Begin add ResizeMode [skip ci]

Former-commit-id: 7d28a87716e4b7c2dea73bc0fb804873d30372f6
Former-commit-id: 433c2d3c310ed0e361c42601ae4432d97a074fcf
Former-commit-id: abf2e280afbcc9bc0d02cdfe74921f2763ce0f8d

src/ImageProcessorCore/Common/Extensions/ByteExtensions.cs

@@ -33,7 +33,7 @@ namespace ImageProcessorCore
                 result = new byte[bytes.Length * 8 / bits];
 
                 // BUGFIX I dont think it should be there, but I am not sure if it breaks something else
-                //int factor = (int)Math.Pow(2, bits) - 1;
+                // int factor = (int)Math.Pow(2, bits) - 1;
                 int mask = 0xFF >> (8 - bits);
                 int resultOffset = 0;
 
@@ -41,7 +41,7 @@ namespace ImageProcessorCore
                 {
                     for (int shift = 0; shift < 8; shift += bits)
                     {
-                        int colorIndex = ((b >> (8 - bits - shift)) & mask); // * (255 / factor);
+                        int colorIndex = (b >> (8 - bits - shift)) & mask; // * (255 / factor);
 
                         result[resultOffset] = (byte)colorIndex;
 

src/ImageProcessorCore/ParallelImageProcessor.cs

@@ -93,9 +93,13 @@ namespace ImageProcessorCore
                     sourceRectangle = source.Bounds;
                 }
 
-                this.OnApply(source, target, target.Bounds, sourceRectangle);
+                if (targetRectangle == Rectangle.Empty)
+                {
+                    targetRectangle = target.Bounds;
+                }
+
+                this.OnApply(source, target, targetRectangle, sourceRectangle);
 
-                targetRectangle = target.Bounds;
                 this.numRowsProcessed = 0;
                 this.totalRows = targetRectangle.Bottom;
 

src/ImageProcessorCore/Samplers/AnchorPosition.cs

@@ -0,0 +1,58 @@
+// <copyright file="AnchorPosition.cs" company="James Jackson-South">
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+// </copyright>
+
+namespace ImageProcessorCore.Samplers
+{
+    /// <summary>
+    /// Enumerated anchor positions to apply to resized images.
+    /// </summary>
+    public enum AnchorPosition
+    {
+        /// <summary>
+        /// Anchors the position of the image to the center of it's bounding container.
+        /// </summary>
+        Center,
+
+        /// <summary>
+        /// Anchors the position of the image to the top of it's bounding container.
+        /// </summary>
+        Top,
+
+        /// <summary>
+        /// Anchors the position of the image to the bottom of it's bounding container.
+        /// </summary>
+        Bottom,
+
+        /// <summary>
+        /// Anchors the position of the image to the left of it's bounding container.
+        /// </summary>
+        Left,
+
+        /// <summary>
+        /// Anchors the position of the image to the right of it's bounding container.
+        /// </summary>
+        Right,
+
+        /// <summary>
+        /// Anchors the position of the image to the top left side of it's bounding container.
+        /// </summary>
+        TopLeft,
+
+        /// <summary>
+        /// Anchors the position of the image to the top right side of it's bounding container.
+        /// </summary>
+        TopRight,
+
+        /// <summary>
+        /// Anchors the position of the image to the bottom right side of it's bounding container.
+        /// </summary>
+        BottomRight,
+
+        /// <summary>
+        /// Anchors the position of the image to the bottom left side of it's bounding container.
+        /// </summary>
+        BottomLeft
+    }
+}

src/ImageProcessorCore/Samplers/ImageSamplerExtensions.cs

@@ -82,6 +82,32 @@ namespace ImageProcessorCore.Samplers
             }
         }
 
