Bitmap透明图片描边
作者：互联网
1 public static byte[] ToArray(this Bitmap bitmap)
2 {
3 var lockbits = bitmap.LockBits(new Rectangle(0, 0, bitmap.Width, bitmap.Height), ImageLockMode.ReadOnly, bitmap.PixelFormat);
4 byte[] bs = new byte[lockbits.Stride * lockbits.Height];
5 Marshal.Copy(lockbits.Scan0, bs, 0, lockbits.Stride * lockbits.Height);
6 return bs;
7 }
8
9 /// <summary>
10 /// 获取透明边缘坐标
11 /// </summary>
12 /// <param name="bitmap"></param>
13 /// <param name="overflow">是否允许坐标超出图片范围</param>
14 /// <returns></returns>
15 public static List<Point> GetVerge(this Bitmap bitmap, bool overflow = false)
16 {
17 List<Point> ps = new List<Point>();
18 byte[] arr = bitmap.ToArray();
19 int w = bitmap.Width;
20 int h = bitmap.Height;
21 int x = 0;
22 int y = 0;
23 int p = 3;
24 int s = w * 4;
25
26 #region x = 0
27 #region y = 0
28 if(arr[p] == 0)
29 {
30 if (arr[p + 4] > 0 ||
31 arr[p + s] > 0 || arr[p + s + 4] > 0)
32 ps.Add(new Point(x, y));
33 }
34 else if (overflow)
35 {
36 ps.Add(new Point(-1, -1));
37 ps.Add(new Point(0, -1));
38 ps.Add(new Point(1, -1));
39 ps.Add(new Point(-1, 0));
40 ps.Add(new Point(-1, 1));
41 }
42 #endregion
43 #region 0<y<h-1
44 for (y = 1; y < h - 1; y++)
45 {
46 p = 3 + s * y;
47 if(arr[p] == 0)
48 {
49 if (arr[p - s] > 0 || arr[p - s + 4] > 0 ||
50 arr[p + 4] > 0 ||
51 arr[p + s] > 0 || arr[p + s + 4] > 0)
52 ps.Add(new Point(x, y));
53 }
54 else if (overflow)
55 {
56 ps.Add(new Point(-1, y - 1));
57 ps.Add(new Point(-1, y));
58 ps.Add(new Point(-1, y + 1));
59 }
60 }
61 #endregion
62 #region y = h - 1
63 p = 3 + s * y;
64 if (arr[p] == 0)
65 {
66 if (arr[p - s] > 0 || arr[p - s + 4] > 0 ||
67 arr[p + 4] > 0)
68 ps.Add(new Point(x, y));
69 }
70 else if (overflow)
71 {
72 ps.Add(new Point(-1, y - 1));
73 ps.Add(new Point(-1, y));
74 ps.Add(new Point(-1, y + 1));
75 ps.Add(new Point(0, y + 1));
76 ps.Add(new Point(1, y + 1));
77 }
78 #endregion
79 #endregion
80
81 #region 0<x<w-1
82 for (x = 1; x < w - 1; x++)
83 {
84 #region y = 0
85 y = 0;
86 p = x * 4 + 3;
87 if (arr[p] == 0)
88 {
89 if (arr[p - 4] > 0 || arr[p + 4] > 0 ||
90 arr[p + s - 4] > 0 || arr[p + s] > 0 || arr[p + s + 4] > 0)
91 ps.Add(new Point(x, y));
92 }
93 else if (overflow)
94 {
95 ps.Add(new Point(x - 1, y - 1));
96 ps.Add(new Point(x, y - 1));
97 ps.Add(new Point(x + 1, y - 1));
98 }
99 #endregion
100 #region 0<y<h-1
101 for (y = 1; y < h - 1; y++)
102 {
103 p = x * 4 + 3 + s * y;
104 if (arr[p] == 0)
105 {
106 if (arr[p - s - 4] > 0 || arr[p - s] > 0 || arr[p - s + 4] > 0 ||
107 arr[p - 4] > 0 || arr[p + 4] > 0 ||
108 arr[p + s - 4] > 0 || arr[p + s] > 0 || arr[p + s + 4] > 0)
