ImageSharp/src/ImageProcessor/Processors/Mask.cs

// --------------------------------------------------------------------------------------------------------------------
// <copyright file="Mask.cs" company="James South">
//   Copyright (c) James South.
//   Licensed under the Apache License, Version 2.0.
// </copyright>
// <summary>
//   Applies a mask to the given image.
// </summary>
// --------------------------------------------------------------------------------------------------------------------

namespace ImageProcessor.Processors
{
    using System;
    using System.Collections.Generic;
    using System.Drawing;

    using ImageProcessor.Common.Exceptions;

    /// <summary>
    /// Applies a mask to the given image.
    /// </summary>
    public class Mask : IGraphicsProcessor
    {
        /// <summary>
        /// Initializes a new instance of the <see cref="Mask"/> class.
        /// </summary>
        public Mask()
        {
            this.Settings = new Dictionary<string, string>();
        }

        /// <summary>
        /// Gets or sets the dynamic parameter.
        /// </summary>
        public dynamic DynamicParameter
        {
            get;
            set;
        }

        /// <summary>
        /// Gets or sets any additional settings required by the processor.
        /// </summary>
        public Dictionary<string, string> Settings
        {
            get;
            set;
        }

        /// <summary>
        /// Processes the image.
        /// </summary>
        /// <param name="factory">
        /// The current instance of the <see cref="T:ImageProcessor.ImageFactory"/> class containing
        /// the image to process.
        /// </param>
        /// <returns>
        /// The processed image from the current instance of the <see cref="T:ImageProcessor.ImageFactory"/> class.
        /// </returns>
        public Image ProcessImage(ImageFactory factory)
        {
            Bitmap newImage = null;
            Image image = factory.Image;
            Size original = image.Size;
            Size smaller = new Size(image.Width / 2, image.Height / 2);
            int x = (original.Width - smaller.Width) / 2;
            int y = (original.Height - smaller.Height) / 2;

            int width = image.Width;
            int height = image.Height;

            try
            {
                newImage = new Bitmap(original.Width, image.Height);

                using (Graphics graphics = Graphics.FromImage(newImage))
                {
                    graphics.DrawImage(image, x, y, smaller.Width, smaller.Height);
                }

                image.Dispose();
                image = newImage;
            }
            catch (Exception ex)
            {
                if (newImage != null)
                {
                    newImage.Dispose();
                }

                throw new ImageProcessingException("Error processing image with " + this.GetType().Name, ex);
            }

            return image;
        }
    }
}