avir::CImageResizerFilterStepINL< fptype, fptypeatom > Class Template Reference

Interleaved filtering steps implementation class. More...

#include <avir.h>

Inheritance diagram for avir::CImageResizerFilterStepINL< fptype, fptypeatom >:

Public Member Functions
void	convertVtoH (const fptype *ip, fptype *op, const int SrcLen, const int SrcIncr) const
	Converts vertical scanline to horizontal scanline.
void	doFilter (const fptype *const Src, fptype *Dst, const int DstIncr) const
	Performs scanline filtering with optional downsampling.
void	doResize (const fptype *SrcLine, fptype *DstLine, const int DstLineIncr, fptype *const) const
	Performs resizing of a single scanline.
void	doResize2 (const fptype *SrcLine, fptype *DstLine, const int DstLineIncr, fptype *const) const
	Performs resizing of a single scanline assuming that the input buffer consists of zero-padded elements (2X upsampling without filtering).
void	doUpsample (const fptype *const Src, fptype *const Dst) const
	Performs scanline upsampling with filtering.
template<typename Tin>
void	packScanline (const Tin *ip, fptype *const op0, const int l0) const
	Performs "packing" of a scanline, and type conversion.
void	prepareInBuf (fptype *Src) const
	Prepares input scanline buffer for this filtering step.

Static Public Member Functions
static void	applySRGBGamma (fptype *p, int l, const CImageResizerVars &Vars0)
	Applies Linear to sRGB gamma correction to the specified scanline.
template<typename Tout>
static void	unpackScanline (const fptype *ip, Tout *op, int l, const CImageResizerVars &Vars0)
	Performs "unpacking" of a scanline, and type conversion.

Additional Inherited Members
Public Attributes inherited from avir::CImageResizerFilterStep< fptype, fptypeatom >
double	DCGain
	DC gain which was applied to the filter. Not defined, if ResampleFactor equals 0.
int	EdgePixelCount
	The number of edge pixels added. Affects the initial position within the input scanline, used to produce edge pixels. This variable is used and should be defined when IsUpsample equals false and ResampleFactor is greater than 0. When assigning this variable, it is also necessary to update InPrefix, OutLen, and Vars.o variables.
CBuffer< fptype >	Flt
	Filter to use at this step.
const CDSPFracFilterBankLin< fptype > *	FltBank
	Filter bank in use by this resizing step, may be equal to FltBankDyn.
CDSPFracFilterBankLin< fptype > *	FltBankDyn
	Dynamically-allocated filter bank in use by this resizing step. Equals nullptr, if a static FltBank filter bank is in use.
int	FltLatency
	Filter's latency (group delay, shift) in pixels.
CFltBuffer	FltOrig
	Originally-designed filter. This buffer may not be assigned. Assigned by filters that precede the resizing step if such filter is planned to be embedded into the interpolation filter as "external" filter. If IsUpsample equals true, and this filter buffer is not empty, the upsampling step will not itself apply any filtering over upsampled input scanline.
int	InBuf
	Input buffer index, 0 or 1.
int	InElIncr
	Pixel element increment within the input buffer, used during de-interleaved processing: in this case each image's channel is stored independently, InElIncr elements apart.
int	InLen
	Input scanline's length in pixels.
int	InPrefix
	Required input prefix pixels. These prefix pixels will be filled with source scanline's first pixel value. If IsUpsample is true, this is the additional number of times the first pixel will be filtered before processing scanline, this number is also reflected in the OutPrefix.
int	InSuffix
	Required input suffix pixels. These suffix pixels will be filled with source scanline's last pixel value. If IsUpsample is true, this is the additional number of times the last pixel will be filtered before processing scanline, this number is also reflected in the OutSuffix.
bool	IsUpsample
	true, if this step is an upsampling step; false, if downsampling step. Should be set to false, if ResampleFactor equals 0.
int	OutBuf
	Output buffer index. 0 or 1; 2 for the last step.
int	OutElIncr
	Pixel element increment within the output buffer, used during de-interleaved processing. Equals to InBufElIncr of the next step.
int	OutLen
	Length of the resulting scanline.
int	OutPrefix
	Required output prefix pixels. These prefix pixels will not be pre-filled with any values. Value is valid only if IsUpsample equals true.
int	OutSuffix
	Required input suffix pixels. These suffix pixels will not be pre-filled with any values. Value is valid only if IsUpsample equals true.
CBuffer< fptype >	PrefixDC
	DC component fluctuations added at the start of the resulting scanline, used when IsUpsample equals true.
int	ResampleFactor
	Resample factor (greater or equal to 1). If 0, this is a resizing step. This value should be greater than 1, if IsUpsample equals true.
CRPosBuf *	RPosBuf
	Resizing positions buffer. Used when ResampleFactor equals 0 (resizing step).
CBuffer< fptype >	SuffixDC
	DC component fluctuations added at the end of the resulting scanline, used when IsUpsample equals true.
const CImageResizerVars *	Vars
	Image resizing-related variables.
Static Public Attributes inherited from avir::CImageResizerFilterStep< fptype, fptypeatom >
static const int	EdgePixelCountDef = 3
	The default number of pixels additionally produced at scanline edges during filtering. This is required to reduce edge artifacts.

Detailed Description

template<typename fptype, typename fptypeatom>
class avir::CImageResizerFilterStepINL< fptype, fptypeatom >

Interleaved filtering steps implementation class.

This class implements scanline filtering functions in interleaved mode. This means that each pixel is processed independently, not in groups.

