#include <vpImage.h>

Public Member Functions
	vpImage ()

	vpImage (const vpImage< Type > &)

	vpImage (unsigned int height, unsigned int width)

	vpImage (unsigned int height, unsigned int width, Type value)

virtual	~vpImage ()

void	init (unsigned int height, unsigned int width)

void	init (unsigned int height, unsigned int width, Type value)

void	resize (const unsigned int h, const unsigned int w)

void	resize (const unsigned int h, const unsigned int w, const Type val)

void	destroy ()

unsigned int	getHeight () const

unsigned int	getWidth () const

unsigned int	getRows () const

unsigned int	getCols () const

unsigned int	getSize () const

Type	getMaxValue () const

Type	getMinValue () const

void	getMinMaxValue (Type &min, Type &max) const

Type	getValue (double i, double j) const

Type	getValue (vpImagePoint &ip) const

unsigned int	getNumberOfPixel () const

Type *	operator[] (const unsigned int i)

Type *	operator[] (const int i)

const Type *	operator[] (unsigned int i) const

const Type *	operator[] (int i) const

Type	operator() (const unsigned int i, const unsigned int j) const

void	operator() (const unsigned int i, const unsigned int j, const Type &v)

Type	operator() (const vpImagePoint &ip) const

void	operator() (const vpImagePoint &ip, const Type &v)

vpImage< Type >	operator- (const vpImage< Type > &B)

vpImage< Type > &	operator= (const vpImage< Type > &I)

vpImage< Type > &	operator= (const Type &v)

bool	operator== (const vpImage< Type > &I)

bool	operator!= (const vpImage< Type > &I)

void	insert (const vpImage< Type > &src, const vpImagePoint topLeft)

void	halfSizeImage (vpImage< Type > &res)

void	quarterSizeImage (vpImage< Type > &res)

void	doubleSizeImage (vpImage< Type > &res)

void	sub (const vpImage< Type > &B, vpImage< Type > &C)

void	sub (const vpImage< Type > &A, const vpImage< Type > &B, vpImage< Type > &C)

Public Attributes
Type *	bitmap

vpDisplay *	display

Friends
class	vpImageConvert

Deprecated functions
vp_deprecated void	sub (vpImage< Type > im2, vpImage< Type > dst)

vp_deprecated void	halfSizeImage (vpImage< Type > *res)

vp_deprecated void	quarterSizeImage (vpImage< Type > *res)

vp_deprecated void	doubleSizeImage (vpImage< Type > *res)

Detailed Description

template<class Type>
class vpImage< Type >

Definition of the vpImage class member functions.

This is a template class, therefore the type of each element of the array is not a priori defined.

Data structure

Each image is build using two structure (an array bitmap which size is [width*height]) and an array of pointer row (which size is [nrow]) the ith element in the row array row[i] is pointer toward the ith "line" of the image (ie, bitmap +i*width )

Such a structure allows a fast acces to each element of the image. if i is the ith rows and j the jth columns the value of this pixel is given by I[i][j] (that is equivalent to row[i][j]).

Example

The following example available in tutorial-image-manipulation.cpp shows how to create gray level and color images and how to access to the pixels.

#include <visp/vpImage.h>
int main()
{
  try {
    vpImage<unsigned char> gray_image(240, 320);
    vpImage<vpRGBa> color_image(240, 320);
    gray_image = 128;
    vpRGBa color(255, 0, 0);
    color_image = color;
    unsigned int igray_max = gray_image.getHeight() - 1;
    unsigned int jgray_max = gray_image.getWidth() - 1;
    std::cout << "Gray  image, last pixel intensity: "
              <<  (int)gray_image[igray_max][jgray_max] << std::endl;
    unsigned int icolor_max = color_image.getHeight() - 1;
    unsigned int jcolor_max = color_image.getWidth() - 1;
    std::cout << "Color image, last pixel RGB components: "
              << (int)color_image[icolor_max][jcolor_max].R << " "
              << (int)color_image[icolor_max][jcolor_max].G << " "
              << (int)color_image[icolor_max][jcolor_max].B
              << std::endl;
  }
  catch(vpException e) {
    std::cout << "Catch an exception: " << e << std::endl;
  }
}

