C#图片水印代码整理
这一段公司有个项目，客户要求上传的图片要带上自定义的水印。以前也经常和朋友讨论C#图片水印方面的问题，但是从来没有实际操作过。所以，借这次项目的机会也研究了一下C#图片水印的功能！本人参考的是discuz论坛中的代码。这种方法是直接把要上传的图片先转化成System.Drawing.Image，而不用保存到服务器端的磁盘上，然后加上水印重新绘制，再保存到服务器端的磁盘上，下面就拿出来晒晒：
1
///
<summary>
2
///
加图片水印
3
///
</summary>
4
///
<param name="img">
要加水印的原图(System.Drawing)
</param>
5
///
<param name="filename">
文件名
</param>
6
///
<param name="watermarkFilename">
水印文件名
</param>
7
///
<param name="watermarkStatus">
图片水印位置1=左上 2=中上 3=右上 4=左中 5=中中 6=右中 7=左下 8=右中 9=右下
</param>
8
///
<param name="quality">
加水印后的质量0~100,数字越大质量越高
</param>
9
///
<param name="watermarkTransparency">
水印图片的透明度1~10,数字越小越透明,10为不透明
</param>
10
public
static
void
ImageWaterMarkPic(Image img,
string
filename,
string
watermarkFilename,
int
watermarkStatus,
int
quality,
int
watermarkTransparency)
11
{
12
Graphics g
=
Graphics.FromImage(img);
13
//
设置高质量插值法
14
//
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
15
//
设置高质量,低速度呈现平滑程度
16
//
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
17
Image watermark
=
new
Bitmap(watermarkFilename);
18
19
if
(watermark.Height
>=
img.Height
||
watermark.Width
>=
img.Width)
20
return
;
21
22
ImageAttributes imageAttributes
=
new
ImageAttributes();
23
ColorMap colorMap
=
new
ColorMap();
24
25
colorMap.OldColor
=
Color.FromArgb(
255
,
0
,
255
,
0
);
26
colorMap.NewColor
=
Color.FromArgb(
0
,
0
,
0
,
0
);
27
ColorMap[] remapTable
=
{ colorMap };
28
29
imageAttributes.SetRemapTable(remapTable, ColorAdjustType.Bitmap);
30
31
float
transparency
=
0.5F
;
32
if
(watermarkTransparency
>=
1
&&
watermarkTransparency
<=
10
)
33
transparency
=
(watermarkTransparency
/
10.0F
);
34
35
36
float
[][] colorMatrixElements
=
{
37
new
float
[] {
1.0f
,
0.0f
,
0.0f
,
0.0f
,
0.0f
},
38
new
float
[] {
0.0f
,
1.0f
,
0.0f
,
0.0f
,
0.0f
},
39
new
float
[] {
0.0f
,
0.0f
,
1.0f
,
0.0f
,
0.0f
},
40
new
float
[] {
0.0f
,
0.0f
,
0.0f
, transparency,
0.0f
},
41
new
float
[] {
0.0f
,
0.0f
,
0.0f
,
0.0f
,
1.0f
}
42
};
43
44
ColorMatrix colorMatrix
=
new
ColorMatrix(colorMatrixElements);
45
46
imageAttributes.SetColorMatrix(colorMatrix, ColorMatrixFlag.Default, ColorAdjustType.Bitmap);
47
48
int
xpos
=
0
;
49
int
ypos
=
0
;
50
51
switch
(watermarkStatus)
52
{
53
case
1
:
54
xpos
=
(
int
)(img.Width
*
(
float
).
01
);
55
ypos
=
(
int
)(img.Height
*
(
float
).
01
);
56
break
;
57
case
2
:
58
xpos
=
(
int
)((img.Width
*
(
float
).
50
)
-
(watermark.Width
/
2
));
59
ypos
=
(
int
)(img.Height
*
(
float
).
01
);
60
break
;
61
case
3
:
62
xpos
=
(
int
)((img.Width
*
(
float
).
99
)
-
(watermark.Width));
63
ypos
=
(
int
)(img.Height
*
(
float
).
01
);
64
break
;
65
case
4
:
66
xpos
=
(
int
)(img.Width
*
(
float
).
01
);
67
ypos
=
(
int
)((img.Height
*
(
float
).
50
)
-
(watermark.Height
/
2
));
68
break
;
69
case
5
:
70
xpos
=
(
int
)((img.Width
*
(
float
).
50
)
-
(watermark.Width
/
2
));
71
ypos
=
(
int
)((img.Height
*
(
float
).
50
)
-
(watermark.Height
/
2
));
72
break
;
73
case
6
:
74
xpos
=
(
int
)((img.Width
*
(
float
).
99
)
-
(watermark.Width));
75
ypos
=
(
int
)((img.Height
*
(
float
).
50
)
-
(watermark.Height
/
2
));
76
break
;
77
case
7
:
78
xpos
=
(
int
)(img.Width
*
(
float
).
01
);
79
ypos
=
(
int
)((img.Height
*
(
float
).
99
)
-
watermark.Height);
80
break
;
81
case
8
:
82
xpos
=
(
int
)((img.Width
*
(
float
).
50
)
-
(watermark.Width
/
2
));
83
ypos
=
(
int
)((img.Height
*
(
float
).
99
)
-
watermark.Height);
84
break
;
85
case
9
:
86
xpos
=
(
int
)((img.Width
*
(
float
).
99
)
-
(watermark.Width));
87
ypos
=
(
int
)((img.Height
*
(
float
).
