] = -1; + break; + } + + mode[d] = i; + found_mode = 1; + } + } + } +} + +float imCalcSNR(const imImage* image, const imImage* noise_image) +{ + imStats stats[3]; + imCalcImageStatistics((imImage*)image, stats); + + imStats noise_stats[3]; + imCalcImageStatistics((imImage*)noise_image, noise_stats); + + if (image->color_space == IM_RGB) + { + noise_stats[0].stddev += noise_stats[1].stddev; + noise_stats[0].stddev += noise_stats[2].stddev; + noise_stats[0].stddev /= 3; + stats[0].stddev += stats[1].stddev; + stats[0].stddev += stats[2].stddev; + stats[0].stddev /= 3; + } + + if (noise_stats[0].stddev == 0) + return 0; + + return float(20.*log10(stats[0].stddev / noise_stats[0].stddev)); +} + +template <class T> +static float DoRMSOp(T *map1, T *map2, int count) +{ + float rmserror = 0.0f; + float diff; + + for (int i = 0; i < count; i++) + { + diff = float(map1[i] - map2[i]); + rmserror += diff * diff; + } + + return rmserror; +} + +float imCalcRMSError(const imImage* image1, const imImage* image2) +{ + float rmserror = 0.0f; + + int count = image1->count*image1->depth; + + switch(image1->data_type) + { + case IM_BYTE: + rmserror = DoRMSOp((imbyte*)image1->data[0], (imbyte*)image2->data[0], count); + break; + case IM_USHORT: + rmserror = DoRMSOp((imushort*)image1->data[0], (imushort*)image2->data[0], count); + break; + case IM_INT: + rmserror = DoRMSOp((int*)image1->data[0], (int*)image2->data[0], count); + break; + case IM_FLOAT: + rmserror = DoRMSOp((float*)image1->data[0], (float*)image2->data[0], count); + break; + case IM_CFLOAT: + rmserror = DoRMSOp((float*)image1->data[0], (float*)image2->data[0], 2*count); + break; + } + + rmserror = float(sqrt(rmserror / float((count * image1->depth)))); + + return rmserror; +} + |