C#实现压缩图片
等比例压缩
/// <summary>
/// 压缩图片
/// </summary>
/// <param name="filePath">文件路径</param>
/// <param name="height">图像高度</param>
/// <returns></returns>
public static Image CompressPictures(string filePath, int height)
{
Image image = Image.Load(filePath);
if (height < image.Height)
{
image.Mutate(item => item.Resize(0, height));
}
return image;
}
缩略图
public static bool MakeThumbnail(string originalImagePath, string thumbnailPath, int width, int height, string mode)
{
bool f = false;
Image originalImage = Image.FromFile(originalImagePath);
int towidth = width;
int toheight = height;
int x = 0;
int y = 0;
int ow = originalImage.Width;
int oh = originalImage.Height;
switch (mode)
{
case "HW"://指定高宽缩放(可能变形)
break;
case "W"://指定宽,高按比例
toheight = originalImage.Height * width / originalImage.Width;
break;
case "H"://指定高,宽按比例
towidth = originalImage.Width * height / originalImage.Height;
break;
case "Cut"://指定高宽裁减(不变形)
if ((double)originalImage.Width / (double)originalImage.Height > (double)towidth / (double)toheight)
{
oh = originalImage.Height;
ow = originalImage.Height * towidth / toheight;
y = 0;
x = (originalImage.Width - ow) / 2;
}
else
{
ow = originalImage.Width;
oh = originalImage.Width * height / towidth;
x = 0;
y = (originalImage.Height - oh) / 2;
}
break;
default:
break;
}
//新建一个bmp图片
Image bitmap = new System.Drawing.Bitmap(towidth, toheight);
//新建一个画板
Graphics g = System.Drawing.Graphics.FromImage(bitmap);
//设置高质量插值法
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
//设置高质量,低速度呈现平滑程度
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
//清空画布并以透明背景色填充
g.Clear(Color.White);
//在指定位置并且按指定大小绘制原图片的指定部分
g.DrawImage(originalImage, new Rectangle(0, 0, towidth, toheight),
new Rectangle(x, y, ow, oh),
GraphicsUnit.Pixel);
try
{
//以jpg格式保存缩略图
bitmap.Save(thumbnailPath, System.Drawing.Imaging.ImageFormat.Jpeg);
f = true;
}
catch (System.Exception e)
{
f = false;
}
finally
{
originalImage.Dispose();
bitmap.Dispose();
g.Dispose();
}
return f;
}
本文来自博客园,作者:码农阿亮,转载请注明原文链接:https://www.cnblogs.com/wml-it/p/16427670.html
技术的发展日新月异,随着时间推移,无法保证本博客所有内容的正确性。如有误导,请大家见谅,欢迎评论区指正!
开源库地址,欢迎点亮:
GitHub:https://github.com/ITMingliang
Gitee: https://gitee.com/mingliang_it
GitLab: https://gitlab.com/ITMingliang
建群声明: 本着技术在于分享,方便大家交流学习的初心,特此建立【编程内功修炼交流群】,为大家答疑解惑。热烈欢迎各位爱交流学习的程序员进群,也希望进群的大佬能不吝分享自己遇到的技术问题和学习心得!进群方式:扫码关注公众号,后台回复【进群】。
![](https://images.cnblogs.com/cnblogs_com/wml-it/2196906/o_230823011905_wxgzhss.png)