+        /// <summary>
+        /// Resizes an image in accordance with the given <see cref="ResizeOptions"/>.
+        /// </summary>
+        /// <param name="source">The image to resize.</param>
+        /// <param name="options">The resize options.</param>
+        /// <param name="progressHandler">A delegate which is called as progress is made processing the image.</param>
+        /// <returns>The <see cref="Image"/></returns>
+        /// <remarks>Passing zero for one of height or width within the resize options will automatically preserve the aspect ratio of the original image</remarks>
+        public static Image Resize(this Image source, ResizeOptions options, ProgressEventHandler progressHandler = null)
+        {
+            // Ensure size is populated acros both dimensions.
+            if (options.Size.Width == 0 && options.Size.Height > 0)
+            {
+                options.Size = new Size(source.Width * options.Size.Height / source.Height, options.Size.Height);
+            }
+
+            if (options.Size.Height == 0 && options.Size.Width > 0)
+            {
+                options.Size = new Size(options.Size.Width, source.Height * options.Size.Width / source.Width);
+            }
+
+            Rectangle targetRectangle = ResizeHelper.CalculateTargetLocationAndBounds(source, options);
+
+            return Resize(source, options.Size.Width, options.Size.Height, options.Sampler, source.Bounds, targetRectangle, options.Compand, progressHandler);
+        }
+
         /// <summary>
         /// Resizes an image to the given width and height.
         /// </summary>
@@ -124,7 +150,7 @@ namespace ImageProcessorCore.Samplers
         /// <remarks>Passing zero for one of height or width will automatically preserve the aspect ratio of the original image</remarks>
         public static Image Resize(this Image source, int width, int height, IResampler sampler, bool compand, ProgressEventHandler progressHandler = null)
         {
-            return Resize(source, width, height, sampler, source.Bounds, compand, progressHandler);
+            return Resize(source, width, height, sampler, source.Bounds, new Rectangle(0, 0, width, height), compand, progressHandler);
         }
 
         /// <summary>
@@ -138,11 +164,14 @@ namespace ImageProcessorCore.Samplers
         /// <param name="sourceRectangle">
         /// The <see cref="Rectangle"/> structure that specifies the portion of the image object to draw.
         /// </param>
+        /// <param name="targetRectangle">
+        /// The <see cref="Rectangle"/> structure that specifies the portion of the target image object to draw to.
+        /// </param>
         /// <param name="compand">Whether to compress and expand the image color-space to gamma correct the image during processing.</param>
         /// <param name="progressHandler">A delegate which is called as progress is made processing the image.</param>
         /// <returns>The <see cref="Image"/></returns>
         /// <remarks>Passing zero for one of height or width will automatically preserve the aspect ratio of the original image</remarks>
-        public static Image Resize(this Image source, int width, int height, IResampler sampler, Rectangle sourceRectangle, bool compand = false, ProgressEventHandler progressHandler = null)
+        public static Image Resize(this Image source, int width, int height, IResampler sampler, Rectangle sourceRectangle, Rectangle targetRectangle, bool compand = false, ProgressEventHandler progressHandler = null)
         {
             if (width == 0 && height > 0)
             {
@@ -159,7 +188,7 @@ namespace ImageProcessorCore.Samplers
 
             try
             {
-                return source.Process(width, height, sourceRectangle, new Rectangle(0, 0, width, height), processor);
+                return source.Process(width, height, sourceRectangle, targetRectangle, processor);
             }
             finally
             {

src/ImageProcessorCore/Samplers/Resize.cs

@@ -5,6 +5,7 @@
 
 namespace ImageProcessorCore.Samplers
 {
+    using System;
     using System.Threading.Tasks;
 
     /// <summary>
@@ -47,12 +48,14 @@ namespace ImageProcessorCore.Samplers
         protected override void Apply(ImageBase target, ImageBase source, Rectangle targetRectangle, Rectangle sourceRectangle, int startY, int endY)
         {
             // Jump out, we'll deal with that later.
-            if (source.Bounds == target.Bounds)
+            // TODO: Add rectangle comparison.
+            if (source.Bounds == target.Bounds && sourceRectangle == targetRectangle)
             {
                 return;
             }
 
-            int sourceBottom = source.Bounds.Bottom;
+            int width = target.Width;
+            int height = target.Height;
             int targetY = targetRectangle.Y;
             int targetBottom = targetRectangle.Bottom;
             int startX = targetRectangle.X;
@@ -82,6 +85,7 @@ namespace ImageProcessorCore.Samplers
 
                                 target[x, y] = source[originX, originY];
                             }
+
                             this.OnRowProcessed();
                         }
                     });
@@ -92,16 +96,20 @@ namespace ImageProcessorCore.Samplers
 