Template Parameters

fptype	Floating point type to use for storing pixel elements. SIMD types can be used: in this case each element may hold a whole pixel.
fptypeatom	The atomic type the fptype consists of.

Member Function Documentation

applySRGBGamma()

template<typename fptype, typename fptypeatom>

static void avir::CImageResizerFilterStepINL< fptype, fptypeatom >::applySRGBGamma ( fptype * p, int l, const CImageResizerVars & Vars0 )

static

Applies Linear to sRGB gamma correction to the specified scanline.

Parameters

p	Scanline.
l	The number of pixels to de-linearize.
Vars0	Image resizing-related variables.

convertVtoH()

template<typename fptype, typename fptypeatom>

void avir::CImageResizerFilterStepINL< fptype, fptypeatom >::convertVtoH	(	const fptype *	ip,
		fptype *	op,
		const int	SrcLen,
		const int	SrcIncr ) const

Converts vertical scanline to horizontal scanline.

This function is called by the image resizer when image is resized vertically. This means that the vertical scanline is stored in the same format produced by the packScanline() and maintained by other filtering functions.

Parameters

ip	Input vertical scanline.
op	Output buffer (temporary buffer used during resizing).
SrcLen	The number of pixels in the input scanline, also used to calculate input buffer increment.
SrcIncr	Input buffer increment to the next vertical pixel.

doFilter()

template<typename fptype, typename fptypeatom>

void avir::CImageResizerFilterStepINL< fptype, fptypeatom >::doFilter	(	const fptype *const	Src,
		fptype *	Dst,
		const int	DstIncr ) const

Performs scanline filtering with optional downsampling.

Function makes use of the symmetry of the filter.

Parameters

Src	Source scanline buffer (length = InLen). Source scanline increment will be equal to ElCount.
Dst	Destination scanline buffer.
DstIncr	Destination scanline buffer increment, used for horizontal or vertical scanline stepping.

doResize()

template<typename fptype, typename fptypeatom>

void avir::CImageResizerFilterStepINL< fptype, fptypeatom >::doResize	(	const fptype *	SrcLine,
		fptype *	DstLine,
		const int	DstLineIncr,
		fptype * const	) const

Performs resizing of a single scanline.

This function does not "know" about the length of the source scanline buffer. This buffer should be padded with enough pixels so that SrcPos - FilterLenD2 is always greater or equal to 0, and SrcPos + ( DstLineLen - 1 ) * k + FilterLenD2 + 1 does not exceed source scanline's buffer length. SrcLine increment is assumed to be equal to ElCount.

Parameters

SrcLine	Source scanline buffer.
DstLine	Destination (resized) scanline buffer.
DstLineIncr	Destination scanline position increment, used for horizontal or vertical scanline stepping.

doResize2()

template<typename fptype, typename fptypeatom>

void avir::CImageResizerFilterStepINL< fptype, fptypeatom >::doResize2	(	const fptype *	SrcLine,
		fptype *	DstLine,
		const int	DstLineIncr,
		fptype * const	) const

Performs resizing of a single scanline assuming that the input buffer consists of zero-padded elements (2X upsampling without filtering).

Similar to the doResize() function otherwise.

Parameters

SrcLine	Source scanline buffer.
DstLine	Destination (resized) scanline buffer.
DstLineIncr	Destination scanline position increment, used for horizontal or vertical scanline stepping.

doUpsample()

template<typename fptype, typename fptypeatom>

void avir::CImageResizerFilterStepINL< fptype, fptypeatom >::doUpsample	(	const fptype *const	Src,
		fptype *const	Dst ) const

Performs scanline upsampling with filtering.

Parameters

Src	Source scanline buffer (length = InLen). Source scanline increment will be equal to ElCount.
Dst	Destination scanline buffer.

packScanline()

template<typename fptype, typename fptypeatom>

template<typename Tin>

void avir::CImageResizerFilterStepINL< fptype, fptypeatom >::packScanline	(	const Tin *	ip,
		fptype *const	op0,
		const int	l0 ) const

Performs "packing" of a scanline, and type conversion.

Scanline, depending on the fptype can be potentially stored as a packed SIMD values having a certain atomic type. If required, the sRGB gamma correction is applied.

Parameters

ip	Input scanline.
op0	Output scanline.
l0	The number of pixels to "pack".

Template Parameters

Tin	Input values' type.

prepareInBuf()

template<typename fptype, typename fptypeatom>

void avir::CImageResizerFilterStepINL< fptype, fptypeatom >::prepareInBuf

(

fptype *

Src

)

const

Prepares input scanline buffer for this filtering step.

Left- and right-most pixels are replicated to make sure no buffer overrun happens. Such approach also allows to bypass any pointer range checks.

Parameters

Src	Source buffer.

unpackScanline()

template<typename fptype, typename fptypeatom>

template<typename Tout>

static void avir::CImageResizerFilterStepINL< fptype, fptypeatom >::unpackScanline ( const fptype * ip, Tout * op, int l, const CImageResizerVars & Vars0 )

static

Performs "unpacking" of a scanline, and type conversion.

Truncation is used when floating point is converted to integer.

Scanline, depending on the fptype can be potentially stored as a packed SIMD values having a certain atomic type. The unpacking function assumes that scanline is stored in the style produced by the packScanline() function.

Parameters

ip	Input scanline.
op	Output scanline.
l	The number of pixels to "unpack".
Vars0	Image resizing-related variables.

Template Parameters

Tout	Output value's type.