(原創) 如何用程序的方式载入jpg图形文件? (.NET) (GDI+) (ASP.NET) (Image Processing)
Abstract
虽然HTML本身就提供了tag可直接显示jpg图形文件，但若需对图形本身作Pixel By Pixel的影像处理，如『影像辨识』，就必须用程序的方式将jpg图形文件加载，然后才能做后续的处理，以下的程序将示范如何在.NET平台使用C#载入jpg图形文件。
Introduction
1
<!-- (C) OOMusou 2006.09.29 oomusou@hotmail.com-->
2
<%@ Page Language="C#" %>
3
4<%@ Import Namespace="System.Drawing" %>
5<%@ Import Namespace="System.Drawing.Imaging" %>
6<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
7
8<script runat="server">
9
/// <summary>
10 /// Demo how to read image from Jpeg format for further
11 /// image processing.
12 /// </summary>
13
protected void Page_Load(object sender, EventArgs e) {
14
15 // Bitmap uses System.Drawing namespace.
16 Bitmap jpg = new Bitmap(Server.MapPath("lena.jpg"));
17
18 // Graphics uses System.Drawing namespace.
19 Graphics canvas = Graphics.FromImage(jpg);
20
21 // Specify HTML's content type.
22 Response.Clear();
23 Response.ContentType = "image/jpeg";
24
25 // ImageFormat uses System.Drawing.Imaging namespace.
26 jpg.Save(Response.OutputStream, ImageFormat.Jpeg);
27
28 // You should always call the Dispose method to release
29 // the Graphics and related resources created by the
30 // FromImage method.
31 jpg.Dispose();
32 canvas.Dispose();
33
}
34</script>
35
36<html xmlns="http://www.w3.org/1999/xhtml">
37<head runat="server">
38 <title></title>
39</head>
40<body>
41 <form id="form1" runat="server">
42 <div>
43 </div>
44 </form>
45</body>
46</html>
47
<!-- (C) OOMusou 2006.09.29 oomusou@hotmail.com-->2
<%@ Page Language="C#" %>
3
4
<%@ Import Namespace="System.Drawing" %>5
<%@ Import Namespace="System.Drawing.Imaging" %>6
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">7
8
<script runat="server">9
/// <summary>10
/// Demo how to read image from Jpeg format for further 11
/// image processing. 12
/// </summary>13
protected void Page_Load(object sender, EventArgs e) {
14
15
// Bitmap uses System.Drawing namespace.16
Bitmap jpg = new Bitmap(Server.MapPath("lena.jpg"));17
18
// Graphics uses System.Drawing namespace.19
Graphics canvas = Graphics.FromImage(jpg);20
21
// Specify HTML's content type.22
Response.Clear();23
Response.ContentType = "image/jpeg";24
25
// ImageFormat uses System.Drawing.Imaging namespace.26
jpg.Save(Response.OutputStream, ImageFormat.Jpeg);27
28
// You should always call the Dispose method to release 29
// the Graphics and related resources created by the 30
// FromImage method.31
jpg.Dispose();32
canvas.Dispose();33
}34
</script>35
36
<html xmlns="http://www.w3.org/1999/xhtml">37
<head runat="server">38
<title></title>39
</head>40
<body>41
<form id="form1" runat="server">42
<div>43
</div>44
</form>45
</body>46
</html>47
See Also
(原創) 如何使用ANSI C/ISO C++讀寫24位元的bmp圖檔? (初級) (C/C++)
(原創) 如何使用ANSI C讀寫32位元的BMP圖檔? (C/C++) (C) (Image Processing)
(原創) 如何使用ANSI C讀寫24/32位元的BMP圖檔? (C/C++) (C) (Image Processing)
(原創) 如何使用C++/CLI读/写jpg檔? (初级) (C++/CLI)
Reference
Steven A. Smith, Rob Howard, The ASP Alliance, ASP.NET 开发手札, 上奇科技出版事业处
