Generating image thumbnails in ASP.NET?

Question

What is the fastest and more reliable way of generating thumbnails in .NET? I need to get any image, compress it in JPEG and resize it.

I\'ve seen several examples w

Answer 1

I use ImageMagick for photo processing

UPDATED

Model:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.IO;
using ImageMagickObject;

namespace photostorage.Models
{
    public class PhotoProcessing
    {
        public MagickImage ResizeImg(string filepath, string filename)
        {
            Object[] rotate = new Object[] { filepath + "/" + filename, 
                "-auto-orient", filepath + "/" + filename };
            Object[] big = new Object[] { filepath + "/" + filename, 
                "-resize", "800", filepath + "/" + "big_" + filename };
            Object[] middle = new Object[] { filepath + "/big_" + filename, 
                "-resize", "400", filepath + "/" + "mid_" + filename };
            Object[] small = new Object[] { filepath + "/mid_" + filename, 
                "-resize", "200", filepath + "/" + "small_" + filename };
            Object[] crop = new Object[] { filepath + "/small_" + filename, 
                "-resize", "50", filepath + "/" + "crop_" + filename };
            ImageMagickObject.MagickImage img = 
                new ImageMagickObject.MagickImage();
            img.Convert(rotate);
            img.Convert(big);
            img.Convert(middle);
            img.Convert(small);
            img.Convert(crop);
            return img;
        }
    }
}

Controller:

PhotoProcessing resizeImg = new PhotoProcessing();
[HttpPost]
public string Index(params,params,params...)
{
    var GetResize = resizeImg.ResizeImg(
        destinationFolder + "/" + curFolder, fullFileName);
}

Answer 2

I am using Aurigma Image Uploader tool. it's pretty nice control. but it is paid you can check aurigma

Answer 3

I can't say whether this is the most efficient manner, but here is a snippet of code I wrote to produce 3 smaller images from a large image:

  private void GenerateImages(byte[] data, string extension, string filename)
  {
     // Assuming data is the original filename.
     var ms = new MemoryStream(data);
     var image = Image.FromStream(ms);
     image.Save(filename);
     ResizeImage(image, 800, 600, "large.jpg");
     ResizeImage(image, 480, 320, "medium.jpg");
     ResizeImage(image, 192, 144, "small.jpg");
  }

  private void ResizeImage(Image image, int width, int height, string filename)
  {
     using (var newImage = new Bitmap(width, height))
     {
        var graphics = Graphics.FromImage(newImage);
        graphics.DrawImage(image, 0, 0, width, height);
        newImage.Save(filename, ImageFormat.Jpeg);
     }
  }

Answer 4

For intensive server-side code, I suggest you use other techniques than GDI+ that has not been designed to handle images chunk by chunk (in a streaming manner).

You can use Windows Imaging Component or WPF for this task. There is a very good example on how to do this in a fast and - more important - scalable manner here:

The fastest way to resize images from ASP.NET. And it’s (more) supported-ish.

Answer 5

See my answer here Create thumbnail image

There is a function on Image which returns a thumbnail like this:

Image image = Image.FromFile(fileName);
Image thumb = image.GetThumbnailImage(120, 120, ()=>false, IntPtr.Zero);
thumb.Save(Path.ChangeExtension(fileName, "thumb"));

Answer 6

This has done me fine for years:

public static void CreateThumbnail(string filename, int desiredWidth, int desiredHeight, string outFilename)
{
    using (System.Drawing.Image img = System.Drawing.Image.FromFile(filename))
    {
        float widthRatio = (float)img.Width / (float)desiredWidth;
        float heightRatio = (float)img.Height / (float)desiredHeight;
        // Resize to the greatest ratio
        float ratio = heightRatio > widthRatio ? heightRatio : widthRatio;
        int newWidth = Convert.ToInt32(Math.Floor((float)img.Width / ratio));
        int newHeight = Convert.ToInt32(Math.Floor((float)img.Height / ratio));
        using (System.Drawing.Image thumb = img.GetThumbnailImage(newWidth, newHeight, new System.Drawing.Image.GetThumbnailImageAbort(ThumbnailImageAbortCallback), IntPtr.Zero))
        {
            thumb.Save(outFilename, System.Drawing.Imaging.ImageFormat.Jpeg);
        }
    }
}

public static bool ThumbnailImageAbortCallback()
{
    return true;
}