服务器之家

服务器之家 > 正文

C#实现给图片加水印的方法

时间:2021-11-11 14:41     来源/作者:礼拜一

本文实例讲述了C#实现给图片加水印的方法。分享给大家供大家参考,具体如下:

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.Drawing.Drawing2D;
namespace Tutorial
{
  class WaterMark
  {
    [STAThread]
    static void Main(string[] args)
    {
      //set a working directory
      string WorkingDirectory = @"C:\Documents and Settings\administrator.JAZZMINE\My Documents\Projects\Tutorials\WaterMark";
      //define a string of text to use as the Copyright message
      string Copyright = "Copyright ?2002 - AP Photo/David Zalubowski";
      //create a image object containing the photograph to watermark
      Image imgPhoto = Image.FromFile(WorkingDirectory + "\\watermark_photo.jpg");
      int phWidth = imgPhoto.Width;
      int phHeight = imgPhoto.Height;
      //create a Bitmap the Size of the original photograph
      Bitmap bmPhoto = new Bitmap(phWidth, phHeight, PixelFormat.Format24bppRgb);
      bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);
      //load the Bitmap into a Graphics object
      Graphics grPhoto = Graphics.FromImage(bmPhoto);
      //create a image object containing the watermark
      Image imgWatermark = new Bitmap(WorkingDirectory + "\\watermark.bmp");
      int wmWidth = imgWatermark.Width;
      int wmHeight = imgWatermark.Height;
      //------------------------------------------------------------
      //Step #1 - Insert Copyright message
      //------------------------------------------------------------
      //Set the rendering quality for this Graphics object
      grPhoto.SmoothingMode = SmoothingMode.AntiAlias;
      //Draws the photo Image object at original size to the graphics object.
      grPhoto.DrawImage(
        imgPhoto,                // Photo Image object
        new Rectangle(0, 0, phWidth, phHeight), // Rectangle structure
        0,                   // x-coordinate of the portion of the source image to draw.
        0,                   // y-coordinate of the portion of the source image to draw.
        phWidth,                // Width of the portion of the source image to draw.
        phHeight,                // Height of the portion of the source image to draw.
        GraphicsUnit.Pixel);          // Units of measure
      //-------------------------------------------------------
      //to maximize the size of the Copyright message we will
      //test multiple Font sizes to determine the largest posible
      //font we can use for the width of the Photograph
      //define an array of point sizes you would like to consider as possiblities
      //-------------------------------------------------------
      int[] sizes = new int[]{16,14,12,10,8,6,4};
      Font crFont = null;
      SizeF crSize = new SizeF();
      //Loop through the defined sizes checking the length of the Copyright string
      //If its length in pixles is less then the image width choose this Font size.
      for (int i=0 ;i<7; i++)
      {
        //set a Font object to Arial (i)pt, Bold
        crFont = new Font("arial", sizes[i], FontStyle.Bold);
        //Measure the Copyright string in this Font
        crSize = grPhoto.MeasureString(Copyright, crFont);
        if((ushort)crSize.Width < (ushort)phWidth)
          break;
      }
      //Since all photographs will have varying heights, determine a
      //position 5% from the bottom of the image
      int yPixlesFromBottom = (int)(phHeight *.05);
      //Now that we have a point size use the Copyrights string height
      //to determine a y-coordinate to draw the string of the photograph
      float yPosFromBottom = ((phHeight - yPixlesFromBottom)-(crSize.Height/2));
      //Determine its x-coordinate by calculating the center of the width of the image
      float xCenterOfImg = (phWidth/2);
      //Define the text layout by setting the text alignment to centered
      StringFormat StrFormat = new StringFormat();
      StrFormat.Alignment = StringAlignment.Center;
      //define a Brush which is semi trasparent black (Alpha set to 153)
      SolidBrush semiTransBrush2 = new SolidBrush(Color.FromArgb(153, 0, 0, 0));
      //Draw the Copyright string
      grPhoto.DrawString(Copyright, //string of text