Important remark

To provide high-performance access there is no verification to ensure that 0 $\le$ i < height and 0 $\le$ j < width. Since the memory allocated in the bitmap array is continuous, that means that if (i, j) is outside the image you will manipulate a pixel that is not as expected. To highlight this remark, we provide hereafter an example where the considered pixel is outside the image:

unsigned int width = 320;
unsigned int height = 240;
vpImage<unsigned char> I(height, width); // Create an 320x240 image
// Set pixel coordinates that is outside the image
unsigned int i = 100;
unsigned int j = 400;
unsigned char value;
value = I[i][j]; // Here we will get the pixel value at position (101, 80)

Definition at line 115 of file vpImage.h.

Constructor & Destructor Documentation

template<class Type >

vpImage< Type >::vpImage ( )

constructor

Constructor.

No memory allocation is done

set all the element of the bitmap to value

See also: vpImage::resize(height, width) for memory allocation

Definition at line 509 of file vpImage.h.

template<class Type>

vpImage< Type >::vpImage ( const vpImage< Type > & I )

copy constructor

Copy constructor

Definition at line 634 of file vpImage.h.

References vpImage< Type >::bitmap, vpImage< Type >::getHeight(), vpImage< Type >::getWidth(), vpImage< Type >::resize(), and vpERROR_TRACE.

template<class Type>

vpImage< Type >::vpImage	(	unsigned int	h,
		unsigned int	w
	)

constructor set the size of the image

Constructor.

Allocate memory for an [h x w] image.

Parameters

w	: Image width.
h	: Image height.

Element of the bitmap are set to zero.

If the image has been already initialized, memory allocation is done only if the new image size is different, else we re-use the same memory space.

Exceptions

vpException::memoryAllocationError

See also: vpImage::init(height, width)

Definition at line 454 of file vpImage.h.

References vpImage< Type >::init().

template<class Type>

vpImage< Type >::vpImage	(	unsigned int	h,
		unsigned int	w,
		Type	value
	)

constructor set the size of the image and init all the pixel

Constructor.

Allocate memory for an [height x width] image.

Parameters

w	: Image width.
h	: Image height.
value	: Set all the element of the bitmap to value.

If the image has been already initialized, memory allocation is done only if the new image size is different, else we re-use the same memory space.

Returns: MEMORY_FAULT if memory allocation is impossible, else OK

See also: vpImage::init(height, width, value)

Definition at line 485 of file vpImage.h.

References vpImage< Type >::init(), and vpERROR_TRACE.

template<class Type >

vpImage< Type >::~vpImage ( )

virtual

destructor

Destructor : Memory de-allocation.

Warning: does not deallocate memory for display and video

Definition at line 623 of file vpImage.h.

Member Function Documentation

template<class Type >

void vpImage< Type >::destroy ( )

destructor

Destructor : Memory de-allocation.

Warning: does not deallocate memory for display and video

Definition at line 592 of file vpImage.h.

Referenced by vpImageFilter::filter(), vpImageFilter::gaussianBlur(), and vpTemplateTracker::initTracking().

template<class Type>

void vpImage< Type >::doubleSizeImage ( vpImage< Type > & res )

Returns a new image that's double size of the current image. Used (eg. in case of keypoints extraction, we might double size of the image in order to have more keypoints). The double size image is computed by nearest-neighbour interpolation:

A B C
E F G
H I J
where
A C H J are pixels from original image
B E G I are interpolated pixels

Warning: Operator = must be defined for Type.

Parameters

res	[out] : Image that is double size of the current image.

