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Added IDistanceStrategy interface and replaced ComputeDistance with ComputeSimilarity
A normalized distance is really a measure of similarity, hence the name. The return value has been inverted, representing %-similar instead of %-different.
1 parent c13b807 commit 2f0b794

14 files changed

+65
-31
lines changed

‎src/Gsemac.Core/Extensions/DistanceStrategyExtensions.cs

+23
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,23 @@
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using System;
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namespace Gsemac.Core.Extensions {
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public static class DistanceStrategyExtensions {
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// Public members
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public static double ComputeSimilarity<T>(this IDistanceStrategy<T> distanceStrategy, T first, T second) {
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if (distanceStrategy is null)
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throw new ArgumentNullException(nameof(distanceStrategy));
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double distance = distanceStrategy.ComputeDistance(first, second, normalizeResult: true);
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double similarity = 1.0 - distance;
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return Math.Max(0.0, Math.Min(similarity, 1.0));
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}
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}
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}

‎src/Gsemac.Core/IDistanceStrategy.cs

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@@ -0,0 +1,9 @@
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namespace Gsemac.Core {
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public interface IDistanceStrategy<T> {
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double ComputeDistance(T first, T second, bool normalizeResult = false);
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}
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}

‎src/Gsemac.Drawing/ColorUtilities.cs

+4-3
Original file line numberDiff line numberDiff line change
@@ -1,17 +1,18 @@
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using System.Drawing;
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using Gsemac.Core.Extensions;
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using System.Drawing;
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namespace Gsemac.Drawing {
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public static class ColorUtilities {
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// Public members
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9-
public static double ComputeDistance(Color first, Color second, IColorDistanceStrategy strategy = null) {
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public static double ComputeSimilarity(Color first, Color second, IColorDistanceStrategy strategy = null) {
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if (strategy is null)
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strategy = new DeltaEColorDistanceStrategy();
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return strategy.ComputeDistance(first, second, normalizeResult: true);
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return strategy.ComputeSimilarity(first, second);
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}
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‎src/Gsemac.Drawing/DeltaEColorDistanceStrategy.cs

+1-1
Original file line numberDiff line numberDiff line change
@@ -7,7 +7,7 @@ namespace Gsemac.Drawing {
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public class DeltaEColorDistanceStrategy :
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IColorDistanceStrategy {
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10-
public double ComputeDistance(Color first, Color second, bool normalizeResult = true) {
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public double ComputeDistance(Color first, Color second, bool normalizeResult = false) {
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// Algorithm from https://www.easyrgb.com/en/math.php
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‎src/Gsemac.Drawing/Extensions/ColorExtensions.cs

+1-1
Original file line numberDiff line numberDiff line change
@@ -46,7 +46,7 @@ public static XyzColor ToXyz(this Color color) {
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public static double DistanceTo(this Color color, Color other) {
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49-
return ColorUtilities.ComputeDistance(color, other);
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return ColorUtilities.ComputeSimilarity(color, other);
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}
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‎src/Gsemac.Drawing/GreyscaleRgbDifferenceColorDistanceStrategy.cs

+1-1
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@@ -6,7 +6,7 @@ namespace Gsemac.Drawing {
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public class GreyscaleRgbDifferenceColorDistanceStrategy :
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IColorDistanceStrategy {
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9-
public double ComputeDistance(Color first, Color second, bool normalizeResult = true) {
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public double ComputeDistance(Color first, Color second, bool normalizeResult = false) {
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int grayscaleFirst = ColorUtilities.ToGreyscale(first).R;
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int grayscaleSecond = ColorUtilities.ToGreyscale(second).R;

‎src/Gsemac.Drawing/IColorDistanceStrategy.cs

+4-5
Original file line numberDiff line numberDiff line change
@@ -1,11 +1,10 @@
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using System.Drawing;
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using Gsemac.Core;
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using System.Drawing;
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namespace Gsemac.Drawing {
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public interface IColorDistanceStrategy {
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double ComputeDistance(Color first, Color second, bool normalizeResult = true);
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public interface IColorDistanceStrategy :
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IDistanceStrategy<Color> {
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}
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}

