C# 无损图片压缩—— 基于Framework.40 类库实现

ゞ浴缸里的玫瑰 2024-02-18 14:17 30阅读 0赞

分为两部分，一个是操作类，另外一个是测试。直接上代码了

一、测试代码

private void button1\_Click(object sender, EventArgs e)  
\{  
string newSourcePath = ImgPath;//源图存放目录  
string newNewDir = MakePath; //新图存放目录

string sourceFile = Path.Combine(ImgPath, "app1.jpg"); //获取原图路径  
string newFile = string.Empty; //新图路径

ImgThumbnail iz = new ImgThumbnail();  
Action<ImgThumbnail.ImgThumbnailType> Thumbnail = (type =>  
\{  
//生成质量  
for (int i = 100; i >= 10; i -= 10)  
\{  
//计算新图路径，测试命名：原图名\_new\_缩放类型\_压缩质量.jpg  
newFile = Path.Combine(newNewDir, string.Format("app1\_new\_\{1\}\_\{0\}.jpg", i, type.ToString()));  
//压缩图片  
iz.Thumbnail(sourceFile, newFile, 100, 100, i, type);  
\}  
\});  
  
Thumbnail(ImgThumbnail.ImgThumbnailType.Cut);//裁剪压缩（裁剪压缩还不好用，待调整！）  
Thumbnail(ImgThumbnail.ImgThumbnailType.H); //以高度为参照压缩，不变形  
Thumbnail(ImgThumbnail.ImgThumbnailType.W); //以宽度为参照压缩，不变形  
Thumbnail(ImgThumbnail.ImgThumbnailType.WH); //固定宽高压缩，变形  
MessageBox.Show("完成");  
\}

二、操作类

using System.Drawing;  
using System.Drawing.Drawing2D;  
using System.Drawing.Imaging;

namespace MagickNet.App  
\{  
/// <summary>  
/// 图片压缩  
/// </summary>  
public class ImgThumbnail  
\{

\#region 枚举  
/// <summary>  
/// 指定缩放类型  
/// </summary>  
public enum ImgThumbnailType  
\{  
/// <summary>  
/// 无  
/// </summary>  
Nothing=0,  
/// <summary>  
/// 指定高宽缩放（可能变形）  
/// </summary>  
WH = 1,  
/// <summary>  
/// 指定宽，高按比例  
/// </summary>  
W = 2,  
/// <summary>  
/// 指定高，宽按比例  
/// </summary>  
H = 3,  
/// <summary>  
/// 指定高宽裁减（不变形）  
/// </summary>  
Cut = 4,  
/// <summary>  
/// 按照宽度成比例缩放后，按照指定的高度进行裁剪  
/// </summary>  
W\_HCut = 5,  
\}  
\#endregion

\#region Thumbnail

/// <summary>  
/// 无损压缩图片  
/// </summary>  
/// <param name="sourceFile">原图片</param>  
/// <param name="stream">压缩后保存到流中</param>  
/// <param name="height">高度</param>  
/// <param name="width"></param>  
/// <param name="quality">压缩质量 1-100</param>  
/// <param name="type">压缩缩放类型</param>  
/// <returns></returns>  
private static Bitmap Thumbnail(string sourceFile, int width, int height, int quality  
, ImgThumbnailType type, out ImageFormat tFormat)  
\{  
using (System.Drawing.Image iSource = System.Drawing.Image.FromFile(sourceFile))  
\{  
tFormat = iSource.RawFormat;  
//缩放后的宽度和高度  
int toWidth = width;  
int toHeight = height;  
//  
int x = 0;  
int y = 0;  
int oWidth = iSource.Width;  
int oHeight = iSource.Height;

switch (type)  
\{  
case ImgThumbnailType.WH://指定高宽缩放（可能变形）  
\{  
break;  
\}  
case ImgThumbnailType.W://指定宽，高按比例  
\{  
toHeight = iSource.Height \* width / iSource.Width;  
break;  
\}  
case ImgThumbnailType.H://指定高，宽按比例  
\{  
toWidth = iSource.Width \* height / iSource.Height;  
break;  
\}  
case ImgThumbnailType.Cut://指定高宽裁减（不变形）  
\{  
if ((double)iSource.Width / (double)iSource.Height > (double)toWidth / (double)toHeight)  
\{  
oHeight = iSource.Height;  
oWidth = iSource.Height \* toWidth / toHeight;  
y = 0;  
x = (iSource.Width - oWidth) / 2;  
\}  
else  
\{  
oWidth = iSource.Width;  
oHeight = iSource.Width \* height / toWidth;  
x = 0;  
y = (iSource.Height - oHeight) / 2;  
\}  
break;  
\}  
case ImgThumbnailType.W\_HCut://按照宽度成比例缩放后，按照指定的高度进行裁剪  
\{  
toHeight = iSource.Height \* width / iSource.Width;  
if (height < toHeight)  
\{  
oHeight = oHeight \* height / toHeight;  
toHeight = toHeight \* height / toHeight;  
\}  
break;  
\}  
default:  
break;  
\}

Bitmap ob = new Bitmap(toWidth, toHeight);  
//ImgWaterMark iwm = new ImgWaterMark();  
//iwm.AddWaterMark(ob, towidth, toheight, "[www.\*\*\*\*.com][www._.com]");  
Graphics g = Graphics.FromImage(ob);  
g.Clear(System.Drawing.Color.WhiteSmoke);  
g.CompositingQuality = CompositingQuality.HighQuality;  
g.SmoothingMode = SmoothingMode.HighQuality;  
g.InterpolationMode = InterpolationMode.HighQualityBicubic;  
g.DrawImage(iSource  
, new Rectangle(x, y, toWidth, toHeight)  
, new Rectangle(0, 0, oWidth, oHeight)  
, GraphicsUnit.Pixel);  
g.Dispose();

return ob;  
  
\}  
\}

\#endregion  
\}  
\}

转载请保留：http://write.blog.csdn.net/postedit/7715729

[www._.com]: http://www.iqingcao.com