             // Interpolate the image using the calculated weights.
             // A 2-pass 1D algorithm appears to be faster than splitting a 1-pass 2D algorithm 
-            // First process the columns.
+            // First process the columns. Since we are not using multiple threads startY and endY
+            // are the upper and lower bounds of the source rectangle.
             Parallel.For(
-                0,
-                sourceBottom,
+                startY,
+                endY,
                 y =>
                 {
                     for (int x = startX; x < endX; x++)
                     {
-                        float sum = this.HorizontalWeights[x].Sum;
-                        Weight[] horizontalValues = this.HorizontalWeights[x].Values;
+                        // Ensure offsets are normalised for cropping and padding.
+                        int offsetX = x - startX;
+
+                        float sum = this.HorizontalWeights[offsetX].Sum;
+                        Weight[] horizontalValues = this.HorizontalWeights[offsetX].Values;
 
                         // Destination color components
                         Color destination = new Color();
@@ -119,7 +127,10 @@ namespace ImageProcessorCore.Samplers
                             destination = Color.Compress(destination);
                         }
 
-                        this.firstPass[x, y] = destination;
+                        if (x >= 0 && x < width)
+                        {
+                            this.firstPass[x, y] = destination;
+                        }
                     }
                 });
 
@@ -129,34 +140,37 @@ namespace ImageProcessorCore.Samplers
                 endY,
                 y =>
                 {
-                    if (y >= targetY && y < targetBottom)
+                    // Ensure offsets are normalised for cropping and padding.
+                    int offsetY = y - startY;
+
+                    float sum = this.VerticalWeights[offsetY].Sum;
+                    Weight[] verticalValues = this.VerticalWeights[offsetY].Values;
+
+                    for (int x = 0; x < width; x++)
                     {
-                        float sum = this.VerticalWeights[y].Sum;
-                        Weight[] verticalValues = this.VerticalWeights[y].Values;
+                        // Destination color components
+                        Color destination = new Color();
 
-                        for (int x = startX; x < endX; x++)
+                        for (int i = 0; i < sum; i++)
                         {
-                            // Destination color components
-                            Color destination = new Color();
-
-                            for (int i = 0; i < sum; i++)
-                            {
-                                Weight yw = verticalValues[i];
-                                int originY = yw.Index;
-                                Color sourceColor = compand ? Color.Expand(this.firstPass[x, originY]) : this.firstPass[x, originY];
-                                destination += sourceColor * yw.Value;
-                            }
+                            Weight yw = verticalValues[i];
+                            int originY = yw.Index;
+                            Color sourceColor = compand ? Color.Expand(this.firstPass[x, originY]) : this.firstPass[x, originY];
+                            destination += sourceColor * yw.Value;
+                        }
 
-                            if (compand)
-                            {
-                                destination = Color.Compress(destination);
-                            }
+                        if (compand)
+                        {
+                            destination = Color.Compress(destination);
+                        }
 
+                        if (y >= 0 && y < height)
+                        {
                             target[x, y] = destination;
                         }
-
-                        this.OnRowProcessed();
                     }
+
+                    this.OnRowProcessed();
                 });
         }
 
@@ -164,7 +178,7 @@ namespace ImageProcessorCore.Samplers
         protected override void AfterApply(ImageBase source, ImageBase target, Rectangle targetRectangle, Rectangle sourceRectangle)
         {
             // Copy the pixels over.
-            if (source.Bounds == target.Bounds)
+            if (source.Bounds == target.Bounds && sourceRectangle == targetRectangle)
             {
                 target.ClonePixels(target.Width, target.Height, source.Pixels);
             }

