transforms

Documentation

Overview

Package transforms provides the transformations for imagehash

Index

• func DCT1D(input []float64) []float64
• func DCT2D(input [][]float64, w int, h int) [][]float64
• func DCT2DHash256(input *[]float64) [256]float64
• func DCT2DHash64(input *[]float64) [64]float64
• func FlattenPixels(pixels [][]float64, x int, y int) []float64
• func LinearTosRGB(value float64) int
• func MeanOfPixels(pixels []float64) float64
• func MedianOfPixels(pixels []float64) float64
• func MedianOfPixels256(pixels []float64) float64
• func MedianOfPixels64(pixels []float64) float64
• func OldYCbCR2Gray(colorImg *image.YCbCr, pixels []float64, s int)
• func PixelYCnCRGray(img *image.YCbCr, pixels []float64)
• func Rgb2Gray(colorImg image.Image) [][]float64
• func Rgb2GrayFast(colorImg image.Image, pixels *[]float64)
• func SRGBToLinear(value int) float64
• func SignPow(value, exp float64) float64
• func YCbCR2Gray(colorImg *image.YCbCr, pixels []float64)

Functions

func DCT1D

func DCT1D(input []float64) []float64

DCT1D function returns result of DCT-II. DCT type II, unscaled. Algorithm by Byeong Gi Lee, 1984.

func DCT2D

func DCT2D(input [][]float64, w int, h int) [][]float64

DCT2D function returns a result of DCT2D by using the seperable property.

func DCT2DHash256

func DCT2DHash256(input *[]float64) [256]float64

DCT2DHash256 function returns a result of DCT2D by using the seperable property. DCT type II, unscaled. Algorithm by Byeong Gi Lee, 1984. Cusstom built for Hash256. Returns flattened pixels

func DCT2DHash64

func DCT2DHash64(input *[]float64) [64]float64

DCT2DHash64 function returns a result of DCT2D by using the seperable property. DCT type II, unscaled. Algorithm by Byeong Gi Lee, 1984. Cusstom built for Hash64. Returns flattened pixels

func FlattenPixels

func FlattenPixels(pixels [][]float64, x int, y int) []float64

FlattenPixels function flattens 2d array into 1d array.

func LinearTosRGB

func LinearTosRGB(value float64) int

func MeanOfPixels

func MeanOfPixels(pixels []float64) float64

MeanOfPixels function returns a mean of pixels.

func MedianOfPixels

func MedianOfPixels(pixels []float64) float64

MedianOfPixels function returns a median value of pixels. It uses quick selection algorithm.

func MedianOfPixels256

func MedianOfPixels256(pixels []float64) float64

MedianOfPixels256 function returns a median value of pixels. It uses quick selection algorithm.

func MedianOfPixels64

func MedianOfPixels64(pixels []float64) float64

MedianOfPixels64 function returns a median value of pixels. It uses quick selection algorithm.

func OldYCbCR2Gray

func OldYCbCR2Gray(colorImg *image.YCbCr, pixels []float64, s int)

OldYCbCR2Gray uses *image.YCbCr which is signifiantly faster than the image.Image interface.

func PixelYCnCRGray

func PixelYCnCRGray(img *image.YCbCr, pixels []float64)

func Rgb2Gray

func Rgb2Gray(colorImg image.Image) [][]float64

Rgb2Gray function converts RGB to a gray scale array.

func Rgb2GrayFast

func Rgb2GrayFast(colorImg image.Image, pixels *[]float64)

Rgb2GrayFast function converts RGB to a gray scale array.

func SRGBToLinear

func SRGBToLinear(value int) float64

func SignPow

func SignPow(value, exp float64) float64

func YCbCR2Gray

func YCbCR2Gray(colorImg *image.YCbCr, pixels []float64)

YCbCR2Gray uses *image.YCbCr which is signifiantly faster than the image.Image interface.