Merge pull request #30 from observerly/feature/monochrome/ApplyNoiseReduction

feat: Added (m *MonochromeExposure) ApplyNoiseReduction() to the IRIS monochrome module.

Author: michealroberts

coverage.txt

@@ -1,51 +1,33 @@
 mode: atomic
-github.com/observerly/iris/pkg/iris/convolution.go:5.122,16.40 5 128
-github.com/observerly/iris/pkg/iris/convolution.go:21.2,21.21 1 128
-github.com/observerly/iris/pkg/iris/convolution.go:25.2,25.21 1 128
-github.com/observerly/iris/pkg/iris/convolution.go:29.2,34.12 5 128
-github.com/observerly/iris/pkg/iris/convolution.go:16.40,19.3 2 98
-github.com/observerly/iris/pkg/iris/convolution.go:21.21,23.3 1 112
-github.com/observerly/iris/pkg/iris/convolution.go:25.21,27.3 1 112
-github.com/observerly/iris/pkg/iris/convolution.go:37.126,54.19 8 128
-github.com/observerly/iris/pkg/iris/convolution.go:58.2,58.19 1 128
-github.com/observerly/iris/pkg/iris/convolution.go:62.2,66.21 3 128
-github.com/observerly/iris/pkg/iris/convolution.go:70.2,70.21 1 128
-github.com/observerly/iris/pkg/iris/convolution.go:74.2,79.14 5 128
-github.com/observerly/iris/pkg/iris/convolution.go:54.19,56.3 1 112
-github.com/observerly/iris/pkg/iris/convolution.go:58.19,60.3 1 112
-github.com/observerly/iris/pkg/iris/convolution.go:66.21,68.3 1 112
-github.com/observerly/iris/pkg/iris/convolution.go:70.21,72.3 1 112
-github.com/observerly/iris/pkg/iris/convolution.go:82.124,93.19 5 128
-github.com/observerly/iris/pkg/iris/convolution.go:97.2,97.19 1 128
-github.com/observerly/iris/pkg/iris/convolution.go:101.2,101.36 1 128
-github.com/observerly/iris/pkg/iris/convolution.go:106.2,111.13 5 128
-github.com/observerly/iris/pkg/iris/convolution.go:93.19,95.3 1 112
-github.com/observerly/iris/pkg/iris/convolution.go:97.19,99.3 1 112
-github.com/observerly/iris/pkg/iris/convolution.go:101.36,104.3 2 98
-github.com/observerly/iris/pkg/iris/monochrome.go:24.84,37.2 3 7
-github.com/observerly/iris/pkg/iris/monochrome.go:39.79,44.16 3 5
-github.com/observerly/iris/pkg/iris/monochrome.go:48.2,48.18 1 5
-github.com/observerly/iris/pkg/iris/monochrome.go:44.16,46.3 1 0
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-github.com/observerly/iris/pkg/iris/monochrome.go:63.32,66.28 2 215
-github.com/observerly/iris/pkg/iris/monochrome.go:70.3,72.28 2 209
-github.com/observerly/iris/pkg/iris/monochrome.go:76.3,83.29 5 208
-github.com/observerly/iris/pkg/iris/monochrome.go:66.28,67.12 1 6
-github.com/observerly/iris/pkg/iris/monochrome.go:72.28,73.9 1 1
-github.com/observerly/iris/pkg/iris/monochrome.go:83.29,86.4 2 16
-github.com/observerly/iris/pkg/iris/monochrome.go:92.65,99.51 4 4
-github.com/observerly/iris/pkg/iris/monochrome.go:103.2,103.47 1 4
-github.com/observerly/iris/pkg/iris/monochrome.go:107.2,109.29 2 4
-github.com/observerly/iris/pkg/iris/monochrome.go:99.51,101.3 1 784
-github.com/observerly/iris/pkg/iris/monochrome.go:103.47,105.3 1 784
-github.com/observerly/iris/pkg/iris/monochrome.go:112.73,122.51 5 1
