mirror of
https://github.com/Dadido3/noita-mapcap.git
synced 2024-10-16 08:17:32 +00:00
54 lines
1.3 KiB
Go
54 lines
1.3 KiB
Go
|
// Copyright (c) 2019 David Vogel
|
||
|
|
//
|
||
|
|
// This software is released under the MIT License.
|
||
|
|
// https://opensource.org/licenses/MIT
|
||
|
|
|
||
|
|
package main
|
||
|
|
|
||
|
|
import (
|
||
|
|
"fmt"
|
||
|
|
"image"
|
||
|
|
"math"
|
||
|
|
"os"
|
||
|
|
)
|
||
|
|
|
||
|
|
// Source: https://gist.github.com/sergiotapia/7882944
|
||
|
|
func getImageFileDimension(imagePath string) (int, int, error) {
|
||
|
|
file, err := os.Open(imagePath)
|
||
|
|
if err != nil {
|
||
|
|
return 0, 0, fmt.Errorf("Can't open file %v: %w", imagePath, err)
|
||
|
|
}
|
||
|
|
defer file.Close()
|
||
|
|
|
||
|
|
image, _, err := image.DecodeConfig(file)
|
||
|
|
if err != nil {
|
||
|
|
return 0, 0, fmt.Errorf("Error decoding config of image file %v: %w", imagePath, err)
|
||
|
|
}
|
||
|
|
|
||
|
|
return image.Width, image.Height, nil
|
||
|
|
}
|
||
|
|
|
||
|
|
// getImageDifferenceValue returns the average quadratic difference of the (sub)pixels
|
||
|
|
func getImageDifferenceValue(a, b *image.RGBA) float64 {
|
||
|
|
intersection := a.Bounds().Intersect(b.Bounds())
|
||
|
|
|
||
|
|
if intersection.Empty() {
|
||
|
|
return math.Inf(1)
|
||
|
|
}
|
||
|
|
|
||
|
|
aSub := a.SubImage(intersection).(*image.RGBA)
|
||
|
|
bSub := b.SubImage(intersection).(*image.RGBA)
|
||
|
|
|
||
|
|
value := 0.0
|
||
|
|
|
||
|
|
for iy := 0; iy < intersection.Dy(); iy++ {
|
||
|
|
for ix := 0; ix < intersection.Dx()*4; ix++ {
|
||
|
|
aValue := float64(aSub.Pix[ix+iy*aSub.Stride])
|
||
|
|
bValue := float64(bSub.Pix[ix+iy*bSub.Stride])
|
||
|
|
value += math.Pow(aValue-bValue, 2)
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
return value / float64(intersection.Dx()*intersection.Dy())
|
||
|
|
}
|