Much better Vignette

Former-commit-id: d70717994e390056d03b55f1c3f6b5ececd97bc0
Former-commit-id: 92ab616c4b25d03512c764da0bf54916dc0c4c6d
Former-commit-id: 8696473ce6f0867755004503b936e76953c63859

src/ImageProcessor/Colors/Color.cs

@@ -353,7 +353,8 @@ namespace ImageProcessor
             amount = amount.Clamp(0f, 1f);
 
             // Premultiplied.
-            return (from * (1 - amount)) + to;
+            return from + (to - from) * amount;
+            //return (from * (1 - amount)) + to;
         }
 
         /// <summary>

src/ImageProcessor/Filters/ColorMatrix/Lomograph.cs

@@ -22,5 +22,11 @@ namespace ImageProcessor.Filters
             M42 = .0f,
             M43 = -.08f
         };
+
+        /// <inheritdoc/>
+        protected override void AfterApply(ImageBase source, ImageBase target, Rectangle targetRectangle, Rectangle sourceRectangle)
+        {
+            new Vignette { Color = new Color(0, 10 / 255f, 0) }.Apply(target, target, targetRectangle);
+        }
     }
 }

src/ImageProcessor/Filters/ColorMatrix/Polaroid.cs

@@ -28,5 +28,12 @@ namespace ImageProcessor.Filters
             M42 = -0.05f,
             M43 = -0.05f
         };
+
+        /// <inheritdoc/>
+        protected override void AfterApply(ImageBase source, ImageBase target, Rectangle targetRectangle, Rectangle sourceRectangle)
+        {
+            new Vignette { Color = new Color(102 / 255f, 34 / 255f, 0) }.Apply(target, target, targetRectangle);
+            new Glow { Color = new Color(1, 153 / 255f, 102 / 255f) }.Apply(target, target, targetRectangle);
+        }
     }
 }

src/ImageProcessor/Filters/Glow.cs

@@ -0,0 +1,58 @@
+// <copyright file="Glow.cs" company="James Jackson-South">
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+// </copyright>
+
+namespace ImageProcessor.Filters
+{
+    using System;
+    using System.Numerics;
+    using System.Threading.Tasks;
+
+    /// <summary>
+    /// Creates a glow effect on the image
+    /// </summary>
+    public class Glow : ParallelImageProcessor
+    {
+        /// <summary>
+        /// Gets or sets the vignette color to apply.
+        /// </summary>
+        public Color Color { get; set; } = Color.White;
+
+        /// <summary>
+        /// Gets or sets the the x-radius.
+        /// </summary>
+        public float RadiusX { get; set; }
+
+        /// <summary>
+        /// Gets or sets the the y-radius.
+        /// </summary>
+        public float RadiusY { get; set; }
+
+        /// <inheritdoc/>
+        protected override void Apply(ImageBase target, ImageBase source, Rectangle targetRectangle, Rectangle sourceRectangle, int startY, int endY)
+        {
+            int startX = sourceRectangle.X;
+            int endX = sourceRectangle.Right;
+            Color color = this.Color;
+            Vector2 centre = Rectangle.Center(targetRectangle);
+            float rX = this.RadiusX > 0 ? this.RadiusX : targetRectangle.Width / 2f;
+            float rY = this.RadiusY > 0 ? this.RadiusY : targetRectangle.Height / 2f;
+            float maxDistance = (float)Math.Sqrt(rX * rX + rY * rY);
+
+            Parallel.For(
+                startY,
+                endY,
+                y =>
+                    {
+                        for (int x = startX; x < endX; x++)
+                        {
+                            float distance = Vector2.Distance(centre, new Vector2(x, y));
+                            Color sourceColor = target[x, y];
+                            target[x, y] = Color.Lerp(color, sourceColor, 4f * distance / maxDistance);
+                        }
+                    });
+        }
+    }
+}
+

src/ImageProcessor/Filters/Vignette.cs

@@ -1,18 +1,19 @@
-namespace ImageProcessor.Filters
+// <copyright file="Vignette.cs" company="James Jackson-South">
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+// </copyright>
+
+namespace ImageProcessor.Filters
 {
+    using System;
     using System.Numerics;
     using System.Threading.Tasks;
 
     /// <summary>
-    /// Creates a vignette
+    /// Creates a vignette effect on the image
     /// </summary>
     public class Vignette : ParallelImageProcessor
     {
-        /// <summary>
-        /// Used to hold a copy of the target image.
-        /// </summary>
-        private readonly Image targetCopy = new Image();
-
         /// <summary>
         /// Gets or sets the vignette color to apply.
         /// </summary>
@@ -28,26 +29,16 @@
         /// </summary>
         public float RadiusY { get; set; }
 
-        /// <inheritdoc/>
-        protected override void OnApply(ImageBase source, ImageBase target, Rectangle targetRectangle, Rectangle sourceRectangle)
-        {
-            this.targetCopy.SetPixels(target.Width, target.Height, target.Pixels);
-            target.SetPixels(target.Width, target.Height, new float[target.Pixels.Length]);
-        }
-
         /// <inheritdoc/>
         protected override void Apply(ImageBase target, ImageBase source, Rectangle targetRectangle, Rectangle sourceRectangle, int startY, int endY)
         {
             int startX = sourceRectangle.X;
             int endX = sourceRectangle.Right;
-
+            Color color = this.Color;
             Vector2 centre = Rectangle.Center(targetRectangle);
-            int centerX = (int)centre.X;
-            int centerY = (int)centre.Y;
             float rX = this.RadiusX > 0 ? this.RadiusX : targetRectangle.Width / 2f;
             float rY = this.RadiusY > 0 ? this.RadiusY : targetRectangle.Height / 2f;
-
-            Ellipse ellipse = new Ellipse(new Point(centerX, centerY), rX - 1, rY - 1);
+            float maxDistance = (float)Math.Sqrt(rX * rX + rY * rY);
 
             Parallel.For(
                 startY,
@@ -56,22 +47,12 @@
                     {
                         for (int x = startX; x < endX; x++)
                         {
-                            if (!ellipse.Contains(x, y))
-                            {
-                                target[x, y] = Color.Black;
-                            }
+                            float distance = Vector2.Distance(centre, new Vector2(x, y));
+                            Color sourceColor = target[x, y];
+                            target[x, y] = Color.Lerp(sourceColor, color, .9f * distance / maxDistance);
                         }
                     });
         }
-
-        /// <inheritdoc/>
-        protected override void AfterApply(ImageBase source, ImageBase target, Rectangle targetRectangle, Rectangle sourceRectangle)
-        {
-            new GuassianBlur(30).Apply(target, target, targetRectangle);
-            Image temp = new Image(this.targetCopy);
-            new Blend(target, 40).Apply(this.targetCopy, temp, targetRectangle);
-            target.SetPixels(temp.Width, temp.Height, this.targetCopy.Pixels);
-        }
     }
 }
 

src/ImageProcessor/Numerics/Ellipse.cs

@@ -97,7 +97,7 @@ namespace ImageProcessor
 
         /// <summary>
         /// Determines if the specfied point is contained within the rectangular region defined by
-        /// this <see cref="Rectangle"/>.
+        /// this <see cref="Ellipse"/>.
         /// </summary>
         /// <param name="x">The x-coordinate of the given point.</param>
         /// <param name="y">The y-coordinate of the given point.</param>