-github.com/observerly/iris/pkg/iris/monochrome.go:132.2,132.47 1 1
-github.com/observerly/iris/pkg/iris/monochrome.go:136.2,138.28 2 1
-github.com/observerly/iris/pkg/iris/monochrome.go:122.51,125.26 2 256
-github.com/observerly/iris/pkg/iris/monochrome.go:125.26,127.4 1 251
-github.com/observerly/iris/pkg/iris/monochrome.go:127.9,129.4 1 5
-github.com/observerly/iris/pkg/iris/monochrome.go:132.47,134.3 1 256
+github.com/observerly/iris/pkg/photometry/noise.go:12.77,17.29 2 2
+github.com/observerly/iris/pkg/photometry/noise.go:21.2,26.3 1 2
+github.com/observerly/iris/pkg/photometry/noise.go:17.29,19.3 1 32
+github.com/observerly/iris/pkg/photometry/noise.go:34.53,56.33 6 1
+github.com/observerly/iris/pkg/photometry/noise.go:81.2,83.19 2 1
+github.com/observerly/iris/pkg/photometry/noise.go:56.33,58.34 2 15
+github.com/observerly/iris/pkg/photometry/noise.go:77.3,77.15 1 15
+github.com/observerly/iris/pkg/photometry/noise.go:58.34,66.29 3 225
+github.com/observerly/iris/pkg/photometry/noise.go:73.4,73.25 1 225
+github.com/observerly/iris/pkg/photometry/noise.go:66.29,67.44 1 2025
+github.com/observerly/iris/pkg/photometry/noise.go:67.44,69.6 1 1978
+github.com/observerly/iris/pkg/photometry/stars.go:22.93,27.29 2 2
+github.com/observerly/iris/pkg/photometry/stars.go:31.2,40.3 2 2
+github.com/observerly/iris/pkg/photometry/stars.go:27.29,29.3 1 32
+github.com/observerly/iris/pkg/photometry/stars.go:43.51,46.34 2 1
+github.com/observerly/iris/pkg/photometry/stars.go:66.2,66.14 1 1
+github.com/observerly/iris/pkg/photometry/stars.go:46.34,48.35 1 256
+github.com/observerly/iris/pkg/photometry/stars.go:48.35,52.22 2 24
+github.com/observerly/iris/pkg/photometry/stars.go:62.4,62.29 1 24
+github.com/observerly/iris/pkg/photometry/stars.go:52.22,56.85 2 23
+github.com/observerly/iris/pkg/photometry/stars.go:56.85,58.6 1 5
+github.com/observerly/iris/pkg/fits/fits.go:17.33,28.2 1 2
+github.com/observerly/iris/pkg/fits/fits.go:47.32,52.2 1 1
+github.com/observerly/iris/pkg/fits/fits.go:56.72,59.31 2 1
+github.com/observerly/iris/pkg/fits/fits.go:63.2,63.17 1 1
+github.com/observerly/iris/pkg/fits/fits.go:67.2,78.3 1 1
+github.com/observerly/iris/pkg/fits/fits.go:59.31,61.3 1 2
+github.com/observerly/iris/pkg/fits/fits.go:63.17,65.3 1 1
+github.com/observerly/iris/pkg/fits/fits.go:83.55,98.2 2 1
 github.com/observerly/iris/pkg/iris/rggb.go:22.85,34.2 2 10
 github.com/observerly/iris/pkg/iris/rggb.go:39.85,40.46 1 7
 github.com/observerly/iris/pkg/iris/rggb.go:41.14,42.19 1 3
@@ -69,35 +51,60 @@ github.com/observerly/iris/pkg/iris/rggb.go:132.2,132.22 1 1
 github.com/observerly/iris/pkg/iris/rggb.go:115.16,117.3 1 0
 github.com/observerly/iris/pkg/iris/rggb.go:121.16,123.3 1 0
 github.com/observerly/iris/pkg/iris/rggb.go:128.16,130.3 1 0
-github.com/observerly/iris/pkg/fits/fits.go:17.33,28.2 1 2
-github.com/observerly/iris/pkg/fits/fits.go:47.32,52.2 1 1
-github.com/observerly/iris/pkg/fits/fits.go:56.72,59.31 2 1
-github.com/observerly/iris/pkg/fits/fits.go:63.2,63.17 1 1
