av/turbidity/transform.go

81 lines
2.4 KiB
Go

//go:build !nocv
// +build !nocv
/*
DESCRIPTION
AUTHORS
Russell Stanley <russell@ausocean.org>
LICENSE
Copyright (C) 2021-2022 the Australian Ocean Lab (AusOcean)
It is free software: you can redistribute it and/or modify them
under the terms of the GNU General Public License as published by the
Free Software Foundation, either version 3 of the License, or (at your
option) any later version.
It is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
in gpl.txt. If not, see http://www.gnu.org/licenses.
*/
package turbidity
import (
"errors"
"fmt"
"image"
"gocv.io/x/gocv"
)
// Homography constants
const (
ransacThreshold = 3.0 // Maximum allowed reprojection error to treat a point pair as an inlier.
maxIter = 2000 // The maximum number of RANSAC iterations.
confidence = 0.995 // Confidence level, between 0 and 1.
)
func FindTransform(standardPath, templatePath string) (gocv.Mat, error) {
mask := gocv.NewMat()
standard := gocv.IMRead(standardPath, gocv.IMReadColor)
standardCorners := gocv.NewMat()
template := gocv.IMRead(templatePath, gocv.IMReadGrayScale)
templateCorners := gocv.NewMat()
// Validate template image is not empty and has valid corners.
if template.Empty() {
return gocv.NewMat(), errors.New("template image is empty")
}
if !gocv.FindChessboardCorners(template, image.Pt(3, 3), &templateCorners, gocv.CalibCBNormalizeImage) {
return gocv.NewMat(), errors.New("could not find corners in template image")
}
// Validate standard image is not empty and has valid corners.
if standard.Empty() {
return gocv.NewMat(), errors.New("standard image is empty")
}
if !gocv.FindChessboardCorners(standard, image.Pt(3, 3), &standardCorners, gocv.CalibCBNormalizeImage) {
return gocv.NewMat(), errors.New("could not find corners in standard image")
}
H := gocv.FindHomography(standardCorners, &templateCorners, gocv.HomograpyMethodRANSAC, ransacThreshold, &mask, maxIter, confidence)
fmt.Print(H.Type())
for i := 0; i < H.Rows(); i++ {
for j := 0; j < H.Cols(); j++ {
fmt.Printf(" %.10f", H.GetDoubleAt(i, j))
if i < 2 || j < 2 {
fmt.Print(",")
}
}
}
fmt.Println()
return H, nil
}