The example below shows how to use this method:

vpImage<unsigned char> I; // original image
vpImageIo::read(I, "myImage.pgm");
vpImage<unsigned char> I2; // double size image
I.doubleSizeImage(I2);
vpImageIo::write(I2, "myDoubleSizeImage.pgm");

See halfSizeImage(vpImage<Type> &) for an example of pyramid construction.

Definition at line 1017 of file vpImage.h.

References vpImage< Type >::resize().

template<class Type>

void vpImage< Type >::doubleSizeImage ( vpImage< Type > * res )

Deprecated:: This method is deprecated. You should use doubleSizeImage(vpImage<Type> &) instead.

Returns a new image that's double size of the current image. Used (eg. in case of keypoints extraction, we might double size of the image in order to have more keypoints)

Warning: Operator = must be defined for Type.

Exceptions

vpException::memoryAllocationError If images pointer is NULL or if the images size differ.

Definition at line 1558 of file vpImage.h.

References vpImage< Type >::getHeight(), vpImage< Type >::getWidth(), vpException::memoryAllocationError, and vpImage< Type >::resize().

template<class Type>

unsigned int vpImage< Type >::getCols ( ) const

inline

Get the number of columns in the image.

Returns: The image number of column, or image width.

See also: getWidth()

Definition at line 180 of file vpImage.h.

Referenced by vpImageConvert::convert(), vpMomentObject::fromImage(), and vpMbKltTracker::reinit().

template<class Type>

unsigned int vpImage< Type >::getHeight ( ) const

inline

Get the image height.

Returns: The image height.

See also: getWidth()

Definition at line 152 of file vpImage.h.

