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Change Color of Uploaded Image to Black and White


Hi

try this example to Change Color of Uploaded Image to Black and White

1- Create new website and add new page and New Folder and Name it Upload and inside this folder add another folder

and name it to Original

2- Open your Web page and add FileUpload and Button and Image control

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="ChangeImageColor.aspx.cs" Inherits="ChangeImageColor" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "<a href="http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd</a>">

<html xmlns="<a href="http://www.w3.org/1999/xhtml">http://www.w3.org/1999/xhtml</a>" >
<head runat="server">
    <title>Change Color Image to Black and White</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    <p>Please upload your picture:
    <asp:FileUpload id="PictureUploadControl" Width="400" runat="server" />       
    </p>
        <p>
    <asp:Button runat="server" id="AddPictureButton" text="Upload" onclick="AddPictureButton_Click" /><br />
        </p>

    <asp:Image ID="GrayscaledPhoto" runat="server" /><br />

    </div>
    </form>
</body>
</html>

3- In code behind add this code:-

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Drawing;  //Bitmap needed this
using System.Drawing.Imaging; //ImageFormat needed this
using System.IO; // .delete needed this
public partial class ChangeImageColor : System.Web.UI.Page
{
    public static Bitmap Grayscale(Bitmap bitmap)
    {
        //Declare myBitmap as a new Bitmap with the same Width & Height
        Bitmap myBitmap = new Bitmap(bitmap.Width, bitmap.Height);
        for (int i = 0; i < bitmap.Width; i++)
        {
            for (int x = 0; x < bitmap.Height; x++)
            {
                //Get the Pixel
                Color BitmapColor = bitmap.GetPixel(i, x);
                //I want to come back here at some point and understand, then change, the constants
                //Declare grayScale as the Grayscale Pixel
                int grayScale = (int)((BitmapColor.R * 0.3) + (BitmapColor.G * 0.59) + (BitmapColor.B * 0.11));
                //Declare myColor as a Grayscale Color
                Color myColor = Color.FromArgb(grayScale, grayScale, grayScale);
                //Set the Grayscale Pixel
                myBitmap.SetPixel(i, x, myColor);
            }
        }
        return myBitmap;
    }

    protected void AddPictureButton_Click(object sender, EventArgs e)
    {
        if (PictureUploadControl.HasFile)
        {
            PictureUploadControl.SaveAs(Server.MapPath("~/Upload/Original") + PictureUploadControl.FileName);
            Bitmap oldBitmap = new Bitmap(Server.MapPath("~/Upload/Original") + PictureUploadControl.FileName, false);
            Bitmap newBitmap = Grayscale(new Bitmap(oldBitmap));
            string name = Guid.NewGuid().ToString();
            newBitmap.Save(Server.MapPath("~/Upload/") + name + ".jpg", ImageFormat.Jpeg);
            oldBitmap.Dispose();
            //we will delete the old
           // File.Delete(Server.MapPath("~/Upload/Original") + PictureUploadControl.FileName);
            GrayscaledPhoto.ImageUrl = "Upload/" + name + ".jpg";
        }
    }

    protected void Page_Load(object sender, EventArgs e)
    {

    }
}

Hope this helps

Good Luck

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Categories: ASP.Net
  1. Boss BigName
    September 5, 2012 at 8:11 am

    thank you

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