gabor

Documentation

Overview

package gabor provides a gabor filter for visual and other forms of signal processing

Index

• type Filter
  • func (gf *Filter) Defaults()
  • func (gf *Filter) SetSize(sz, spc int)
  • func (gf *Filter) ToTable(tab *etable.Table)
  • func (gf *Filter) ToTensor(tsr *etensor.Float32)
  • func (gf *Filter) Update()

Types

type Filter

type Filter struct {

	// is this filter active?
	On bool `desc:"is this filter active?"`

	// [viewif: On] how much relative weight does this filter have when combined with other filters
	Wt float32 `viewif:"On" desc:"how much relative weight does this filter have when combined with other filters"`

	// [def: 2] [viewif: On] overall gain multiplier applied after filtering -- only relevant if not using renormalization (otherwize it just gets renormed away)
	Gain float32 `` /* 159-byte string literal not displayed */

	// [viewif: On] size of the overall filter -- number of pixels wide and tall for a square matrix used to encode the filter -- filter is centered within this square -- typically an even number, min effective size ~6
	Size int `` /* 217-byte string literal not displayed */

	// [viewif: On] wavelength of the sine waves -- number of pixels over which a full period of the wave takes place -- typically same as Size (computation adds a 2 PI factor to translate into pixels instead of radians)
	WvLen float32 `` /* 219-byte string literal not displayed */

	// [viewif: On] how far apart to space the centers of the gabor filters -- 1 = every pixel, 2 = every other pixel, etc -- high-res should be 1 or 2, lower res can be increments therefrom
	Spacing int `` /* 189-byte string literal not displayed */

	// [def: 0.3] [viewif: On] gaussian sigma for the length dimension (elongated axis perpendicular to the sine waves) -- as a normalized proportion of filter Size
	SigLen float32 `` /* 162-byte string literal not displayed */

	// [def: 0.15,0.2] [viewif: On] gaussian sigma for the width dimension (in the direction of the sine waves) -- as a normalized proportion of filter size
	SigWd float32 `` /* 154-byte string literal not displayed */

	// [def: 0,90] [viewif: On] phase offset for the sine wave, in degrees -- 0 = asymmetric sine wave, 90 = symmetric cosine wave
	Phase float32 `` /* 128-byte string literal not displayed */

	// [def: true] [viewif: On] cut off the filter (to zero) outside a circle of diameter = Size -- makes the filter more radially symmetric
	CircleEdge bool `` /* 138-byte string literal not displayed */

	// [def: 4] [viewif: On] number of different angles of overall gabor filter orientation to use -- first angle is always horizontal
	NAngles int `` /* 132-byte string literal not displayed */
}

gabor.Filter specifies a gabor filter function, i.e., a 2d Gaussian envelope times a sinusoidal plane wave. By default it produces 2 phase asymmetric edge detector filters.

func (*Filter) Defaults

func (gf *Filter) Defaults()

func (*Filter) SetSize

func (gf *Filter) SetSize(sz, spc int)

SetSize sets the size and WvLen to same value, and also sets spacing these are the main params that need to be varied for standard V1 gabors

func (*Filter) ToTable

func (gf *Filter) ToTable(tab *etable.Table)

ToTable renders filters into the given etable.Table setting a column named Angle to the angle and a column named Gabor to the filter for that angle. This is useful for display and validation purposes.

func (*Filter) ToTensor

func (gf *Filter) ToTensor(tsr *etensor.Float32)

ToTensor renders filters into the given etable etensor.Tensor, setting dimensions to [angle][Y][X] where Y = X = Size

func (*Filter) Update

func (gf *Filter) Update()