Referenced by vpDiskGrabber::acquire(), vp1394CMUGrabber::acquire(), vpV4l2Grabber::acquire(), vp1394TwoGrabber::acquire(), vpImageTools::binarise(), vpPlanarObjectDetector::buildReference(), vpKeyPointSurf::buildReference(), vpFernClassifier::buildReference(), vpHistogram::calculate(), vpImageTools::changeLUT(), vpMbtDistanceLine::closeToImageBorder(), vpMeLine::computeRhoTheta(), vpImageConvert::convert(), vpMeSite::convolution(), vpKeyPoint::createImageMatching(), vpImageTools::createSubImage(), vp1394TwoGrabber::dequeue(), vpDetectorDataMatrixCode::detect(), vpDetectorQRCode::detect(), vpImageMorphology::dilatation(), vpMbtDistanceLine::display(), vpMeLine::display(), vpMbKltTracker::display(), vpWireFrameSimulator::display_scene(), vpDisplayX::displayImage(), vpDisplayOpenCV::displayImage(), vpDisplayOpenCV::displayImageROI(), vpFeatureDisplay::displayLine(), vpKeyPoint::displayMatching(), vpDisplay::displayROI(), vpImage< Type >::doubleSizeImage(), vpImageMorphology::erosion(), vpTemplateTrackerZone::fillTriangle(), vpImageFilter::filter(), vpImageFilter::filterX(), vpImageFilter::filterY(), vpImageFilter::filterYBottomBorder(), vpImageTools::flip(), vpViper650::getCameraParameters(), vpViper850::getCameraParameters(), vpAfma6::getCameraParameters(), vpSimulatorAfma6::getCameraParameters(), vpSimulatorViper850::getCameraParameters(), vpTemplateTrackerSSD::getCost(), vpTemplateTrackerZNCC::getCost(), vpKinect::getDepthMap(), vpRobotWireFrameSimulator::getExternalCameraParameters(), vpWireFrameSimulator::getExternalCameraParameters(), vpSimulatorAfma6::getExternalImage(), vpSimulatorViper850::getExternalImage(), vpWireFrameSimulator::getExternalImage(), vpImageFilter::getGaussPyramidal(), vpImageFilter::getGaussXPyramidal(), vpImageFilter::getGaussYPyramidal(), vpImageFilter::getGradX(), vpImageFilter::getGradY(), vpDisplayX::getImage(), vpImageSimulator::getImage(), vpWireFrameSimulator::getInternalCameraParameters(), vpWireFrameSimulator::getInternalImage(), vpRobotWireFrameSimulator::getInternalView(), vpMbtPolygon::getNbCornerInsideImage(), vpAROgre::getRenderingOutput(), vpTemplateTrackerSSD::getSSD(), vpImage< Type >::halfSizeImage(), vpImageTools::imageDifference(), vpImageTools::imageDifferenceAbsolute(), vpDisplayWin32::init(), vpAROgre::init(), vpDisplayX::init(), vpDisplayGTK::init(), vpDisplayOpenCV::init(), vpMbKltTracker::init(), vpMbEdgeTracker::init(), vpTemplateTrackerZone::initFromPoints(), vpTemplateTrackerZNCCForwardAdditional::initHessienDesired(), vpTemplateTrackerZNCCInverseCompositional::initHessienDesired(), vpMbtDistanceLine::initMovingEdge(), vpMbEdgeTracker::initPyramid(), vpTemplateTracker::initTracking(), vpImage< Type >::insert(), vpKeyPoint::insertImageMatching(), vpMbtPolygon::isVisible(), vpMeNurbs::localReSample(), vpPlanarObjectDetector::matchPoint(), vpKeyPointSurf::matchPoint(), vpFernClassifier::matchPoint(), vpWireFrameSimulator::navigation(), vpDiskGrabber::open(), vpVideoWriter::open(), vpVideoReader::open(), vpImage< Type >::operator!=(), vpImage< Type >::operator==(), vpImage< Type >::quarterSizeImage(), vpImageIo::readJPEG(), vpImageIo::readPFM(), vpImageIo::readPGM(), vpImageIo::readPNG(), vpImageIo::readPPM(), vpMbKltTracker::reinit(), vpMbtPolygon::roiInsideImage(), vpMeLine::sample(), vpMeNurbs::sample(), vpDot2::searchDotsInArea(), vpMeNurbs::seekExtremities(), vpMeLine::seekExtremities(), vpMeNurbs::seekExtremitiesCanny(), vpAR::setImage(), vpFernClassifier::setImage(), vpImageConvert::split(), vpImage< Type >::sub(), vpTemplateTrackerZNCCForwardAdditional::trackNoPyr(), vpTemplateTrackerSSDForwardCompositional::trackNoPyr(), vpTemplateTrackerSSDESM::trackNoPyr(), vpTemplateTrackerZNCCInverseCompositional::trackNoPyr(), vpTemplateTrackerSSDInverseCompositional::trackNoPyr(), vpTemplateTrackerSSDForwardAdditional::trackNoPyr(), vpImageTools::undistort(), vpMbtDistanceLine::updateMovingEdge(), vpImage< Type >::vpImage(), vpKinect::warpRGBFrame(), vpImageIo::writeJPEG(), vpImageIo::writePFM(), vpImageIo::writePGM(), vpImageIo::writePNG(), and vpImageIo::writePPM().

template<class Type >

Type vpImage< Type >::getMaxValue ( ) const

Return the maximum value within the bitmap.

See also: getMinValue()

Definition at line 656 of file vpImage.h.

template<class Type>

void vpImage< Type >::getMinMaxValue	(	Type &	min,
		Type &	max
	)		const

Look for the minimum and the maximum value within the bitmap.

See also: getMaxValue(); getMinValue()

Definition at line 688 of file vpImage.h.

Referenced by vpImageConvert::convert().

template<class Type >

Type vpImage< Type >::getMinValue ( ) const

Return the minimum value within the bitmap.

See also: getMaxValue()

Definition at line 672 of file vpImage.h.

template<class Type>

unsigned int vpImage< Type >::getNumberOfPixel ( ) const

inline

Get the image number of pixels which corresponds to the image width multiplied by the image height.

