How to implement watermarking in ES0en. net

The watermark is to prevent us from stealing our images.

Two ways to achieve watermark effect

1) Watermark can be added when the user uploads.

a) Benefits: The server sends the image directly to the customer each time the user reads it, as opposed to the two methods.

Faults: corrupted original image.

2) Through the global 1 general processor, when the user requests the image, add watermark.

a) Benefit: The original image is not destroyed

b) Disadvantages: Every time the user requests, the requested image needs to be watermarked, which wastes the resources of the server.

Code to achieve the second way:

 
using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Web; 
using System.Drawing; 
using System.IO; 

namespace BookShop.Web 
{ 
public class WaterMark : IHttpHandler 
{ 

private const string WATERMARK_URL = "~/Images/watermark.jpg"; // The watermark image  
private const string DEFAULTIMAGE_URL = "~/Images/default.jpg";<span style="white-space:pre"> </span> // The default image  
#region IHttpHandler  Members of the  

public bool IsReusable 
{ 
get { return false; } 
} 

public void ProcessRequest(HttpContext context) 
{ 

//context.Request.PhysicalPath // Gets the physical path to the file requested by the user  

System.Drawing.Image Cover; 
// Determines whether a file exists in the physical path of the request  
if (File.Exists(context.Request.PhysicalPath)) 
{ 
// Load the file  
Cover = Image.FromFile(context.Request.PhysicalPath); 
// Loaded watermark image  
Image watermark = Image.FromFile(context.Request.MapPath(WATERMARK_URL)); 
// Get a drawing image from the book cover  
Graphics g = Graphics.FromImage(Cover); 
// in image Watermark on top  
g.DrawImage(watermark, new Rectangle(Cover.Width - watermark.Width, Cover.Height - watermark.Height, 

 
watermark.Width, watermark.Height), 0, 0, watermark.Width, watermark.Height, GraphicsUnit.Pixel); 
// The release of the canvas  
g.Dispose(); 
// Release watermark image  
watermark.Dispose(); 
} 
else 
{ 
// Load the default image  
Cover = Image.FromFile(context.Request.MapPath(DEFAULTIMAGE_URL)); 
} 
// Set the output format  
context.Response.ContentType = "image/jpeg"; 
// Store the image in the output stream  
Cover.Save(context.Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg); 
Cover.Dispose(); 
context.Response.End(); 
} 

#endregion 
} 
}