109 ps.Add(new Point(x, y));
110 }
111 }
112 #endregion
113 #region y = h - 1
114 p = x * 4 + 3 + s * y;
115 if (arr[p] == 0)
116 {
117 if (arr[p - s - 4] > 0 || arr[p - s] > 0 || arr[p - s + 4] > 0 ||
118 arr[p - 4] > 0 || arr[p + 4] > 0)
119 ps.Add(new Point(x, y));
120 }
121 else if (overflow)
122 {
123 ps.Add(new Point(x - 1, y + 1));
124 ps.Add(new Point(x, y + 1));
125 ps.Add(new Point(x + 1, y + 1));
126 }
127 #endregion
128 }
129 #endregion
130
131 #region x = w - 1
132 #region y = 0
133 x = w - 1;
134 y = 0;
135 p = x * 4 + 3;
136 if (arr[p] == 0)
137 {
138 if (arr[p - 4] > 0 ||
139 arr[p + s - 4] > 0 || arr[p + s] > 0)
140 ps.Add(new Point(x, y));
141 }
142 else if (overflow)
143 {
144 ps.Add(new Point(x - 1, y - 1));
145 ps.Add(new Point(x, y - 1));
146 ps.Add(new Point(x + 1, y - 1));
147 ps.Add(new Point(x + 1, y));
148 ps.Add(new Point(x + 1, y + 1));
149 }
150 #endregion
151 #region 0<y<h-1
152 for (y = 1; y < h - 1; y++)
153 {
154 p = x * 4 + 3 + s * y;
155 if (arr[p] == 0)
156 {
157 if (arr[p - s - 4] > 0 || arr[p - s] > 0 ||
158 arr[p - 4] > 0 ||
159 arr[p + s - 4] > 0 || arr[p + s] > 0)
160 ps.Add(new Point(x, y));
161 }
162 else if (overflow)
163 {
164 ps.Add(new Point(x + 1, y - 1));
165 ps.Add(new Point(x + 1, y));
166 ps.Add(new Point(x + 1, y + 1));
167 }
168 }
169 #endregion
170 #region y = h - 1
171 p = x * 4 + 3 + s * y;
172 if (arr[p] == 0)
173 {
174 if (arr[p - s - 4] > 0 || arr[p - s] > 0 ||
175 arr[p - 4] > 0)
176 ps.Add(new Point(x, y));
177 }
178 else if (overflow)
179 {
180 ps.Add(new Point(x + 1, y - 1));
181 ps.Add(new Point(x + 1, y));
182 ps.Add(new Point(x - 1, y + 1));
183 ps.Add(new Point(x, y + 1));
184 ps.Add(new Point(x + 1, y + 1));
185 }
186 #endregion
187 #endregion
188 return ps;
189 }
190
191 /// <summary>
192 /// 获取透明边缘坐标,返回只有描边的图片
193 /// </summary>
194 /// <param name="bitmap"></param>
195 /// <param name="overflow">是否允许坐标超出图片范围</param>
196 /// <returns></returns>
197 public static byte[] GetVerge1(this Bitmap bitmap, bool overflow = false)
198 {
199 int w = overflow ? bitmap.Width + 2 : bitmap.Width;
200 int h = overflow ? bitmap.Height + 2 : bitmap.Height;
201 int s = w * 4;
202 byte[] bs = new byte[s * h];
203 List<Point> ps = bitmap.GetVerge(overflow);
204 for (int i = 0; i < ps.Count; i++)
205 {
206 int x = overflow ? ps[i].X + 1 : ps[i].X;
207 int y = overflow ? ps[i].Y + 1 : ps[i].Y;
208 bs[x * 4 + s * y + 1] = 255;
209 bs[x * 4 + s * y + 3] = 255;
210 }
211 return bs;
212 }
标签：透明,arr,ps,Point,Bitmap,Add,描边,new,bitmap 来源： https://www.cnblogs.com/RedSky/p/16087830.html