Does basic edge detection on an image - CSharp System.Drawing

CSharp examples for System.Drawing:Image Effect

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Description

Does basic edge detection on an image

Demo Code

/*// w w w . j a va  2 s  . c o m
Copyright (c) 2009 <a href="http://www.gutgames.com">James Craig</a>

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.*/
using System.Drawing.Imaging;
using System.Collections.Generic;
using System.Drawing.Drawing2D;
using System.Drawing;
using System;

public class Main{
        /// <summary>
        /// Does basic edge detection on an image
        /// </summary>
        /// <param name="Image">Image to do edge detection on</param>
        /// <param name="Threshold">Decides what is considered an edge</param>
        /// <param name="EdgeColor">Color of the edge</param>
        /// <returns>A bitmap which has the edges drawn on it</returns>
        public static Bitmap EdgeDetection(Bitmap Image, float Threshold, Color EdgeColor)
        {
            System.Drawing.Bitmap TempBitmap = Image;
            System.Drawing.Bitmap NewBitmap = new System.Drawing.Bitmap(TempBitmap.Width, TempBitmap.Height);
            System.Drawing.Graphics NewGraphics = System.Drawing.Graphics.FromImage(NewBitmap);
            NewGraphics.DrawImage(TempBitmap, new System.Drawing.Rectangle(0, 0, TempBitmap.Width, TempBitmap.Height), new System.Drawing.Rectangle(0, 0, TempBitmap.Width, TempBitmap.Height), System.Drawing.GraphicsUnit.Pixel);
            NewGraphics.Dispose();
            for (int x = 0; x < NewBitmap.Width; ++x)
            {
                for (int y = 0; y < NewBitmap.Height; ++y)
                {
                    bool EdgeSet = false;
                    Color CurrentColor = NewBitmap.GetPixel(x, y);
                    if (y < NewBitmap.Height - 1 && x < NewBitmap.Width - 1)
                    {
                        Color TempColor = NewBitmap.GetPixel(x + 1, y + 1);
                        if (Math.Sqrt(((CurrentColor.R - TempColor.R) * (CurrentColor.R - TempColor.R)) +
                            ((CurrentColor.G - TempColor.G) * (CurrentColor.G - TempColor.G)) +
                            ((CurrentColor.B - TempColor.B) * (CurrentColor.B - TempColor.B))) > Threshold)
                        {
                            NewBitmap.SetPixel(x, y, EdgeColor);
                        }
                        EdgeSet = true;
                    }
                    if (y < NewBitmap.Height - 1&&!EdgeSet)
                    {
                        Color TempColor = NewBitmap.GetPixel(x, y + 1);
                        if (Math.Sqrt(((CurrentColor.R - TempColor.R) * (CurrentColor.R - TempColor.R)) +
                            ((CurrentColor.G - TempColor.G) * (CurrentColor.G - TempColor.G)) +
                            ((CurrentColor.B - TempColor.B) * (CurrentColor.B - TempColor.B))) > Threshold)
                        {
                            NewBitmap.SetPixel(x, y, EdgeColor);
                        }
                        EdgeSet = true;
                    }
                    if (x < NewBitmap.Width - 1&&!EdgeSet)
                    {
                        Color TempColor = NewBitmap.GetPixel(x + 1, y);
                        if (Math.Sqrt(((CurrentColor.R - TempColor.R) * (CurrentColor.R - TempColor.R)) +
                            ((CurrentColor.G - TempColor.G) * (CurrentColor.G - TempColor.G)) +
                            ((CurrentColor.B - TempColor.B) * (CurrentColor.B - TempColor.B))) > Threshold)
                        {
                            NewBitmap.SetPixel(x, y, EdgeColor);
                        }
                        EdgeSet = true;
                    }
                }
            }
            return NewBitmap;
        }
        /// <summary>
        /// Does basic edge detection on an image
        /// </summary>
        /// <param name="FileName">Image to do edge detection on</param>
        /// <param name="Threshold">Decides what is considered an edge</param>
        /// <param name="EdgeColor">Color of the edge</param>
        /// <returns>A bitmap which has the edges drawn on it</returns>
        public static Bitmap EdgeDetection(string FileName, float Threshold, Color EdgeColor)
        {
            if (!IsGraphic(FileName))
                return new Bitmap(1, 1);
            System.Drawing.Image TempImage = System.Drawing.Image.FromFile(FileName);
            System.Drawing.Bitmap TempBitmap = new System.Drawing.Bitmap(TempImage, TempImage.Width, TempImage.Height);
            System.Drawing.Bitmap ReturnBitmap = Image.EdgeDetection(TempBitmap, Threshold, EdgeColor);
            TempBitmap.Dispose();
            TempImage.Dispose();
            return ReturnBitmap;
        }
        /// <summary>
        /// Does basic edge detection on an image
        /// </summary>
        /// <param name="FileName">Image to do edge detection on</param>
        /// <param name="NewFileName">Location to save the image to</param>
        /// <param name="Threshold">Decides what is considered an edge</param>
        /// <param name="EdgeColor">Color of the edge</param>
        public static void EdgeDetection(string FileName, string NewFileName, float Threshold,Color EdgeColor)
        {
            if (!IsGraphic(FileName))
                return;
            ImageFormat FormatUsing = GetFormat(NewFileName);
            System.Drawing.Bitmap NewBitmap = Image.EdgeDetection(FileName, Threshold, EdgeColor);
            NewBitmap.Save(NewFileName, FormatUsing);
            NewBitmap.Dispose();
        }
}

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