Transform Struct Reference

Image Processing Transforms. More...

#include <Transforms.h>

Public Member Functions
std::string	getDescription () const
	Get description of processing engine.
void	normalize (RawTile &in, const std::vector< float > &max, const std::vector< float > &min)
	Function to create normalized array.
void	cmap (RawTile &in, enum cmap_type cmap)
	Function to apply colormap to gray images.
void	inv (RawTile &in)
	Function to invert colormaps.
void	shade (RawTile &in, int h_angle, int v_angle)
	Hillshading function to simulate raking light images.
void	LAB2sRGB (RawTile &in)
	Convert from CIELAB to sRGB colour space.
void	scale_to_8bit (RawTile &in)
	Fast efficient scaling from higher fixed point bit depths to 8 bit.
void	contrast (RawTile &in, float c)
	Function to apply a contrast adjustment and clip to 8 bit.
void	gamma (RawTile &in, float g)
	Apply a gamma correction (exponential transform)
void	log (RawTile &in)
	Apply log transform: out = c log( 1 + in )
void	interpolate_nearestneighbour (RawTile &in, unsigned int w, unsigned int h)
	Resize image using nearest neighbour interpolation.
void	interpolate_bilinear (RawTile &in, unsigned int w, unsigned int h)
	Resize image using bilinear interpolation.
void	rotate (RawTile &in, float angle)
	Rotate image - currently only by 90, 180 or 270 degrees, other values will do nothing.
void	greyscale (RawTile &in)
	Convert image to grayscale.
void	twist (RawTile &in, const std::vector< std::vector< float > > &ctw)
	Apply a color twist.
void	flatten (RawTile &in, int bands)
	Extract bands.
void	flip (RawTile &in, int o)
	Flip image.
std::vector< unsigned int >	histogram (RawTile &in, const std::vector< float > &max, const std::vector< float > &min)
	Calculate histogram of an image.
unsigned char	threshold (std::vector< unsigned int > &histogram)
	Calculate threshold for binary (bi-level) segmentation.
void	binary (RawTile &in, unsigned char threshold)
	Create binary (bi-level) image.
void	equalize (RawTile &in, std::vector< unsigned int > &histogram)
	Apply histogram equalization to an image.
void	convolution (RawTile &in, const std::vector< float > &conv)
	Apply convolution.

Detailed Description

Image Processing Transforms.

Member Function Documentation

binary()

void Transform::binary	(	RawTile &	in,
		unsigned char	threshold
	)

Create binary (bi-level) image.

Parameters

in	input image
threshold	threshold for binary image segmentation

cmap()

void Transform::cmap	(	RawTile &	in,
		enum cmap_type	cmap
	)

Function to apply colormap to gray images.

Parameters

in	tile data to be converted
cmap	color map to apply.

contrast()

void Transform::contrast	(	RawTile &	in,
		float	c
	)

Function to apply a contrast adjustment and clip to 8 bit.

Parameters

in	tile data to be adjusted
c	contrast value

convolution()

void Transform::convolution	(	RawTile &	in,
		const std::vector< float > &	conv
	)

Apply convolution.

Parameters

in	input image
conv	convolution matrix

equalize()

void Transform::equalize	(	RawTile &	in,
		std::vector< unsigned int > &	histogram
	)

Apply histogram equalization to an image.

Parameters

in	input image
histogram	image histogram

flatten()

void Transform::flatten	(	RawTile &	in,
		int	bands
	)

Extract bands.

Parameters

in	input image
bands	number of bands

flip()

void Transform::flip	(	RawTile &	in,
		int	o
	)

Flip image.

Parameters

in	input image
o	orientation (0=horizontal,1=vertical)

gamma()

void Transform::gamma	(	RawTile &	in,
		float	g
	)

Apply a gamma correction (exponential transform)

Parameters

in	tile input data
g	gamma

greyscale()

void Transform::greyscale

(

RawTile &

in

)

Convert image to grayscale.

Parameters

in	input image

histogram()

std::vector< unsigned int > Transform::histogram	(	RawTile &	in,
		const std::vector< float > &	max,
		const std::vector< float > &	min
	)

Calculate histogram of an image.

Parameters

in	input image
max	max image values for each channel
min	min image values for each channel

Returns

vector containing histogram (single histogram for all channels)

interpolate_bilinear()

void Transform::interpolate_bilinear	(	RawTile &	in,
		unsigned int	w,
		unsigned int	h
	)

Resize image using bilinear interpolation.

Parameters

in	tile input data
w	target width
h	target height

interpolate_nearestneighbour()

void Transform::interpolate_nearestneighbour	(	RawTile &	in,
		unsigned int	w,
		unsigned int	h
	)

Resize image using nearest neighbour interpolation.

Parameters

in	tile input data
w	target width
h	target height

inv()

void Transform::inv

(

RawTile &

in

)

Function to invert colormaps.

Parameters

in	tile data to be adjusted

LAB2sRGB()

void Transform::LAB2sRGB

(

RawTile &

in

)

Convert from CIELAB to sRGB colour space.

Parameters

in	tile data to be converted

log()

void Transform::log

(

RawTile &

in

)

Apply log transform: out = c log( 1 + in )

Parameters

in	input image

normalize()

void Transform::normalize	(	RawTile &	in,
		const std::vector< float > &	max,
		const std::vector< float > &	min
	)

Function to create normalized array.

Parameters

in	tile data to be adjusted
min	: vector of minima
max	: vector of maxima

rotate()

void Transform::rotate	(	RawTile &	in,
		float	angle
	)

Rotate image - currently only by 90, 180 or 270 degrees, other values will do nothing.

Parameters

in	tile input data
angle	angle of rotation - currently only rotations by 90, 180 and 270 degrees are suported, for other values, no rotation will occur

scale_to_8bit()

void Transform::scale_to_8bit

(

RawTile &

in

)

Fast efficient scaling from higher fixed point bit depths to 8 bit.

Parameters

in	tile data to be converted

shade()

void Transform::shade	(	RawTile &	in,
		int	h_angle,
		int	v_angle
	)

Hillshading function to simulate raking light images.

Parameters

in	tile input data containing normal vectors at each point
h_angle	angle in the horizontal plane from 12 o'clock in degrees
v_angle	angle in the vertical plane in degrees. 0 is flat, 90 pointing directly down.

threshold()

unsigned char Transform::threshold

(

std::vector< unsigned int > &

histogram

)

Calculate threshold for binary (bi-level) segmentation.

Parameters

histogram

image histogram

Returns

threshold

twist()

void Transform::twist	(	RawTile &	in,
		const std::vector< std::vector< float > > &	ctw
	)

Apply a color twist.

Parameters

in	input image
ctw	2D color twist matrix

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The documentation for this struct was generated from the following file:

• Transforms.h