ImageMagick: MagickCore, C API for ImageMagick: Image Statistics

EvaluateImage • FunctionImage • GetImageEntropy • GetImageExtrema • GetImageKurtosis • GetImageMean • GetImageMoments • GetImagePerceptualHash • GetImageRange • GetImageStatistics • PolynomialImage • StatisticImage

EvaluateImage

EvaluateImage() applies a value to the image with an arithmetic, relational, or logical operator to an image. Use these operations to lighten or darken an image, to increase or decrease contrast in an image, or to produce the "negative" of an image.

The format of the EvaluateImage method is:

MagickBooleanType EvaluateImage(Image *image,
  const MagickEvaluateOperator op,const double value,
  ExceptionInfo *exception)
MagickBooleanType EvaluateImages(Image *images,
  const MagickEvaluateOperator op,const double value,
  ExceptionInfo *exception)

A description of each parameter follows:

image: the image.
op: A channel op.
value: A value value.
exception: return any errors or warnings in this structure.

FunctionImage

FunctionImage() applies a value to the image with an arithmetic, relational, or logical operator to an image. Use these operations to lighten or darken an image, to increase or decrease contrast in an image, or to produce the "negative" of an image.

The format of the FunctionImage method is:

MagickBooleanType FunctionImage(Image *image,
  const MagickFunction function,const ssize_t number_parameters,
  const double *parameters,ExceptionInfo *exception)

A description of each parameter follows:

image: the image.
function: A channel function.
parameters: one or more parameters.
exception: return any errors or warnings in this structure.

GetImageEntropy

GetImageEntropy() returns the entropy of one or more image channels.

The format of the GetImageEntropy method is:

MagickBooleanType GetImageEntropy(const Image *image,double *entropy,
  ExceptionInfo *exception)

A description of each parameter follows:

image: the image.
entropy: the average entropy of the selected channels.
exception: return any errors or warnings in this structure.

GetImageExtrema

GetImageExtrema() returns the extrema of one or more image channels.

The format of the GetImageExtrema method is:

MagickBooleanType GetImageExtrema(const Image *image,size_t *minima,
  size_t *maxima,ExceptionInfo *exception)

A description of each parameter follows:

image: the image.
minima: the minimum value in the channel.
maxima: the maximum value in the channel.
exception: return any errors or warnings in this structure.

GetImageKurtosis

GetImageKurtosis() returns the kurtosis and skewness of one or more image channels.

The format of the GetImageKurtosis method is:

MagickBooleanType GetImageKurtosis(const Image *image,double *kurtosis,
  double *skewness,ExceptionInfo *exception)

A description of each parameter follows:

image: the image.
kurtosis: the kurtosis of the channel.
skewness: the skewness of the channel.
exception: return any errors or warnings in this structure.

GetImageMean

GetImageMean() returns the mean and standard deviation of one or more image channels.

The format of the GetImageMean method is:

MagickBooleanType GetImageMean(const Image *image,double *mean,
  double *standard_deviation,ExceptionInfo *exception)

A description of each parameter follows:

image: the image.
mean: the average value in the channel.
standard_deviation: the standard deviation of the channel.
exception: return any errors or warnings in this structure.

GetImageMoments

GetImageMoments() returns the normalized moments of one or more image channels.

The format of the GetImageMoments method is:

ChannelMoments *GetImageMoments(const Image *image,
  ExceptionInfo *exception)

A description of each parameter follows:

image: the image.
exception: return any errors or warnings in this structure.

GetImagePerceptualHash

GetImagePerceptualHash() returns the perceptual hash of one or more image channels.

The format of the GetImagePerceptualHash method is:

ChannelPerceptualHash *GetImagePerceptualHash(const Image *image,
  ExceptionInfo *exception)

A description of each parameter follows:

image: the image.
exception: return any errors or warnings in this structure.

GetImageRange

GetImageRange() returns the range of one or more image channels.

The format of the GetImageRange method is:

MagickBooleanType GetImageRange(const Image *image,double *minima,
  double *maxima,ExceptionInfo *exception)

A description of each parameter follows:

image: the image.
minima: the minimum value in the channel.
maxima: the maximum value in the channel.
exception: return any errors or warnings in this structure.

GetImageStatistics

GetImageStatistics() returns statistics for each channel in the image. The statistics include the channel depth, its minima, maxima, mean, standard deviation, kurtosis and skewness. You can access the red channel mean, for example, like this:

channel_statistics=GetImageStatistics(image,exception);
red_mean=channel_statistics[RedPixelChannel].mean;

Use MagickRelinquishMemory() to free the statistics buffer.

The format of the GetImageStatistics method is:

ChannelStatistics *GetImageStatistics(const Image *image,
  ExceptionInfo *exception)

A description of each parameter follows:

image: the image.
exception: return any errors or warnings in this structure.

PolynomialImage

PolynomialImage() returns a new image where each pixel is the sum of the pixels in the image sequence after applying its corresponding terms (coefficient and degree pairs).

The format of the PolynomialImage method is:

Image *PolynomialImage(const Image *images,const size_t number_terms,
  const double *terms,ExceptionInfo *exception)

A description of each parameter follows:

images: the image sequence.
number_terms: the number of terms in the list. The actual list length is 2 x number_terms + 1 (the constant).
terms: the list of polynomial coefficients and degree pairs and a constant.
exception: return any errors or warnings in this structure.

StatisticImage

StatisticImage() makes each pixel the min / max / median / mode / etc. of the neighborhood of the specified width and height.

The format of the StatisticImage method is:

Image *StatisticImage(const Image *image,const StatisticType type,
  const size_t width,const size_t height,ExceptionInfo *exception)

A description of each parameter follows:

image: the image.
type: the statistic type (median, mode, etc.).
width: the width of the pixel neighborhood.
height: the height of the pixel neighborhood.
exception: return any errors or warnings in this structure.