-github.com/observerly/iris/pkg/fits/fits.go:67.2,78.3 1 1
-github.com/observerly/iris/pkg/fits/fits.go:59.31,61.3 1 2
-github.com/observerly/iris/pkg/fits/fits.go:63.17,65.3 1 1
-github.com/observerly/iris/pkg/fits/fits.go:83.55,98.2 2 1
+github.com/observerly/iris/pkg/iris/convolution.go:5.122,16.40 5 128
+github.com/observerly/iris/pkg/iris/convolution.go:21.2,21.21 1 128
+github.com/observerly/iris/pkg/iris/convolution.go:25.2,25.21 1 128
+github.com/observerly/iris/pkg/iris/convolution.go:29.2,34.12 5 128
+github.com/observerly/iris/pkg/iris/convolution.go:16.40,19.3 2 98
+github.com/observerly/iris/pkg/iris/convolution.go:21.21,23.3 1 112
+github.com/observerly/iris/pkg/iris/convolution.go:25.21,27.3 1 112
+github.com/observerly/iris/pkg/iris/convolution.go:37.126,54.19 8 128
+github.com/observerly/iris/pkg/iris/convolution.go:58.2,58.19 1 128
+github.com/observerly/iris/pkg/iris/convolution.go:62.2,66.21 3 128
+github.com/observerly/iris/pkg/iris/convolution.go:70.2,70.21 1 128
+github.com/observerly/iris/pkg/iris/convolution.go:74.2,79.14 5 128
+github.com/observerly/iris/pkg/iris/convolution.go:54.19,56.3 1 112
+github.com/observerly/iris/pkg/iris/convolution.go:58.19,60.3 1 112
+github.com/observerly/iris/pkg/iris/convolution.go:66.21,68.3 1 112
+github.com/observerly/iris/pkg/iris/convolution.go:70.21,72.3 1 112
+github.com/observerly/iris/pkg/iris/convolution.go:82.124,93.19 5 128
+github.com/observerly/iris/pkg/iris/convolution.go:97.2,97.19 1 128
+github.com/observerly/iris/pkg/iris/convolution.go:101.2,101.36 1 128
+github.com/observerly/iris/pkg/iris/convolution.go:106.2,111.13 5 128
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+github.com/observerly/iris/pkg/iris/convolution.go:97.19,99.3 1 112
+github.com/observerly/iris/pkg/iris/convolution.go:101.36,104.3 2 98
+github.com/observerly/iris/pkg/iris/monochrome.go:26.84,39.2 3 8
+github.com/observerly/iris/pkg/iris/monochrome.go:41.79,46.16 3 7
+github.com/observerly/iris/pkg/iris/monochrome.go:50.2,50.18 1 7
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 github.com/observerly/iris/pkg/histogram/histogram.go:30.2,30.12 1 0
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-github.com/observerly/iris/pkg/photometry/noise.go:66.29,67.44 1 2025
-github.com/observerly/iris/pkg/photometry/noise.go:67.44,69.6 1 1978
-github.com/observerly/iris/pkg/photometry/stars.go:22.93,27.29 2 2
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-github.com/observerly/iris/pkg/photometry/stars.go:27.29,29.3 1 32
-github.com/observerly/iris/pkg/photometry/stars.go:43.51,46.34 2 1
-github.com/observerly/iris/pkg/photometry/stars.go:66.2,66.14 1 1
-github.com/observerly/iris/pkg/photometry/stars.go:46.34,48.35 1 256
-github.com/observerly/iris/pkg/photometry/stars.go:48.35,52.22 2 24
-github.com/observerly/iris/pkg/photometry/stars.go:62.4,62.29 1 24
-github.com/observerly/iris/pkg/photometry/stars.go:52.22,56.85 2 23
-github.com/observerly/iris/pkg/photometry/stars.go:56.85,58.6 1 5

