haar

Documentation

Overview

Package haar provides a Haar wavelet function for bitmap images.

Index

• Constants
• type Coef
  • func (coef *Coef) Add(offset Coef)
  • func (coef *Coef) Divide(value float64)
  • func (coef *Coef) Subtract(offset Coef)
• type Matrix
  • func Transform(img image.Image) Matrix

Constants

const ColourChannels = 3

ColourChannels is the number of channels for one color. We will be using three colour channels per pixel at all times.

Types

type Coef

type Coef [ColourChannels]float64

Coef is the union of coefficients for all channels of the original image.

func (*Coef) Add

func (coef *Coef) Add(offset Coef)

Add adds another coefficient in place.

func (*Coef) Divide

func (coef *Coef) Divide(value float64)

Divide divides all elements of the coefficient by a value, in place.

func (*Coef) Subtract

func (coef *Coef) Subtract(offset Coef)

Subtract subtracts another coefficient in place.

type Matrix

type Matrix struct {
	// Coefs is the slice of coefficients resulting from a forward 2D Haar
	// transform. The position of a coefficient (x,y) is (y * Width + x).
	Coefs []Coef

	// The number of columns in the matrix.
	Width uint

	// The number of rows in the matrix.
	Height uint
}

Matrix is the result of the Haar transform, a two-dimensional matrix of coefficients.

func Transform

func Transform(img image.Image) Matrix

Transform performs a forward 2D Haar transform on the provided image after converting it to YIQ space.