Returns: The image number of pixels or image size.

See also: getWidth(), getHeight()

Definition at line 214 of file vpImage.h.

Referenced by vpImageConvert::split().

template<class Type>

unsigned int vpImage< Type >::getRows ( ) const

inline

Get the number of rows in the image.

Returns: The image number of rows, or image height.

See also: getHeight()

Definition at line 171 of file vpImage.h.

Referenced by vpImageConvert::convert(), vpMomentObject::fromImage(), and vpMbKltTracker::reinit().

template<class Type>

unsigned int vpImage< Type >::getSize ( ) const

inline

Get the image size.

Returns: The image size = width * height.

See also: getWidth(), getHeight()

Definition at line 189 of file vpImage.h.

Referenced by vp1394CMUGrabber::acquire().

template<class Type >

Type vpImage< Type >::getValue	(	double	i,
		double	j
	)		const

Warning: This generic method is not implemented. You should rather use the instantiated methods for double, unsigned char and vpRGBa images.

See also: vpImage<double>::getValue(double, double); vpImage<unsigned char>::getValue(double, double); vpImage<vpRGBa>::getValue(double, double)

Definition at line 1068 of file vpImage.h.

References vpTRACE.

Referenced by vpTemplateTrackerSSD::getCost(), vpTemplateTrackerZNCC::getCost(), vpTemplateTrackerSSD::getSSD(), vpTemplateTrackerZNCCForwardAdditional::initHessienDesired(), vpTemplateTrackerZNCCInverseCompositional::initHessienDesired(), vpTemplateTrackerZNCCForwardAdditional::trackNoPyr(), vpTemplateTrackerSSDForwardCompositional::trackNoPyr(), vpTemplateTrackerSSDESM::trackNoPyr(), vpTemplateTrackerZNCCInverseCompositional::trackNoPyr(), vpTemplateTrackerSSDInverseCompositional::trackNoPyr(), and vpTemplateTrackerSSDForwardAdditional::trackNoPyr().

template<class Type >

Type vpImage< Type >::getValue ( vpImagePoint & ip ) const

Warning: This generic method is not implemented. You should rather use the instantiated methods for double, unsigned char and vpRGBa images.

See also: vpImage<double>::getValue(vpImagePoint &); vpImage<unsigned char>::getValue(vpImagePoint &); vpImage<vpRGBa>::getValue(vpImagePoint &)

Definition at line 1233 of file vpImage.h.

References vpTRACE.

template<class Type>

unsigned int vpImage< Type >::getWidth ( ) const

inline

Get the image width.

Returns: The image width.

See also: getHeight()

Definition at line 161 of file vpImage.h.

template<class Type>

void vpImage< Type >::halfSizeImage ( vpImage< Type > & res )

Returns a new image that's half size of the current image. No filtering is used during the sub sampling.

Used for building pyramid of the image.

Warning: Operator = must be defined for Type.

Parameters

res	[out] : Subsampled image that is half size of the current image.

The example below shows how to use this method:

vpImage<unsigned char> I; // original image
vpImageIo::read(I, "myImage.pgm");
vpImage<unsigned char> I2; // half size image
I.halfSizeImage(I2);
vpImageIo::write(I2, "myHalfSizeImage.pgm");

This other example shows how to construct a pyramid of the image:

vpImage<unsigned char> I[4];   // pyramid with 4 levels
vpImageIo::read(I[1], "myImage.pgm"); // Original image at level 1
// compute the other levels
I5[1].doubleSizeImage(I5[0]);  // double size image at level 0
I5[1].halfSizeImage(I5[2]);    // half size image at level 2
I5[1].quarterSizeImage(I5[3]); // quarter size image at level 3

Definition at line 938 of file vpImage.h.