pkg/iris/monochrome.go

@@ -7,6 +7,7 @@ import (
 	"image/jpeg"
 
 	"github.com/observerly/iris/pkg/histogram"
+	"github.com/observerly/iris/pkg/photometry"
 	"github.com/observerly/iris/pkg/utils"
 )
 
@@ -17,6 +18,7 @@ type MonochromeExposure struct {
 	Buffer    bytes.Buffer
 	Image     *image.Gray
 	Otsu      *image.Gray
+	Noise     float64
 	Threshold uint8
 	Pixels    int
 }
@@ -109,6 +111,36 @@ func (m *MonochromeExposure) Preprocess() (bytes.Buffer, error) {
 	return m.GetBuffer(m.Image)
 }
 
+func (m *MonochromeExposure) ApplyNoiseReduction() (bytes.Buffer, error) {
+	bounds := m.Image.Bounds()
+
+	size := bounds.Size()
+
+	gray := image.NewGray(bounds)
+
+	noise := photometry.NewNoiseExtractor(m.Raw, m.Width, m.Height)
+
+	m.Noise = noise.GetGaussianNoise()
+
+	setPixel := func(gray *image.Gray, x int, y int) {
+		pixel := m.Raw[x][y]
+
+		if pixel < uint32(m.Noise) {
+			gray.SetGray(x, y, color.Gray{Y: 0})
+		} else {
+			gray.SetGray(x, y, color.Gray{uint8(pixel - uint32(m.Noise))})
+		}
+	}
+
+	utils.DeferForEachPixel(size, func(x, y int) {
+		setPixel(gray, x, y)
+	})
+
+	m.Image = gray
+
+	return m.GetBuffer(m.Image)
+}
+
 func (m *MonochromeExposure) ApplyOtsuThreshold() (bytes.Buffer, error) {
 	bounds := m.Image.Bounds()
 

pkg/iris/monochrome_test.go

@@ -236,6 +236,82 @@ func TestNewMonochromeExposureOtsuThreshold(t *testing.T) {
 	}
 }
 
+func TestNewMonochromeExposureNoiseReduction16x16(t *testing.T) {
+	var ex = [][]uint32{
+		{6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6},
+		{6, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 7, 6},
+		{7, 8, 9, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 9, 8, 7},
+		{6, 7, 8, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 8, 7, 6},
+		{6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6},
+		{6, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 7, 6},
+		{7, 8, 9, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 9, 8, 7},
+		{6, 7, 8, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 8, 7, 6},
+		{6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6},
+		{6, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 7, 6},
+		{7, 8, 9, 7, 7, 7, 7, 7, 200, 200, 7, 7, 7, 9, 8, 7},
+		{6, 7, 8, 6, 6, 6, 6, 6, 200, 200, 6, 6, 6, 8, 7, 6},
+		{6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6},
+		{6, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 7, 6},
+		{7, 8, 9, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 9, 8, 7},
+		{6, 7, 8, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 8, 7, 6},
+	}
+
+	mono := NewMonochromeExposure(ex, 16, 16)
+
+	var x int = mono.Width
+
+	var y int = mono.Height
+
+	if x != 16 {
+		t.Errorf("got %q, wanted %q", x, 16)
+	}
+
+	if y != 16 {
+		t.Errorf("got %q, wanted %q", y, 16)
+	}
+
+	mono.Preprocess()
+
+	buff, err := mono.ApplyNoiseReduction()
+
+	if err != nil {
+		t.Errorf("Expected the buffer to be created successfully, but got %q", err)
+	}
+
+	f, err := os.Create("16x16image.jpg")
+
+	if err != nil {
+		panic(err)
+	}
+
+	defer func() {
+		if err := f.Close(); err != nil {
+			t.Errorf("Expected the image buffer to be saved successfully, but got %q", err)
+		}
+
+		// Clean up the file after we have finished with the test:
+		os.Remove("16x16image.jpg")
+	}()
+
+	n, err := f.Write(buff.Bytes())
+
+	if err != nil {
+		t.Errorf("Expected the image buffer to be saved successfully, but got %q", err)
+	}
+
+	if n >= 1086 {
+		t.Errorf("Expected the number of bytes to be approximately less than 1086, but got %q", n)
+	}
+
+	if mono.Noise <= 0.0 {
+		t.Errorf("Noise is %f, expected > 0.0", mono.Noise)
+	}
+
+	if mono.Noise > 255 {
+		t.Errorf("Noise is %f, expected <= 255", mono.Noise)
+	}
+}
+
 func TestNewMonochromeExposureHistogramGray(t *testing.T) {
 	var ex = [][]uint32{
 		{1, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6},