C# 图片处理

按比例调整图片尺寸

 1 #region 按比例调整图片尺寸
 2 public static Bitmap GetThumbnail(Image bmp, int width, int height)
 3 {
 4     if (width == 0)
 5     {
 6         width = height * bmp.Width / bmp.Height;
 7     }
 8     if (height == 0)
 9     {
10         height = width * bmp.Height / bmp.Width;
11     }
12     Image imgSource = bmp;
13     Bitmap outBmp = new Bitmap(width, height);
14     Graphics g = Graphics.FromImage(outBmp);
15     g.Clear(Color.Transparent);
16     // 设置画布的描绘质量   
17     g.CompositingQuality = CompositingQuality.HighQuality;
18     g.SmoothingMode = SmoothingMode.HighQuality;
19     g.InterpolationMode = InterpolationMode.HighQualityBicubic;
20 
21     g.DrawImage(imgSource, new Rectangle(0, 0, width, height + 1), 0, 0, imgSource.Width, imgSource.Height, GraphicsUnit.Pixel);
22 
23     g.Dispose();
24     imgSource.Dispose();
25     bmp.Dispose();
26     return outBmp;
27 }
28 #endregion

按比例调整图片尺寸

合成图片

 1 /// <summary>
 2 /// 两种图片合并，类似相册，有个背景图，中间贴自己的目标图片        
 3 /// <param name="sourceImg">粘贴的源图片</param>
 4 /// <param name="destImg">粘贴的目标图片</param>
 5 /// <param name="name">合成图片存储路径</param>
 6 /// </summary>
 7 public void CombinImage(string sourceImg, string destImg, string name)
 8 {
 9     System.Drawing.Image imgBack = System.Drawing.Image.FromFile(sourceImg);     //相框图片 
10     System.Drawing.Image img = System.Drawing.Image.FromFile(destImg);        //照片图片
11 
12     Bitmap bmp = new Bitmap(imgBack.Width, imgBack.Height);
13 
14     Graphics g = Graphics.FromImage(bmp);
15     g.Clear(Color.White);
16     g.DrawImage(imgBack, 0, 0, imgBack.Width, imgBack.Height);
17     //g.FillRectangle(System.Drawing.Brushes.Black, 16, 16, (int)112 + 2, ((int)73 + 2));//相片四周刷一层黑色边框
18 
19     //g.DrawImage(img, 照片与相框的左边距, 照片与相框的上边距, 照片宽, 照片高);
20     g.DrawImage(img, imgBack.Width / 2 - img.Width / 2 + 0, imgBack.Height / 2 - img.Height / 2 + 0, img.Width, img.Height);
21     GC.Collect();
22 
23     //保存指定格式图片
24     bmp.Save(name, ImageFormat.Png);    
25 }

合成图片

合成前：

合成后：