Increasing color variety in instance segmentation. (#261)

* Increasing color variety in instance segmentation.

* Fixing duplicated color issues in InstanceIdToColorMapping introduced after expanding range.

* Using other constants in constant for cleanliness

com.unity.perception/CHANGELOG.md

 ### Added
 
 ### Changed
+Increased color variety in instance segmentation images
 
 ### Deprecated
 

com.unity.perception/Runtime/GroundTruth/InstanceIdToColorMapping.cs

 using System;
 using System.Collections.Generic;
+using Unity.Profiling;
 
 namespace UnityEngine.Perception.GroundTruth
 {
         /// </summary>
         public const uint maxId = uint.MaxValue - ((256 * 256 * 256) * 2) + k_HslCount;
 
-        static Dictionary<uint, uint> s_IdToColorCache;
+        static uint[] s_IdToColorCache;
-        const uint k_HslCount = 64;
+        const uint k_HslCount = 1024;
-        const int k_HuesInEachValue = 30;
+        const int k_HuesInEachValue = 64;
+        const uint k_Values = k_HslCount / k_HuesInEachValue;
-        static void InitializeMaps()
+
+        private static ProfilerMarker k_InitializeMapsMarker = new ProfilerMarker(nameof(InitializeMaps));
+        internal static void InitializeMaps()
+            using (k_InitializeMapsMarker.Auto())
+            {
+                s_IdToColorCache = new uint[k_HslCount + 1];
+                s_ColorToIdCache = new Dictionary<uint, uint>();
-            s_IdToColorCache = new Dictionary<uint, uint>();
-            s_ColorToIdCache = new Dictionary<uint, uint>();
+                s_IdToColorCache[0] = k_InvalidPackedColor;
+                s_ColorToIdCache[k_InvalidPackedColor] = 0;
-            s_IdToColorCache[0] = k_InvalidPackedColor;
-            s_IdToColorCache[k_InvalidPackedColor] = 0;
-
-            for (uint i = 1; i <= k_HslCount; i++)
-            {
-                var color = GenerateHSLValueForId(i);
-                s_IdToColorCache[i] = color;
-                s_ColorToIdCache[color] = i;
+                for (uint i = 1; i <= k_HslCount; i++)
+                {
+                    var color = GenerateHSLValueForId(i);
+                    s_IdToColorCache[i] = color;
+                    s_ColorToIdCache.Add(color, i);
+                }
             }
         }
 
 
-            var ratio = count * k_GoldenRatio;
+            // assign hue based on golden ratio
+            var hueId = count % k_HuesInEachValue;
+            var ratio = hueId * k_GoldenRatio;
-            count /= k_HuesInEachValue;
-            ratio = count * k_GoldenRatio;
-            var value = 1 - (ratio - Mathf.Floor(ratio));
+            var valueId = count / k_HuesInEachValue;
+
+            // avoid value 0
+            var value = 1 - (float)valueId / (k_Values + 1);
 
             var color = (Color32)Color.HSVToRGB(hue, 1f, value);
             color.a = 255;

com.unity.perception/Tests/Runtime/GroundTruthTests/InstanceIdToColorMappingTests.cs

     public class InstanceIdToColorMappingTests
     {
         [Test]
+        public void InitializeMaps_DoesNotThrow()
+        {
+            Assert.DoesNotThrow(InstanceIdToColorMapping.InitializeMaps);
+        }
+        [Test]
-            for (var i = 1u; i <= 64u; i++)
+            for (var i = 1u; i <= 1024u; i++)
-                Assert.IsTrue(InstanceIdToColorMapping.TryGetColorFromInstanceId(i, out var color));
-                Assert.IsTrue(InstanceIdToColorMapping.TryGetInstanceIdFromColor(color, out var id));
+                Assert.IsTrue(InstanceIdToColorMapping.TryGetColorFromInstanceId(i, out var color), $"Failed TryGetColorFromInstanceId on id {i}");
+                Assert.IsTrue(InstanceIdToColorMapping.TryGetInstanceIdFromColor(color, out var id), $"Failed TryGetInstanceIdFromColor on id {i}");
                 Assert.AreEqual(i, id);
 
                 color = InstanceIdToColorMapping.GetColorFromInstanceId(i);
         [TestCase(4u,255,0,223,255)]
         [TestCase(5u,0,255,212,255)]
         [TestCase(6u,255,138,0,255)]
-        [TestCase(64u,195,0,75,255)]
-        [TestCase(65u,0,0,1,254)]
-        [TestCase(66u,0,0,2,254)]
-        [TestCase(64u + 256u,0,1,0,254)]
-        [TestCase(65u + 256u,0,1,1,254)]
-        [TestCase(64u + 65536u,1,0,0,254)]
-        [TestCase(16777216u,255,255,192,254)]
-        [TestCase(64u + 16777216u,0,0,0,253)]
-        [TestCase(64u + (16777216u * 2),0,0,0,252)]
+        [TestCase(1024u,30, 0, 11,255)]
+        [TestCase(1025u,0,0,1,254)]
+        [TestCase(1026u,0,0,2,254)]
+        [TestCase(1024u + 256u,0,1,0,254)]
+        [TestCase(1025u + 256u,0,1,1,254)]
+        [TestCase(1024u + 65536u,1,0,0,254)]
+        [TestCase(1024u + 16777216u,0,0,0,253)]
+        [TestCase(1024u + (16777216u * 2),0,0,0,252)]
-            Assert.AreEqual(color.r, r);
-            Assert.AreEqual(color.g, g);
-            Assert.AreEqual(color.b, b);
-            Assert.AreEqual(color.a, a);
+            var expected = new Color32(r, g, b, a);
+            Assert.AreEqual(expected, color);
-            Assert.AreEqual(color.r, r);
-            Assert.AreEqual(color.g, g);
-            Assert.AreEqual(color.b, b);
-            Assert.AreEqual(color.a, a);
+            Assert.AreEqual(expected, color);
 
             id2 = InstanceIdToColorMapping.GetInstanceIdFromColor(color);
             Assert.AreEqual(id, id2);
         public void InstanceIdToColorMappingTests_GetCorrectValuesFor255()
         {
-            var expectedColor = new Color(0, 0, 191, 254);
+            var expectedColor = new Color32(19, 210, 0, 255);
-            Assert.AreEqual(color.r, expectedColor.r);
-            Assert.AreEqual(color.g, expectedColor.g);
-            Assert.AreEqual(color.b, expectedColor.b);
-            Assert.AreEqual(color.a, expectedColor.a);
+            Assert.AreEqual(expectedColor, color);
-            Assert.AreEqual(color.r, expectedColor.r);
-            Assert.AreEqual(color.g, expectedColor.g);
-            Assert.AreEqual(color.b, expectedColor.b);
-            Assert.AreEqual(color.a, expectedColor.a);
+            Assert.AreEqual(expectedColor, color);
             id2 = InstanceIdToColorMapping.GetInstanceIdFromColor(color);
             Assert.AreEqual(255u, id2);
         }