C#清晰的图片缩略方案_.net教程网 http://www.soaspx.com/dotnet/csharp/csharp_20091118_1677.html
希望这篇文章能给对于需要经常生成缩略图的朋友提供帮助!
购吧网目前拥有4000余种商品,在售商品超过2000万,其中图片量截至目前已有8G。 目前我们的方案是用单独的文件服务器存放商品的图片,通过file.365goba.com访问。 文件服务器上架一个用于上传图片的WCF服务对上传的图片进行缩略并保存。
购吧网前期的缩略算法用的是网略上广泛流传的三线性插值算法(效果并不是很好),代码如下:
using System; using System.Drawing; using System.IO; using System.Drawing.Imaging; using System.Drawing.Drawing2D;
namespace Ants.Tools {
public class Image {
public int Width { get; set; }
public int Height { get; set; }
private Image() { } public Image(int width, int height) { this.Width = width; this.Height = height; }
public MemoryStream getHightThumb(Stream imgData, string Mode_HW_W_H_Cut) { MemoryStream result = new MemoryStream(); System.Drawing.Image.GetThumbnailImageAbort myCallBack = new System.Drawing.Image.GetThumbnailImageAbort(ThumbnailCallBack); try { System.Drawing.Image originalImage = System.Drawing.Image.FromStream(imgData);
int X, Y; X = Width; Y = Height;
int towidth = X; int toheight = Y;
int x = 0; int y = 0; int ow = originalImage.Width; int oh = originalImage.Height;
switch (Mode_HW_W_H_Cut) { 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 * X / originalImage.Width; break; case "H//指定高,宽按比例 towidth = originalImage.Width * Y / originalImage.Height; break; case "Cut": 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 * Y / towidth; x = 0; y = (originalImage.Height - oh) / 2; } break; default: break; }
System.Drawing.Image bitmap = new System.Drawing.Bitmap(towidth, toheight);
System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmap);
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
g.Clear(System.Drawing.Color.Transparent);
g.DrawImage(originalImage, new System.Drawing.Rectangle(0, 0, towidth, toheight), new System.Drawing.Rectangle(x, y, ow, oh), System.Drawing.GraphicsUnit.Pixel); bitmap.Save(result, System.Drawing.Imaging.ImageFormat.Jpeg);
} catch { //do something } return result; } } }
|
此算法可以满足一般的网站的需求,但是作为一个电子商务网站,商品的图片的清晰度直接影响到消费都对此商品的购买欲望。
为了找到更好的方案,终于让我们找到了一个好的组件:MagickNet 这个组件是用C++写的,不过网络上已经有可用的C#调用版,文章的
后我也会给出这个DLL文件,值得一提的是这个组件是开源的。大家可以去研究下。
MagickNet 的功能很多,我这里就贴出一下他的缩略方法的用法(MagickNet 的资料在网上很难早)
using System;
using System.Collections.Generic;
using System.Text;
namespace KeChenDLL
{
public class UploadFile
{
private string _path;//要处理的图片(原图)地址
public UploadFile(string path)
{
this._path = path;
}
private UploadFile()
{
}
public void ReSize(int width, int height,string SaveToPath)
{
MagickNet.Image img = new MagickNet.Image(_path);
img.Quality = 100;
System.Drawing.Bitmap bitmap = new System.Drawing.Bitmap(_path);
int x = bitmap.Width;
int y = bitmap.Height;
float rank = (float) x/y;
if (x > y)
{
height =Convert.ToInt32(height / rank);
}
else
{
width =Convert.ToInt32(width * rank);
}
img.Resize(new System.Drawing.Size(width, height));
img.Write(SaveToPath);
img.Dispose();
}
}
}
内容来自用户分享和网络整理,不保证内容的准确性,如有侵权内容,可联系管理员处理
|