Question

Possible Duplicate:
How to generate square thumbnail of an image?

I’m trying to save my image as thumbnail. How can I do this ?

Here is my action control:

[HttpPost]
[ValidateInput(false)]
public ActionResult banner_create(banner banner, HttpPostedFileBase file)
{
    var fileName = Path.GetFileName(file.FileName);
    var path = Path.Combine(Server.MapPath("~/banner_image/"), fileName);
    var extension = Path.GetExtension(path);
    file.SaveAs(path);
    banner.banner_image_description = extension;
    banner.banner_image_name = fileName;
    if (ModelState.IsValid)
    {
        db.banner.AddObject(banner);
        db.SaveChanges();
        return RedirectToAction("index");
    }

    return View(banner);
}

Answer 1

The following code should work fine.
I’ve added some comments, so you can see what’s going on.

// First, we convert an HttpPostedFileBase to an Image
// (Please note that you need to reference System.Drawing.dll)
using (var image = Image.FromStream(httpPostedFileBase.InputStream, true, true))
{
    // Then we create a thumbnail.
    // The simplest way is using Image.GetThumbnailImage:
    using (var thumb = image.GetThumbnailImage(
        thumbWidth,
        thumbHeight,
        () => false,
        IntPtr.Zero))
    {
        // Finally, we encode and save the thumbnail.
        var jpgInfo = ImageCodecInfo.GetImageEncoders()
            .Where(codecInfo => codecInfo.MimeType == "image/jpeg").First();

        using (var encParams = new EncoderParameters(1))
        {
            // Your output path
            string outputPath = "...";
            // Image quality (should be in the range [0..100])
            long quality = 90;
            encParams.Param[0] = new EncoderParameter(Encoder.Quality, quality);
            thumb.Save(outputPath, jpgInfo, encParams);
        }
    }
}