#include <lancir.h>

Classes
class	CResizeFilters

struct	CResizePos

class	CResizeScanline

Public Member Functions
template<class T >
void	resizeImage (const T const SrcBuf, const int SrcWidth, const int SrcHeight, int SrcScanlineSize, T const NewBuf, const int NewWidth, const int NewHeight, const int ElCount, const double kx0=0.0, const double ky0=0.0, double ox=0.0, double oy=0.0)

Static Protected Member Functions
template<class T >
static void	copyOutput1 (const float ip, T op, int l, const int opinc, const bool IsIOFloat, const int Clamp)

template<class T >
static void	copyOutput2 (const float ip, T op, int l, const int opinc, const bool IsIOFloat, const int Clamp)

template<class T >
static void	copyOutput3 (const float ip, T op, int l, const int opinc, const bool IsIOFloat, const int Clamp)

template<class T >
static void	copyOutput4 (const float ip, T op, int l, const int opinc, const bool IsIOFloat, const int Clamp)

template<class T >
static void	copyScanline1h (const T *ip, CResizeScanline &rs, const int l)

template<class T >
static void	copyScanline1v (const T *ip, CResizeScanline &rs, const int l, const int ipinc)

template<class T >
static void	copyScanline2h (const T *ip, CResizeScanline &rs, const int l)

template<class T >
static void	copyScanline2v (const T *ip, CResizeScanline &rs, const int l, const int ipinc)

template<class T >
static void	copyScanline3h (const T *ip, CResizeScanline &rs, const int l)

template<class T >
static void	copyScanline3v (const T *ip, CResizeScanline &rs, const int l, const int ipinc)

template<class T >
static void	copyScanline4h (const T *ip, CResizeScanline &rs, const int l)

template<class T >
static void	copyScanline4v (const T *ip, CResizeScanline &rs, const int l, const int ipinc)

static void	resize1 (float op, int DstLen, CResizePos rp, const int kl)

static void	resize2 (float op, int DstLen, CResizePos rp, const int kl)

static void	resize3 (float op, int DstLen, CResizePos rp, const int kl)

static void	resize4 (float op, int DstLen, CResizePos rp, const int kl)

static int	roundclamp (const float v, const int Clamp)

Protected Attributes
float *	FltBuf

size_t	FltBufLen

CResizeFilters	rfh

CResizeFilters	rfv0

CResizeScanline	rsh

CResizeScanline	rsv

float *	spv

int	spvlen

Detailed Description

LANCIR image resizer class.

The object of this class can be used to resize 1-4 channel images to any required size. Resizing is performed by utilizing Lanczos filters, with 8-bit precision. This class offers a kind of "optimal" Lanczos resampling implementation.

Object of this class can be allocated on stack.

Note that object of this class does not free temporary buffers and variables after the resizeImage() call (until object's destruction), these buffers are reused on subsequent calls making batch resizing of same-size images faster. This means resizing is not thread-safe: a separate object should be created for each thread.

Member Function Documentation

template<class T >

static void avir::CLancIR::copyOutput1	(	const float *	ip,
		T *	op,
		int	l,
		const int	opinc,
		const bool	IsIOFloat,
		const int	Clamp
	)

staticprotected

Function performs final output of the resized scanline data to the destination image buffer. Variants for 1-4-channel image.

Parameters

ip	Input resized scanline.
op	Output image buffer.
l	Pixel count.
opinc	"op" increment, should account ElCount.
IsIOFloat	"True" if float output and no clamping is necessary.
Clamp	Clamp high level, used if IsIOFloat is "false".

template<class T >

static void avir::CLancIR::copyScanline1h	(	const T *	ip,
		CResizeScanline &	rs,
		const int	l
	)

staticprotected

Function copies scanline from the source buffer in its native format to internal scanline buffer, in preparation for horizontal resizing. Variants for 1-4-channel images.

