IM: Image Statistics Calculations

IM - An Imaging Tool

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Image Statistics Calculations
[Image Processing]

Detailed Description

Operations to calculate some statistics over images.
See im_process_ana.h


Data Structures

struct  _imStats

Typedefs

typedef _imStats imStats

Functions

float imCalcRMSError (const imImage *image1, const imImage *image2)
float imCalcSNR (const imImage *src_image, const imImage *noise_image)
unsigned long imCalcCountColors (const imImage *image)
void imCalcHistogram (const unsigned char *data, int count, unsigned long *histo, int cumulative)
void imCalcUShortHistogram (const unsigned short *data, int count, unsigned long *histo, int cumulative)
void imCalcGrayHistogram (const imImage *image, unsigned long *histo, int cumulative)
void imCalcImageStatistics (const imImage *image, imStats *stats)
void imCalcHistogramStatistics (const imImage *image, imStats *stats)
void imCalcHistoImageStatistics (const imImage *image, int *median, int *mode)

Typedef Documentation

typedef struct _imStats imStats
 

Numerical Statistics Structure

Function Documentation

float imCalcRMSError (  const imImage *  image1,
const imImage *  image2
) 
 

Calculates the RMS error between two images (Root Mean Square Error).

im.CalcRMSError(image1: imImage, image2: imImage) -> rms: number [in Lua 5]

float imCalcSNR (  const imImage *  src_image,
const imImage *  noise_image
) 
 

Calculates the SNR of an image and its noise (Signal Noise Ratio).

im.CalcSNR(src_image: imImage, noise_image: imImage) -> snr: number [in Lua 5]

unsigned long imCalcCountColors (  const imImage *  image  ) 
 

Count the number of different colors in an image.
Image must be IM_BYTE, but all color spaces except IM_CMYK.

im.CalcCountColors(image: imImage) -> count: number [in Lua 5]

void imCalcHistogram (  const unsigned char *  data,
int  count,
unsigned long *  histo,
int  cumulative
) 
 

Calculates the histogram of a IM_BYTE data.
Histogram is always 256 positions long.
When cumulative is different from zero it calculates the cumulative histogram.

im.CalcHistogram(image: imImage, plane: number, cumulative: number) -> histo: table of numbers [in Lua 5]
Where plane is the depth plane to calculate the histogram.
The returned table is zero indexed. image can be IM_USHORT or IM_BYTE.

void imCalcUShortHistogram (  const unsigned short *  data,
int  count,
unsigned long *  histo,
int  cumulative
) 
 

Calculates the histogram of a IM_USHORT data.
Histogram is always 65535 positions long.
When cumulative is different from zero it calculates the cumulative histogram.
Use imCalcHistogram in Lua.

void imCalcGrayHistogram (  const imImage *  image,
unsigned long *  histo,
int  cumulative
) 
 

Calculates the gray histogram of an image.
Image must be IM_BYTE/(IM_RGB, IM_GRAY, IM_BINARY or IM_MAP).
If the image is IM_RGB then the histogram of the luma component is calculated.
Histogram is always 256 positions long.
When cumulative is different from zero it calculates the cumulative histogram.

im.CalcGrayHistogram(image: imImage, cumulative: number) -> histo: table of numbers [in Lua 5]

void imCalcImageStatistics (  const imImage *  image,
imStats *  stats
) 
 

Calculates the statistics about the image data.
There is one stats for each depth plane. For ex: stats[0]=red stats, stats[0]=green stats, ...
Supports all data types except IM_CFLOAT. 

im.CalcImageStatistics(image: imImage) -> stats: table [in Lua 5]
Table contains the following fields: max, min, positive, negative, zeros, mean, stddev. The same as the imStats structure.

void imCalcHistogramStatistics (  const imImage *  image,
imStats *  stats
) 
 

Calculates the statistics about the image histogram data.
There is one stats for each depth plane. For ex: stats[0]=red stats, stats[0]=green stats, ...
Only IM_BYTE images are supported.

im.CalcHistogramStatistics(image: imImage) -> stats: table [in Lua 5]

void imCalcHistoImageStatistics (  const imImage *  image,
int *  median,
int *  mode
) 
 

Calculates some extra statistics about the image histogram data.
There is one stats for each depth plane.
Only IM_BYTE images are supported.
mode will be -1 if more than one max is found.

im.CalcHistoImageStatistics(image: imImage) -> median: number, mode: number [in Lua 5]


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