References vpImage< Type >::resize().

template<class Type>

void vpImage< Type >::halfSizeImage ( vpImage< Type > * res )

Deprecated:: This method is deprecated. You should use halfSizeImage(vpImage<Type> &) instead.

Returns a new image that's half size of the current image. No filtering is used during the sub sampling. Used for building pyramid of the image.

Warning: Operator = must be defined for Type.

Exceptions

vpException::memoryAllocationError If images pointer is NULL or if the images size differ.

Definition at line 1502 of file vpImage.h.

References vpImage< Type >::getHeight(), vpImage< Type >::getWidth(), vpException::memoryAllocationError, and vpImage< Type >::resize().

template<class Type >

void vpImage< Type >::init	(	unsigned int	h,
		unsigned int	w
	)

set the size of the image

Image initialization.

Allocate memory for an [h x w] image.

Parameters

w	: Image width.
h	: Image height.

Element of the bitmap are not initialized

If the image has been already initialized, memory allocation is done only if the new image size is different, else we re-use the same memory space.

Exceptions

vpException::memoryAllocationError

Definition at line 386 of file vpImage.h.

References vpException::memoryAllocationError, vpDEBUG_TRACE, and vpERROR_TRACE.

Referenced by vpPlot::init(), and vpImage< Type >::vpImage().

template<class Type>

void vpImage< Type >::init	(	unsigned int	h,
		unsigned int	w,
		Type	value
	)

set the size of the image

Image initialisation.

Allocate memory for an [h x w] image.

Parameters

w	: Image width.
h	: Image height.
value	: Set all the element of the bitmap to value.

Exceptions

vpException::memoryAllocationError

See also: vpImage::init(h, w)

Definition at line 350 of file vpImage.h.

References vpERROR_TRACE.

template<class Type>

void vpImage< Type >::insert	(	const vpImage< Type > &	src,
		const vpImagePoint	topLeft
	)

Insert an image into another one.

It is possible to insert the image $ src $ into the calling vpImage. You can set the point in the destination image where the top left corner of the $ src $ image will belocated.

Parameters

src	: Image to insert
topLeft	: Coordinates of the image's top left corner in the destination image.

Definition at line 855 of file vpImage.h.

References vpImage< Type >::bitmap, vpImagePoint::get_i(), vpImagePoint::get_j(), vpImage< Type >::getHeight(), and vpImage< Type >::getWidth().

Referenced by vpKeyPoint::insertImageMatching().

template<class Type>

bool vpImage< Type >::operator!= ( const vpImage< Type > & I )

Compare two images.

Returns: true if the images are different, false if they are the same.

Definition at line 797 of file vpImage.h.

References vpImage< Type >::bitmap, vpImage< Type >::getHeight(), and vpImage< Type >::getWidth().

template<class Type>

Type vpImage< Type >::operator()	(	const unsigned int	i,
		const unsigned int	j
	)		const

inline

Get the value of an image point.

Parameters

i,j	: Image point coordinates; i for the row position, j for the column position.

Returns: Value of the image point (i, j).

Definition at line 237 of file vpImage.h.

template<class Type>

void vpImage< Type >::operator()	(	const unsigned int	i,
		const unsigned int	j,
		const Type &	v
	)

inline

Set the value of an image point.

Parameters

i,j	Image point coordinates; i for the row position, j for the column position.
v	: Value to set for image point (i, j).

Definition at line 250 of file vpImage.h.

template<class Type>

Type vpImage< Type >::operator() ( const vpImagePoint & ip ) const

inline

Get the value of an image point.

Parameters

ip	: An image point with sub-pixel coordinates. Sub-pixel coordinates are roughly transformed to insigned int coordinates by cast.

Returns: Value of the image point ip.

See also: getValue(const vpImagePoint &)

Definition at line 266 of file vpImage.h.

template<class Type>

void vpImage< Type >::operator()	(	const vpImagePoint &	ip,
		const Type &	v
	)

inline

Set the value of an image point.

