w2img::ImageComparator Class Reference

Inheritance diagram for w2img::ImageComparator:

List of all members.

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Detailed Description

Compares two images and gives estimates of how much image b resembles image a (the first input to all the score methods is assumed to be the real thing and the second an estimate).

Images that are invalid in both images do not contribute to the denominator of the mean square error etc. For further information on the algorithm used, see the documentation of Score::updateScore

Author:

Lakshman

Version:

Id

w2img_ImageComparator.h,v 1.13 2009/06/02 20:17:57 lakshman Exp

Public Member Functions
	ImageComparator (double minValue, double maxValue, bool maxIsBetter, const std::vector< code::Image< float > > &kernels, size_t searchDistance=0, bool includeNulls=false)
	Compare two images.
virtual	~ImageComparator ()
std::vector< Score >	score (const code::CartesianGrid2D &orig, const code::CartesianGrid2D &fil) const
	the two images should be of identical sizes.
std::vector< Score >	score (const code::LatLonGrid &orig, const code::LatLonGrid &fil) const
	the two images should be of identical sizes.
std::vector< Score >	score (const code::PolarGrid &orig, const code::PolarGrid &fil) const
	the two images should be of identical sizes.
std::vector< Score >	score (const code::Image< float > &orig, const code::Image< float > &fil) const
virtual Score	scoreFiltered (const code::Image< float > &orig, const code::Image< float > &fil) const
	returns the score for pre-filtered images.
void	updateScore (double orig, double filtered, ImageComparator::Score *score) const
	Updates this score based on the orig and filtered values if findError returns true.
bool	findError (double orig, double filtered, double &error, bool &origValid, bool &estValid) const
	Find the error.
Protected Attributes
std::vector< code::SmartPtr< KernelFilter > >	filters
double	minValue
double	maxValue
bool	maxIsBetter
int	searchRadius
bool	includeNulls
Classes
class	Score

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Constructor & Destructor Documentation

w2img::ImageComparator::ImageComparator	(	double	minValue,
		double	maxValue,
		bool	maxIsBetter,
		const std::vector< code::Image< float > > &	kernels,
		size_t	searchDistance = 0,
		bool	includeNulls = false
	)

Compare two images.

Values in the range minValue-maxValue are considered.

The kernel is used to smooth the filtered image before searching. A box within the search-radius is searched for the best match (lowest error) -- pass in a radius of 0 to just use the pixel value.

virtual w2img::ImageComparator::~ImageComparator

(

)

[inline, virtual]

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Member Function Documentation

bool w2img::ImageComparator::findError	(	double	orig,
		double	filtered,
		double &	error,
		bool &	origValid,
		bool &	estValid
	)			const

Find the error.

The error is (filtered - orig) if both numbers are valid.

Returns:

true if the error returned is a usable number The error will be flagged as Constants::MissingData if both orig and filtered are invalid unless includeNulls was set in the constructor. Definition: An invalid value is a value equal to Constants::MISSING_DATA or less than minValue (if maxIsBetter).

std::vector<Score> w2img::ImageComparator::score	(	const code::Image< float > &	orig,
		const code::Image< float > &	fil
	)			const

std::vector<Score> w2img::ImageComparator::score	(	const code::PolarGrid &	orig,
		const code::PolarGrid &	fil
	)			const

the two images should be of identical sizes.

std::vector<Score> w2img::ImageComparator::score	(	const code::LatLonGrid &	orig,
		const code::LatLonGrid &	fil
	)			const

the two images should be of identical sizes.

std::vector<Score> w2img::ImageComparator::score	(	const code::CartesianGrid2D &	orig,
		const code::CartesianGrid2D &	fil
	)			const

the two images should be of identical sizes.

the return is the Score for each of the given kernels.

virtual Score w2img::ImageComparator::scoreFiltered	(	const code::Image< float > &	orig,
		const code::Image< float > &	fil
	)			const [virtual]

returns the score for pre-filtered images.

Reimplemented in w2img::ProbabilisticImageComparator, and w2kmeans::ObjectImageComparator.

void w2img::ImageComparator::updateScore	(	double	orig,
		double	filtered,
		ImageComparator::Score *	score
	)			const

Updates this score based on the orig and filtered values if findError returns true.

See also:

findError

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Member Data Documentation

std::vector< code::SmartPtr<KernelFilter> > w2img::ImageComparator::filters [protected]

bool w2img::ImageComparator::includeNulls [protected]

bool w2img::ImageComparator::maxIsBetter [protected]

double w2img::ImageComparator::maxValue [protected]

double w2img::ImageComparator::minValue [protected]

int w2img::ImageComparator::searchRadius [protected]

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