src/ImageProcessorCore/Samplers/ResizeHelper.cs

@@ -0,0 +1,235 @@
+// <copyright file="ResizeHelper.cs" company="James Jackson-South">
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+// </copyright>
+
+namespace ImageProcessorCore.Samplers
+{
+    using System;
+    using System.Linq;
+
+    /// <summary>
+    /// Provides methods to help calculate the target rectangle when resizing using the 
+    /// <see cref="ResizeMode"/> enumeration.
+    /// </summary>
+    internal static class ResizeHelper
+    {
+        /// <summary>
+        /// Calculates the target location and bounds to perform the resize operation against.
+        /// </summary>
+        /// <param name="source">The source image.</param>
+        /// <param name="options">The resize options.</param>
+        /// <returns>
+        /// The <see cref="Rectangle"/>.
+        /// </returns>
+        public static Rectangle CalculateTargetLocationAndBounds(ImageBase source, ResizeOptions options)
+        {
+            switch (options.Mode)
+            {
+                case ResizeMode.Pad:
+                    return CalculatePadRectangle(source, options);
+
+                // TODO: Additional modes
+                // Default case ResizeMode.Crop
+                default:
+                    return CalculateCropRectangle(source, options);
+            }
+        }
+
+        /// <summary>
+        /// Calculates the target rectangle for crop mode.
+        /// </summary>
+        /// <param name="source">The source image.</param>
+        /// <param name="options">The resize options.</param>
+        /// <returns>
+        /// The <see cref="Rectangle"/>.
+        /// </returns>
+        private static Rectangle CalculateCropRectangle(ImageBase source, ResizeOptions options)
+        {
+            int width = options.Size.Width;
+            int height = options.Size.Height;
+
+            if (width <= 0 || height <= 0)
+            {
+                return new Rectangle(0, 0, source.Width, source.Height);
+            }
+
+            double ratio;
+            int sourceWidth = source.Width;
+            int sourceHeight = source.Height;
+
+            int destinationX = 0;
+            int destinationY = 0;
+            int destinationWidth = width;
+            int destinationHeight = height;
+
+            // Fractional variants for preserving aspect ratio.
+            double percentHeight = Math.Abs(height / (double)sourceHeight);
+            double percentWidth = Math.Abs(width / (double)sourceWidth);
+
+            if (percentHeight < percentWidth)
+            {
+                ratio = percentWidth;
+
+                if (options.CenterCoordinates.Any())
+                {
+                    double center = -(ratio * sourceHeight) * options.CenterCoordinates.First();
+                    destinationY = (int)center + (height / 2);
+
+                    if (destinationY > 0)
+                    {
+                        destinationY = 0;
+                    }
+
+                    if (destinationY < (int)(height - (sourceHeight * ratio)))
+                    {
+                        destinationY = (int)(height - (sourceHeight * ratio));
+                    }
+                }
+                else
+                {
+                    switch (options.Position)
+                    {
+                        case AnchorPosition.Top:
+                        case AnchorPosition.TopLeft:
+                        case AnchorPosition.TopRight:
+                            destinationY = 0;
+                            break;
+                        case AnchorPosition.Bottom:
+                        case AnchorPosition.BottomLeft:
+                        case AnchorPosition.BottomRight:
+                            destinationY = (int)(height - (sourceHeight * ratio));
+                            break;
+                        default:
+                            destinationY = (int)((height - (sourceHeight * ratio)) / 2);
+                            break;
+                    }
+                }
+
+                destinationHeight = (int)Math.Ceiling(sourceHeight * percentWidth);
+            }
+            else
+            {
+                ratio = percentHeight;
+
+                if (options.CenterCoordinates.Any())
+                {
+                    double center = -(ratio * sourceWidth) * options.CenterCoordinates.ToArray()[1];
+                    destinationX = (int)center + (width / 2);
+
+                    if (destinationX > 0)
+                    {
+                        destinationX = 0;
+                    }
+
+                    if (destinationX < (int)(width - (sourceWidth * ratio)))
+                    {
+                        destinationX = (int)(width - (sourceWidth * ratio));
+                    }
+                }
+                else
+                {
+                    switch (options.Position)
+                    {
+                        case AnchorPosition.Left:
+                        case AnchorPosition.TopLeft:
+                        case AnchorPosition.BottomLeft:
+                            destinationX = 0;
+                            break;
+                        case AnchorPosition.Right:
+                        case AnchorPosition.TopRight:
+                        case AnchorPosition.BottomRight:
+                            destinationX = (int)(width - (sourceWidth * ratio));
+                            break;
+                        default:
+                            destinationX = (int)((width - (sourceWidth * ratio)) / 2);
+                            break;
+                    }
+                }
+
+                destinationWidth = (int)Math.Ceiling(sourceWidth * percentHeight);
+            }
+
+            return new Rectangle(destinationX, destinationY, destinationWidth, destinationHeight);
+        }
+
+        /// <summary>
+        /// Calculates the target rectangle for pad mode.
+        /// </summary>
+        /// <param name="source">The source image.</param>
+        /// <param name="options">The resize options.</param>
+        /// <returns>
+        /// The <see cref="Rectangle"/>.
+        /// </returns>
+        private static Rectangle CalculatePadRectangle(ImageBase source, ResizeOptions options)
+        {
+            int width = options.Size.Width;
+            int height = options.Size.Height;
+
+            if (width <= 0 || height <= 0)
+            {
+                return new Rectangle(0, 0, source.Width, source.Height);
+            }
+
+            double ratio;
+            int sourceWidth = source.Width;
+            int sourceHeight = source.Height;
+
+            int destinationX = 0;
+            int destinationY = 0;
+            int destinationWidth = width;
+            int destinationHeight = height;
+
+            // Fractional variants for preserving aspect ratio.
+            double percentHeight = Math.Abs(height / (double)sourceHeight);
+            double percentWidth = Math.Abs(width / (double)sourceWidth);
+
+            if (percentHeight < percentWidth)
+            {
+                ratio = percentHeight;
+                destinationWidth = Convert.ToInt32(sourceWidth * percentHeight);
+
+                switch (options.Position)
+                {
+                    case AnchorPosition.Left:
+                    case AnchorPosition.TopLeft:
+                    case AnchorPosition.BottomLeft:
+                        destinationX = 0;
+                        break;
+                    case AnchorPosition.Right:
+                    case AnchorPosition.TopRight:
+                    case AnchorPosition.BottomRight:
+                        destinationX = (int)(width - (sourceWidth * ratio));
+                        break;
+                    default:
+                        destinationX = Convert.ToInt32((width - (sourceWidth * ratio)) / 2);
+                        break;
+                }
+            }
+            else
+            {
+                ratio = percentWidth;
+                destinationHeight = Convert.ToInt32(sourceHeight * percentWidth);
+
+                switch (options.Position)
+                {
+                    case AnchorPosition.Top:
+                    case AnchorPosition.TopLeft:
+                    case AnchorPosition.TopRight:
+                        destinationY = 0;
+                        break;
+                    case AnchorPosition.Bottom:
+                    case AnchorPosition.BottomLeft:
+                    case AnchorPosition.BottomRight:
+                        destinationY = (int)(height - (sourceHeight * ratio));
+                        break;
+                    default:
+                        destinationY = (int)((height - (sourceHeight * ratio)) / 2);
+                        break;
+                }
+            }
+
+            return new Rectangle(destinationX, destinationY, destinationWidth, destinationHeight);
+        }
+    }
+}