Parameters

ip	: An image point with sub-pixel coordinates. Sub-pixel coordinates are roughly transformed to insigned int coordinates by cast.
v	: Value to set for the image point.

Definition at line 282 of file vpImage.h.

template<class Type>

vpImage< Type > vpImage< Type >::operator- ( const vpImage< Type > & B )

Operation A - B (A is unchanged).

#include <visp/vpImage.h>
int main()
{
  vpImage<unsigned char> A(288, 384);
  vpImage<unsigned char> B(288, 384);
  vpImage<unsigned char> C;
  A = 128;
  B = 120;
  // operator-() : C = A - B
  C = A - B;
  return 0;
}

See also: sub(const vpImage<Type> &, const vpImage<Type> &, vpImage<Type> &) to avoid matrix allocation for each use.

Definition at line 838 of file vpImage.h.

template<class Type>

vpImage< Type > & vpImage< Type >::operator= ( const vpImage< Type > & I )

Copy operator.

Definition at line 702 of file vpImage.h.

References vpImage< Type >::bitmap, vpException::memoryAllocationError, and vpERROR_TRACE.

template<class Type>

vpImage< Type > & vpImage< Type >::operator= ( const Type & v )

= operator : Set all the element of the bitmap to a given value v. $ A = v <=> A[i][j] = v $

Warning: = must be defined for Type

Definition at line 763 of file vpImage.h.

template<class Type>

bool vpImage< Type >::operator== ( const vpImage< Type > & I )

Compare two images.

Returns: true if the images are the same, false otherwise.

Definition at line 777 of file vpImage.h.

References vpImage< Type >::bitmap, vpImage< Type >::getHeight(), and vpImage< Type >::getWidth().

template<class Type>

Type* vpImage< Type >::operator[] ( const unsigned int i )

inline

operator[] allows operation like I[i] = x.

Definition at line 221 of file vpImage.h.

template<class Type>

Type* vpImage< Type >::operator[] ( const int i )

inline

Definition at line 222 of file vpImage.h.

template<class Type>

const Type* vpImage< Type >::operator[] ( unsigned int i ) const

inline

operator[] allows operation like x = I[i]

Definition at line 225 of file vpImage.h.

template<class Type>

const Type* vpImage< Type >::operator[] ( int i ) const

inline

Definition at line 226 of file vpImage.h.

template<class Type>

void vpImage< Type >::quarterSizeImage ( vpImage< Type > & res )

Returns a new image that's a quarter size of the current image. No filtering is used during the sub sampling. Used for building a quarter of the image.

Warning: Operator = must be defined for Type.

Parameters

res	[out] : Subsampled image that is quarter size of the current image.

The example below shows how to use this method:

vpImage<unsigned char> I; // original image
vpImageIo::read(I, "myImage.pgm");
vpImage<unsigned char> I4; // quarter size image
I.halfSizeImage(I4);
vpImageIo::write(I4, "myQuarterSizeImage.pgm");

See halfSizeImage(vpImage<Type> &) for an example of pyramid construction.

Definition at line 972 of file vpImage.h.

References vpImage< Type >::resize().

template<class Type>

void vpImage< Type >::quarterSizeImage ( vpImage< Type > * res )

Deprecated:: This method is deprecated. You should use quarterSizeImage(vpImage<Type> &) instead.

Returns a new image that's a quarter size of the current image. Used for building a quarter of the image.

Warning: Operator = must be defined for Type.

Exceptions

vpException::memoryAllocationError If images pointer is NULL or if the images size differ.

Definition at line 1530 of file vpImage.h.

References vpImage< Type >::getHeight(), vpImage< Type >::getWidth(), vpException::memoryAllocationError, and vpImage< Type >::resize().

template<class Type >

void vpImage< Type >::resize	(	const unsigned int	h,
		const unsigned int	w
	)

set the size of the image without initializing it.

resize the image : Image initialization

Allocate memory for an [height x width] image.