        crFont, //font
        semiTransBrush2, //Brush
        new PointF(xCenterOfImg+1,yPosFromBottom+1), //Position
        StrFormat);
      //define a Brush which is semi trasparent white (Alpha set to 153)
      SolidBrush semiTransBrush = new SolidBrush(Color.FromArgb(153, 255, 255, 255));
      //Draw the Copyright string a second time to create a shadow effect
      //Make sure to move this text 1 pixel to the right and down 1 pixel
      grPhoto.DrawString(Copyright, //string of text
        crFont, //font
        semiTransBrush, //Brush
        new PointF(xCenterOfImg,yPosFromBottom), //Position
        StrFormat); //Text alignment
      //------------------------------------------------------------
      //Step #2 - Insert Watermark image
      //------------------------------------------------------------
      //Create a Bitmap based on the previously modified photograph Bitmap
      Bitmap bmWatermark = new Bitmap(bmPhoto);
      bmWatermark.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);
      //Load this Bitmap into a new Graphic Object
      Graphics grWatermark = Graphics.FromImage(bmWatermark);
      //To achieve a transulcent watermark we will apply (2) color
      //manipulations by defineing a ImageAttributes object and
      //seting (2) of its properties.
      ImageAttributes imageAttributes = new ImageAttributes();
      //The first step in manipulating the watermark image is to replace
      //the background color with one that is trasparent (Alpha=0, R=0, G=0, B=0)
      //to do this we will use a Colormap and use this to define a RemapTable
      ColorMap colorMap = new ColorMap();
      //My watermark was defined with a background of 100% Green this will
      //be the color we search for and replace with transparency
      colorMap.OldColor = Color.FromArgb(255, 0, 255, 0);
      colorMap.NewColor = Color.FromArgb(0, 0, 0, 0);
      ColorMap[] remapTable = {colorMap};
      imageAttributes.SetRemapTable(remapTable, ColorAdjustType.Bitmap);
      //The second color manipulation is used to change the opacity of the
      //watermark. This is done by applying a 5x5 matrix that contains the
      //coordinates for the RGBA space. By setting the 3rd row and 3rd column
      //to 0.3f we achive a level of opacity
      float[][] colorMatrixElements = {
        new float[] {1.0f, 0.0f, 0.0f, 0.0f, 0.0f},
        new float[] {0.0f, 1.0f, 0.0f, 0.0f, 0.0f},
        new float[] {0.0f, 0.0f, 1.0f, 0.0f, 0.0f},
        new float[] {0.0f, 0.0f, 0.0f, 0.3f, 0.0f},
        new float[] {0.0f, 0.0f, 0.0f, 0.0f, 1.0f}};
      ColorMatrix wmColorMatrix = new ColorMatrix(colorMatrixElements);
      imageAttributes.SetColorMatrix(wmColorMatrix, ColorMatrixFlag.Default,
        ColorAdjustType.Bitmap);
      //For this example we will place the watermark in the upper right
      //hand corner of the photograph. offset down 10 pixels and to the
      //left 10 pixles
      int xPosOfWm = ((phWidth - wmWidth)-10);
      int yPosOfWm = 10;
      grWatermark.DrawImage(imgWatermark,
        new Rectangle(xPosOfWm,yPosOfWm,wmWidth,wmHeight), //Set the detination Position
        0, // x-coordinate of the portion of the source image to draw.
        0, // y-coordinate of the portion of the source image to draw.
        wmWidth, // Watermark Width
        wmHeight, // Watermark Height
        GraphicsUnit.Pixel, // Unit of measurment
        imageAttributes); //ImageAttributes Object
      //Replace the original photgraphs bitmap with the new Bitmap
      imgPhoto = bmWatermark;
      grPhoto.Dispose();
      grWatermark.Dispose();
      //save new image to file system.
      imgPhoto.Save(WorkingDirectory + "\\watermark_final.jpg", ImageFormat.Jpeg);
      imgPhoto.Dispose();
      imgWatermark.Dispose();
    }
  }
}

希望本文所述对大家C#程序设计有所帮助。

标签:

相关文章

热门资讯

yue是什么意思 网络流行语yue了是什么梗
yue是什么意思 网络流行语yue了是什么梗 2020-10-11
2020微信伤感网名听哭了 让对方看到心疼的伤感网名大全
2020微信伤感网名听哭了 让对方看到心疼的伤感网名大全 2019-12-26
背刺什么意思 网络词语背刺是什么梗
背刺什么意思 网络词语背刺是什么梗 2020-05-22
2021年耽改剧名单 2021要播出的59部耽改剧列表
2021年耽改剧名单 2021要播出的59部耽改剧列表 2021-03-05
苹果12mini价格表官网报价 iPhone12mini全版本价格汇总
苹果12mini价格表官网报价 iPhone12mini全版本价格汇总 2020-11-13
返回顶部