src/ImageProcessorCore/Samplers/ResizeMode.cs

@@ -0,0 +1,47 @@
+// <copyright file="ResizeMode.cs" company="James Jackson-South">
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+// </copyright>
+
+namespace ImageProcessorCore.Samplers
+{
+    /// <summary>
+    /// Enumerated resize modes to apply to resized images.
+    /// </summary>
+    public enum ResizeMode
+    {
+        /// <summary>
+        /// Crops the resized image to fit the bounds of its container.
+        /// </summary>
+        Crop,
+
+        /// <summary>
+        /// Pads the resized image to fit the bounds of its container.
+        /// If only one dimension is passed, will maintain the original aspect ratio.
+        /// </summary>
+        Pad,
+
+        /// <summary>
+        /// Stretches the resized image to fit the bounds of its container.
+        /// </summary>
+        Stretch,
+
+        /// <summary>
+        /// Constrains the resized image to fit the bounds of its container maintaining
+        /// the original aspect ratio. 
+        /// </summary>
+        Max,
+
+        /// <summary>
+        /// Resizes the image until the shortest side reaches the set given dimension.
+        /// </summary>
+        Min,
+
+        /// <summary>
+        /// Pads the image to fit the bound of the container without resizing the 
+        /// original source.
+        /// When downscaling, performs the same functionality as <see cref="ResizeMode.Pad"/>
+        /// </summary>
+        BoxPad
+    }
+}