99
)
-
watermark.Height);
88
break
;
89
}
90
91
g.DrawImage(watermark,
new
Rectangle(xpos, ypos, watermark.Width, watermark.Height),
0
,
0
, watermark.Width, watermark.Height, GraphicsUnit.Pixel, imageAttributes);
92
93
ImageCodecInfo[] codecs
=
ImageCodecInfo.GetImageEncoders();
94
ImageCodecInfo ici
=
null
;
95
foreach
(ImageCodecInfo codec
in
codecs)
96
{
97
if
(codec.MimeType.IndexOf(
"
jpeg
"
)
>
-
1
)
98
ici
=
codec;
99
}
100
EncoderParameters encoderParams
=
new
EncoderParameters();
101
long
[] qualityParam
=
new
long
[
1
];
102
if
(quality
<
0
||
quality
>
100
)
103
quality
=
80
;
104
105
qualityParam[
0
]
=
quality;
106
107
EncoderParameter encoderParam
=
new
EncoderParameter(System.Drawing.Imaging.Encoder.Quality, qualityParam);
108
encoderParams.Param[
0
]
=
encoderParam;
109
110
if
(ici
!=
null
)
111
img.Save(filename, ici, encoderParams);
112
else
113
img.Save(filename);
114
115
g.Dispose();
116
img.Dispose();
117
watermark.Dispose();
118
imageAttributes.Dispose();
119
}
120
121
///
<summary>
122
///
增加图片文字水印
123
///
</summary>
124
///
<param name="img">
要加水印的原图(System.Drawing)
</param>
125
///
<param name="filename">
文件名
</param>
126
///
<param name="watermarkText">
水印文字
</param>
127
///
<param name="watermarkStatus">
图片水印位置1=左上 2=中上 3=右上 4=左中 5=中中 6=右中 7=左下 8=右中 9=右下
</param>
128
///
<param name="quality">
加水印后的质量0~100,数字越大质量越高
</param>
129
///
<param name="fontname">
水印的字体
</param>
130
///
<param name="fontsize">
水印的字号
</param>
131
public
static
void
ImageWaterMarkText(Image img,
string
filename,
string
watermarkText,
int
watermarkStatus,
int
quality,
string
fontname,
int
fontsize)
132
{
133
Graphics g
=
Graphics.FromImage(img);
134
Font drawFont
=
new
Font(fontname, fontsize, FontStyle.Regular, GraphicsUnit.Pixel);
135
SizeF crSize;
136
crSize
=
g.MeasureString(watermarkText, drawFont);
137
138
float
xpos
=
0
;
139
float
ypos
=
0
;
140
141
switch
(watermarkStatus)
142
{
143
case
1
:
144
xpos
=
(
float
)img.Width
*
(
float
).
01
;
145
ypos
=
(
float
)img.Height
*
(
float
).
01
;
146
break
;
147
case
2
:
148
xpos
=
((
float
)img.Width
*
(
float
).
50
)
-
(crSize.Width
/
2
);
149
ypos
=
(
float
)img.Height
*
(
float
).
01
;
150
break
;
151
case
3
:
152
xpos
=
((
float
)img.Width
*
(
float
).
99
)
-
crSize.Width;
153
ypos
=
(
float
)img.Height
*
(
float
).
01
;
154
break
;
155
case
4
:
156
xpos
=
(
float
)img.Width
*
(
float
).
01
;
157
ypos
=
((
float
)img.Height
*
(
float
).
50
)
-
(crSize.Height
/
2
);
158
break
;
159
case
5
:
160
xpos
=
((
float
)img.Width
*
(
float
).
50
)
-
(crSize.Width
/
2
);
161
ypos
=
((
float
)img.Height
*
(
float
).
50
)
-
(crSize.Height
/
2
);
162
break
;
163
case
6
:
164
xpos
=
((
float
)img.Width
*
(
float
).
99
)
-
crSize.Width;
165
ypos
=
((
float
)img.Height
*
(
float
).
50
)
-
(crSize.Height
/
2
);
166
break
;
167
case
7
:
168
xpos
=
(
float
)img.Width
*
(
float
).
01
;
169
ypos
=
((
float
)img.Height
*
(
float
).
99
)
-
crSize.Height;
170
break
;
171
case
8
:
172
xpos
=
((
float
)img.Width
*
(
float
).
50
)
-
(crSize.Width
/
2
);
173
ypos
=
((
float
)img.Height
*
(
float
).
99
)
-
crSize.Height;
174
break
;
175
case
9
:
176
xpos
=
((
float
)img.Width
*
(
float
).
99
)
-
crSize.Width;
177
ypos
=
((
float
)img.Height
*
(
float
).
99
)
-
crSize.Height;
178
break
;
179
}
180
181
//
g.DrawString(watermarkText, drawFont, new SolidBrush(Color.White), xpos + 1, ypos + 1);文字阴影
182
g.DrawString(watermarkText, drawFont,
new
SolidBrush(Color.Black), xpos, ypos);
183
184
ImageCodecInfo[] codecs
=
ImageCodecInfo.GetImageEncoders();
185
ImageCodecInfo ici
=
null
;
186
foreach
(ImageCodecInfo codec
in
codecs)
187
{
188
if
(codec.MimeType.IndexOf(
"
jpeg
"
)
>
-
1
)
189
ici
=
codec;
190
}
191
EncoderParameters encoderParams
=
new
EncoderParameters();
192
long
[] qualityParam
=
new
long
[
1
];
193
if
(quality
<
0
||
quality
>
100
)
194
quality
=
80
;
195
196
qualityParam[
0
]
=
quality;
197
198
EncoderParameter encoderParam
=
new
EncoderParameter(System.Drawing.Imaging.Encoder.Quality, qualityParam);
199
encoderParams.Param[
0
]
=
encoderParam;
200
201
if
(ici
!=
null
)
202
img.Save(filename, ici, encoderParams);
203
else
204
img.Save(filename);
205
206
g.Dispose();
207
img.Dispose();
208
}
209
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