40 lines
984 B
Go
40 lines
984 B
Go
// Copyright 2017 The goimagehash Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package transforms
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import (
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"image"
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)
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// Rgb2Gray function converts RGB to a gray scale array.
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func Rgb2Gray(colorImg image.Image) [][]float64 {
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bounds := colorImg.Bounds()
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w, h := bounds.Max.X-bounds.Min.X, bounds.Max.Y-bounds.Min.Y
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pixels := make([][]float64, h)
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for i := range pixels {
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pixels[i] = make([]float64, w)
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for j := range pixels[i] {
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color := colorImg.At(j, i)
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r, g, b, _ := color.RGBA()
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lum := 0.299*float64(r/257) + 0.587*float64(g/257) + 0.114*float64(b/256)
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pixels[i][j] = lum
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}
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}
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return pixels
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}
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// FlattenPixels function flattens 2d array into 1d array.
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func FlattenPixels(pixels [][]float64, x int, y int) []float64 {
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flattens := make([]float64, x*y)
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for i := 0; i < y; i++ {
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for j := 0; j < x; j++ {
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flattens[y*i+j] = pixels[i][j]
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}
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}
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return flattens
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}
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