Warning: The image is not initialized.

Parameters

w	: Image width.
h	: Image height.

Element of the bitmap are not initialized

If the image has been already initialized, memory allocation is done only if the new image size is different, else we re-use the same memory space.

Exceptions

vpException::memoryAllocationError

See also: init(unsigned int, unsigned int)

Definition at line 536 of file vpImage.h.

References vpERROR_TRACE.

Referenced by vpV4l2Grabber::acquire(), vp1394TwoGrabber::acquire(), vpImageConvert::convert(), vpImageTools::createSubImage(), vp1394TwoGrabber::dequeue(), vpImage< Type >::doubleSizeImage(), vpImageFilter::filter(), vpImageFilter::filterX(), vpImageFilter::filterY(), vpImageTools::flip(), vpImageFilter::getGaussXPyramidal(), vpImageFilter::getGaussYPyramidal(), vpImageFilter::getGradX(), vpImageFilter::getGradY(), vpDisplayX::getImage(), vpDisplayGTK::getImage(), vpSimulator::getInternalImage(), vpAROgre::getRenderingOutput(), vpImage< Type >::halfSizeImage(), vpImageTools::imageDifference(), vpImageTools::imageDifferenceAbsolute(), vpProjectionDisplay::init(), vpV4l2Grabber::open(), vp1394CMUGrabber::open(), vpImage< Type >::quarterSizeImage(), vpImageIo::readJPEG(), vpImageIo::readPFM(), vpImageIo::readPGM(), vpImageIo::readPNG(), vpImageIo::readPPM(), vpImageConvert::split(), vpImage< Type >::sub(), vpImageTools::undistort(), vpImage< Type >::vpImage(), vpKinect::vpKinect(), vpRobotWireFrameSimulator::vpRobotWireFrameSimulator(), vpKinect::warpRGBFrame(), and vpImageIo::writePGM().

template<class Type>

void vpImage< Type >::resize	(	const unsigned int	h,
		const unsigned int	w,
		const Type	val
	)

set the size of the image and initialize it.

resize the image : Image initialization

Allocate memory for an [height x width] image and initialize the image.

Parameters

w	: Image width.
h	: Image height.
val	: Pixels value.

Element of the bitmap are not initialized

If the image has been already initialized, memory allocation is done only if the new image size is different, else we re-use the same memory space.

Exceptions

vpException::memoryAllocationError

See also: init(unsigned int, unsigned int)

Definition at line 570 of file vpImage.h.

References vpERROR_TRACE.

template<class Type>

void vpImage< Type >::sub	(	const vpImage< Type > &	B,
		vpImage< Type > &	C
	)

Operation C = *this - B.

#include <visp/vpImage.h>
int main()
{
  vpImage<unsigned char> A(288, 384);
  vpImage<unsigned char> B(288, 384);
  vpImage<unsigned char> C;
  A = 128;
  B = 120;
  A.sub(B, C); // C = A - B
  return 0;
}

The result is placed in the third parameter C and not returned. A new image won't be allocated for every use of the function (Speed gain if used many times with the same result matrix size).

Exceptions

vpException::memoryAllocationError If the images size differ.

See also: operator-()

Definition at line 1383 of file vpImage.h.

References vpImage< Type >::bitmap, vpImage< Type >::getHeight(), vpImage< Type >::getWidth(), vpException::memoryAllocationError, vpImage< Type >::resize(), and vpERROR_TRACE.

template<class Type>

void vpImage< Type >::sub	(	const vpImage< Type > &	A,
		const vpImage< Type > &	B,
		vpImage< Type > &	C
	)

Operation C = A - B.

The result is placed in the third parameter C and not returned. A new image won't be allocated for every use of the function (Speed gain if used many times with the same result matrix size).

Exceptions

vpException::memoryAllocationError If the images size differ.