Parameters

ip	Source scanline buffer.
rs	Scanline resizing positions object.
l	Source scanline length, in pixels.
ipinc	"ip" increment per pixel.

template<class T >

static void avir::CLancIR::copyScanline1v	(	const T *	ip,
		CResizeScanline &	rs,
		const int	l,
		const int	ipinc
	)

staticprotected

Function copies scanline from the source buffer in its native format to internal scanline buffer, in preparation for vertical resizing. Variants for 1-4-channel images.

Parameters

ip	Source scanline buffer.
rs	Scanline resizing positions object.
l	Source scanline length, in pixels.
ipinc	"ip" increment per pixel.

static void avir::CLancIR::resize1	(	float *	op,
		int	DstLen,
		CResizePos *	rp,
		const int	kl
	)

staticprotected

Function performs internal scanline resizing. Variants for 1-4-channel images.

Parameters

op	Destination buffer.
DstLen	Destination length, in pixels.
rp	Resizing positions and filters.
kl	Filter kernel length, in taps.

template<class T >

void avir::CLancIR::resizeImage	(	const T *const	SrcBuf,
		const int	SrcWidth,
		const int	SrcHeight,
		int	SrcScanlineSize,
		T *const	NewBuf,
		const int	NewWidth,
		const int	NewHeight,
		const int	ElCount,
		const double	kx0 = `0.0`,
		const double	ky0 = `0.0`,
		double	ox = `0.0`,
		double	oy = `0.0`
	)

Function resizes image.

Parameters

	SrcBuf	Source image buffer.
	SrcWidth	Source image width.
	SrcHeight	Source image height.
	SrcScanlineSize	Physical size of source scanline in elements (not bytes). If this value is below 1, SrcWidth * ElCount will be used as the physical source scanline size.
[out]	NewBuf	Buffer to accept the resized image. Can be equal to SrcBuf if the size of the resized image is smaller or equal to source image in size.
	NewWidth	New image width.
	NewHeight	New image height.
	ElCount	The number of elements (channels) used to store each source and destination pixel (1-4).
	kx0	Resizing step - horizontal (one output pixel corresponds to "k" input pixels). A downsizing factor if > 1.0; upsizing factor if <= 1.0. Multiply by -1 if you would like to bypass "ox" and "oy" adjustment which is done by default to produce a centered image. If step value equals 0, the step value will be chosen automatically.
	ky0	Resizing step - vertical. Same as "kx".
	ox	Start X pixel offset within source image (can be negative). Positive offset moves the image to the left.
	oy	Start Y pixel offset within source image (can be negative). Positive offset moves the image to the top.

Template Parameters

T	Input and output buffer element's type. Can be uint8_t (0-255 value range), uint16_t (0-65535 value range), float (any value range), double (any value range). Larger integer types are treated as uint16_t. Signed integer types are unsupported.

static int avir::CLancIR::roundclamp	(	const float	v,
		const int	Clamp
	)

staticprotected

Function rounds a value and applies clamping.

Parameters

v	Value to round and clamp.
Clamp	High clamp level, low level is 0.

Member Data Documentation

float* avir::CLancIR::FltBuf

protected

Intermediate resizing buffer.

size_t avir::CLancIR::FltBufLen

protected

Intermediate resizing buffer length.

CResizeFilters avir::CLancIR::rfh

protected

Resizing filters for horizontal resizing.

CResizeFilters avir::CLancIR::rfv0

protected

Resizing filters for vertical resizing (may not be in use).

CResizeScanline avir::CLancIR::rsh

protected

Horizontal resize scanline.

CResizeScanline avir::CLancIR::rsv

protected

Vertical resize scanline.

float* avir::CLancIR::spv

protected

Scanline buffer for vertical resizing.

int avir::CLancIR::spvlen

protected

Length of "spv".

Classes

Public Member Functions

Static Protected Member Functions

Protected Attributes

Detailed Description

Member Function Documentation

Member Data Documentation