(原創) 如何将图片以对角线做映射(Mirror)? (.NET) (ASP.NET) (C#) (GDI+) (Image Processing)
这是我修Computer Vision的作业，此源代码也示范出如何Pixel By Pixel的方式编辑图片以及如何读取indexd的bmp图片格式。
1
<%@ Page Language="C#" %>
2
3<%@ Import Namespace="System.Drawing" %>
4<%@ Import Namespace="System.Drawing.Imaging" %>
5<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
6
7<script runat="server">
8
/// <summary>
9 /// Diagonally mirrored lena.bmp
10 /// </summary>
11 /// <remarks>
12 /// .NET Framework 2.0 can't draw indexd pixel format directly.
13 /// and will get
14 /// "A Graphics object cannot be created from an image that "
15 /// has an indexed pixel format." exception.
16 /// So we have to make a temporary bitmap, and manually draw
17 /// indexed pixel format to general bitmap.
18 ///</remarks>
19
protected void Page_Load(object sender, EventArgs e) {
20 // Bitmap uses System.Drawing namespace.
21 Bitmap bmp = new Bitmap(Server.MapPath("lena.bmp"));
22
23 // Size the new bitmap to source bitmap's dimension.
24 Bitmap _bmp = new Bitmap(bmp.Width, bmp.Height);
25
26 // Uses temp _bmp to write on canvas.
27 Graphics canvas = Graphics.FromImage(_bmp);
28
29 // Draw the old bitmap's content to the new bitmap.
30 // Paint the entire region of old bitmap to the new bitmap.
31 // Use the rectangle type to select area of source image.
32 canvas.DrawImage(bmp, new Rectangle(0, 0, _bmp.Width, _bmp.Height), 0, 0, bmp.Width, bmp.Height, GraphicsUnit.Pixel);
33
34 // Make temp _bmp to general bmp.
35 bmp = _bmp;
36
37 // Make a new bitmap for Diagonally mirrored.
38 Bitmap bmpDiagonallyMirrored = new Bitmap(bmp.Width, bmp.Height);
39
40 int r = 0, g = 0, b = 0; // R,G,B for Original bmp's RGB value.
41 int tarX = 0; // avgX for average X-axle value.
42 int tarY = 0; // tarX for Rightside-left X-axle value.
43
44 // Pixel by pixcel image processing.
45 for (int x = 0; x < bmp.Width; x++) {
46 for (int y = 0; y < bmp.Height; y++) {
47 // Get RGB from original bitmap.
48 r = bmp.GetPixel(x, y).R;
49 g = bmp.GetPixel(x, y).G;
50 b = bmp.GetPixel(x, y).B;
51
52 // Cause x + y = 512 is diagonal line for lena.bmp
53 tarX = 512 - y;
54 tarY = 512 - x;
55
56 // Write to new Diagonally mirrored bitmap on specified pixel and RGB.
57 bmpDiagonallyMirrored.SetPixel(tarX - 1, tarY - 1, Color.FromArgb(r, g, b));
58
}
59 }
60
61 // Specify HTML's content type.
62 Response.Clear();
63 Response.ContentType = "image/bmp";
64
65 // ImageFormat uses System.Drawing.Imaging namespace.
66 // Must use ImageFormat.Jpeg. If use ImageFormat.Bmp,
67 // you'll get "System.Runtime.InteropServices.ExternalException: A generic error occurred in GDI+." error.
68 bmpDiagonallyMirrored.Save(Response.OutputStream, ImageFormat.Jpeg);
69
70 // You should always call the Dispose method to release
71 // the Graphics and related resources created by the
72 // FromImage method.
73 _bmp.Dispose();
74 bmp.Dispose();
75 bmpDiagonallyMirrored.Dispose();
76 canvas.Dispose();
77
}
78</script>
79
80<html xmlns="http://www.w3.org/1999/xhtml" >
81<head runat="server">
82 <title>Untitled Page</title>
83</head>
84<body>
85 <form id="form1" runat="server">
86 <div>
87
88 </div>
89 </form>
90</body>
91</html>
92
<%@ Page Language="C#" %>
2
3
<%@ Import Namespace="System.Drawing" %>4
<%@ Import Namespace="System.Drawing.Imaging" %>5
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">6
7
<script runat="server">8
/// <summary>9
/// Diagonally mirrored lena.bmp 10
/// </summary>11
/// <remarks>12
/// .NET Framework 2.0 can't draw indexd pixel format directly.13
/// and will get 14
/// "A Graphics object cannot be created from an image that " 15
/// has an indexed pixel format." exception.16
/// So we have to make a temporary bitmap, and manually draw 17
/// indexed pixel format to general bitmap. 18
///</remarks>19
protected void Page_Load(object sender, EventArgs e) {
20
// Bitmap uses System.Drawing namespace.21
Bitmap bmp = new Bitmap(Server.MapPath("lena.bmp"));22
23
// Size the new bitmap to source bitmap's dimension.24
Bitmap _bmp = new Bitmap(bmp.Width, bmp.Height);25
26
// Uses temp _bmp to write on canvas.27
Graphics canvas = Graphics.FromImage(_bmp);28
29
// Draw the old bitmap's content to the new bitmap.30
// Paint the entire region of old bitmap to the new bitmap.31
// Use the rectangle type to select area of source image.32
canvas.DrawImage(bmp, new Rectangle(0, 0, _bmp.Width, _bmp.Height), 0, 0, bmp.Width, bmp.Height, GraphicsUnit.Pixel);33
34
// Make temp _bmp to general bmp.35
bmp = _bmp;36
37
// Make a new bitmap for Diagonally mirrored.38
Bitmap bmpDiagonallyMirrored = new Bitmap(bmp.Width, bmp.Height);39
40
int r = 0, g = 0, b = 0; // R,G,B for Original bmp's RGB value.41
int tarX = 0; // avgX for average X-axle value.42
int tarY = 0; // tarX for Rightside-left X-axle value.43
44
// Pixel by pixcel image processing.45
for (int x = 0; x < bmp.Width; x++) {46
for (int y = 0; y < bmp.Height; y++) {47
// Get RGB from original bitmap.48
r = bmp.GetPixel(x, y).R;49
g = bmp.GetPixel(x, y).G;50
b = bmp.GetPixel(x, y).B;51
52
// Cause x + y = 512 is diagonal line for lena.bmp53
tarX = 512 - y;54
tarY = 512 - x;55
56
// Write to new Diagonally mirrored bitmap on specified pixel and RGB.57
bmpDiagonallyMirrored.SetPixel(tarX - 1, tarY - 1, Color.FromArgb(r, g, b));58
}59
}60
61
// Specify HTML's content type.62
Response.Clear();63
Response.ContentType = "image/bmp";64
65
// ImageFormat uses System.Drawing.Imaging namespace.66
// Must use ImageFormat.Jpeg. If use ImageFormat.Bmp,67
// you'll get "System.Runtime.InteropServices.ExternalException: A generic error occurred in GDI+." error.68
bmpDiagonallyMirrored.Save(Response.OutputStream, ImageFormat.Jpeg);69
70
// You should always call the Dispose method to release 71
// the Graphics and related resources created by the 72
// FromImage method.73
_bmp.Dispose();74
bmp.Dispose();75
bmpDiagonallyMirrored.Dispose();76
canvas.Dispose();77
}78
</script>79
80
<html xmlns="http://www.w3.org/1999/xhtml" >81
<head runat="server">82
<title>Untitled Page</title>83
</head>84
<body>85
<form id="form1" runat="server">86
<div>87
88
</div>89
</form>90
</body>91
</html>92