src/ImageProcessorCore/Samplers/ResizeOptions.cs

@@ -0,0 +1,40 @@
+// <copyright file="ResizeOptions.cs" company="James Jackson-South">
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+// </copyright>
+
+namespace ImageProcessorCore.Samplers
+{
+    using System.Collections.Generic;
+    using System.Linq;
+
+    /// <summary>
+    /// The resize options for resizing images against certain modes.
+    /// </summary>
+    public class ResizeOptions
+    {
+        /// <summary>
+        /// Gets or sets the resize mode.
+        /// </summary>
+        public ResizeMode Mode { get; set; } = ResizeMode.Crop;
+
+        /// <summary>
+        /// Gets or sets the anchor position.
+        /// </summary>
+        public AnchorPosition Position { get; set; } = AnchorPosition.Center;
+
+        /// <summary>
+        /// Gets or sets the center coordinates.
+        /// </summary>
+        public IEnumerable<float> CenterCoordinates { get; set; } = Enumerable.Empty<float>();
+
+        /// <summary>
+        /// Gets or sets the target size.
+        /// </summary>
+        public Size Size { get; set; }
+
+        public IResampler Sampler { get; set; } = new BicubicResampler();
+
+        public bool Compand { get; set; }
+    }
+}

tests/ImageProcessorCore.Tests/Processors/Samplers/SamplerTests.cs

@@ -141,7 +141,7 @@
                 Directory.CreateDirectory("TestOutput/Resize");
             }
 
-            var name = "FixedHeight";
+            string name = "FixedHeight";
 
             foreach (string file in Files)
             {
@@ -162,6 +162,73 @@
             }
         }
 
+        [Fact]
+        public void ImageShouldResizeWithCropMode()
+        {
+            if (!Directory.Exists("TestOutput/ResizeCrop"))
+            {
+                Directory.CreateDirectory("TestOutput/ResizeCrop");
+            }
+
+            foreach (string file in Files)
+            {
+                using (FileStream stream = File.OpenRead(file))
+                {
+                    Stopwatch watch = Stopwatch.StartNew();
+                    string filename = Path.GetFileName(file);
+
+                    using (Image image = new Image(stream))
+                    using (FileStream output = File.OpenWrite($"TestOutput/ResizeCrop/{filename}"))
+                    {
+                        ResizeOptions options = new ResizeOptions()
+                        {
+                            Size = new Size(image.Width / 2, image.Height)
+                        };
+
+                        image.Resize(options, this.ProgressUpdate)
+                             .Save(output);
+                    }
+
+                    Trace.WriteLine($"{filename}: {watch.ElapsedMilliseconds}ms");
+                }
+            }
+
+        }
+
+        [Fact]
+        public void ImageShouldResizeWithPadMode()
+        {
+            if (!Directory.Exists("TestOutput/ResizePad"))
+            {
+                Directory.CreateDirectory("TestOutput/ResizePad");
+            }
+
+            foreach (string file in Files)
+            {
+                using (FileStream stream = File.OpenRead(file))
+                {
+                    Stopwatch watch = Stopwatch.StartNew();
+                    string filename = Path.GetFileName(file);
+
+                    using (Image image = new Image(stream))
+                    using (FileStream output = File.OpenWrite($"TestOutput/ResizePad/{filename}"))
+                    {
+                        ResizeOptions options = new ResizeOptions()
+                        {
+                            Size = new Size(image.Width + 200, image.Height),
+                            Mode = ResizeMode.Pad
+                        };
+
+                        image.Resize(options, this.ProgressUpdate)
+                             .Save(output);
+                    }
+
+                    Trace.WriteLine($"{filename}: {watch.ElapsedMilliseconds}ms");
+                }
+            }
+
+        }
+
         [Theory]
         [MemberData("RotateFlips")]
         public void ImageShouldRotateFlip(RotateType rotateType, FlipType flipType)
@@ -281,7 +348,7 @@
             {
                 using (FileStream stream = File.OpenRead(file))
                 {
-                    
+
                     string filename = Path.GetFileNameWithoutExtension(file) + "-Crop" + Path.GetExtension(file);
 
                     using (Image image = new Image(stream))