‎src/Gsemac.Drawing/Imaging/TrimImageFilter.cs

+6-4
Original file line numberDiff line numberDiff line change
@@ -123,15 +123,17 @@ public IImage Apply(IImage image) {
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private readonly IColorDistanceStrategy distanceAlgorithm = new DeltaEColorDistanceStrategy();
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private readonly int tolerance = defaultTolerance;
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126-
private bool CompareColors(Color first, Color second) {
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private bool ColorIsMatch(Color first, Color second) {
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return ColorUtilities.ComputeDistance(first, second, distanceAlgorithm) <= tolerance / 100.0;
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double requiredSimilarity = 1.0 - (tolerance / 100.0);
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return ColorUtilities.ComputeSimilarity(first, second, distanceAlgorithm) >= requiredSimilarity;
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}
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private bool RowIsColor(Bitmap bitmap, int row, Color trimColor) {
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for (int x = 0; x < bitmap.Width; ++x)
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if (!CompareColors(bitmap.GetPixel(x, row), trimColor))
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if (!ColorIsMatch(bitmap.GetPixel(x, row), trimColor))
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return false;
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return true;
@@ -140,7 +142,7 @@ private bool RowIsColor(Bitmap bitmap, int row, Color trimColor) {
140142
private bool ColumnIsColor(Bitmap bitmap, int column, Color trimColor) {
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for (int y = 0; y < bitmap.Height; ++y)
143-
if (!CompareColors(bitmap.GetPixel(column, y), trimColor))
145+
if (!ColorIsMatch(bitmap.GetPixel(column, y), trimColor))
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return false;
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return true;

‎src/Gsemac.Drawing/RgbDifferenceColorDistanceStrategy.cs

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@@ -6,7 +6,7 @@ namespace Gsemac.Drawing {
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public class RgbDifferenceColorDistanceStrategy :
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IColorDistanceStrategy {
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9-
public double ComputeDistance(Color first, Color second, bool normalizeResult = true) {
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public double ComputeDistance(Color first, Color second, bool normalizeResult = false) {
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int rDiff = Math.Abs(first.R - second.R);
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int gDiff = Math.Abs(first.G - second.G);

‎src/Gsemac.Text/Gsemac.Text.csproj

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@@ -18,6 +18,10 @@
1818
<DebugSymbols>false</DebugSymbols>
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</PropertyGroup>
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<ItemGroup>
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<ProjectReference Include="..\Gsemac.Core\Gsemac.Core.csproj" />
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</ItemGroup>
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<ItemGroup>
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<Compile Update="Properties\ExceptionMessages.Designer.cs">
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<DesignTime>True</DesignTime>

‎src/Gsemac.Text/IStringDistanceStrategy.cs

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@@ -1,9 +1,9 @@
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namespace Gsemac.Text {
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using Gsemac.Core;
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3-
public interface IStringDistanceStrategy {
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5-
double ComputeDistance(string first, string second, bool normalizeResult = true);
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namespace Gsemac.Text {
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5+
public interface IStringDistanceStrategy :
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IDistanceStrategy<string> {
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}
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}

‎src/Gsemac.Text/LevenshteinStringDistanceStrategy.cs

+3-3
Original file line numberDiff line numberDiff line change
@@ -7,7 +7,7 @@ public class LevenshteinStringDistanceStrategy :
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// Public members
99

10-
public double ComputeDistance(string first, string second, bool normalizeResult = true) {
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public double ComputeDistance(string first, string second, bool normalizeResult = false) {
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1212
if (first is null)
1313
throw new ArgumentNullException(nameof(first));
@@ -22,7 +22,7 @@ public double ComputeDistance(string first, string second, bool normalizeResult
2222
int maxLength = Math.Max(first.Length, second.Length);
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return normalizeResult ?
25-
1.0 - (distance / (double)maxLength) :
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distance / (double)maxLength :
2626
distance;
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2828
}
@@ -89,4 +89,4 @@ private static int ComputeLevenshteinDistance(string str1, string str2) {
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}
9191

92-
}
92+
}

‎src/Gsemac.Text/StringUtilities.cs

+4-3
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@@ -1,4 +1,5 @@
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using Gsemac.Text.Properties;
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using Gsemac.Core.Extensions;
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using Gsemac.Text.Properties;
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using System;
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using System.Collections.Generic;
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using System.Globalization;
@@ -464,12 +465,12 @@ public static StringComparer GetStringComparer(StringComparison stringComparison
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465466
}
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467-
public static double ComputeDistance(string first, string second, IStringDistanceStrategy strategy = null) {
468+
public static double ComputeSimilarity(string first, string second, IStringDistanceStrategy strategy = null) {
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469470
if (strategy is null)
470471
strategy = new LevenshteinStringDistanceStrategy();
471472

472-
return strategy.ComputeDistance(first, second, normalizeResult: true);
473+
return strategy.ComputeSimilarity(first, second);
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474475
}
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public static string ComputeMD5Hash(string input, Encoding encoding = null) {

‎tests/Gsemac.Drawing.Tests/ColorDistanceStrategyTests.cs

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@@ -1,10 +1,5 @@
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using Microsoft.VisualStudio.TestTools.UnitTesting;
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using System;
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using System.Collections.Generic;
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using System.Drawing;
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using System.Linq;
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using System.Text;
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using System.Threading.Tasks;
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namespace Gsemac.Drawing.Tests {
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