Resizing image proportionally in ASP.NET C# by specifying either Height or Width

Question

I need a code that will allow me to resize images, but with the following functionality:

1) resize image upon upload

2) Resize image proportionally by specifying

Answer 1

Although it seems like you should be able to copy and paste a snippet to do this, there are a ton of pitfalls you need to look out for if you're building your own image resizing system. It's better to use a proven, tested, and supported open-source library.

To resize to a file directly from HttpPostedFile, call

ImageBuilder.Current.Build(httpPostedFile, "img.jpg", new ResizeSettings("width=200&quality=90"));

To resize an existing file, call

ImageBuilder.Current.Build("orig.jpg", "img.jpg", new ResizeSettings("width=200&quality=90"));

The ImageResizing.Net library is free, and MIT-licensed (no worries about licensing problems).

Answer 2

This is how is did in my project

On Button click while uploading file:

System.Drawing.Bitmap bmpPostedImage = new System.Drawing.Bitmap(File1.PostedFile.InputStream);
     System.Drawing.Image objImage = ScaleImage(bmpPostedImage, 81);
     objImage.Save(SaveLocation,ImageFormat.Png);
     lblmsg.Text = "The file has been uploaded.";

---

public static System.Drawing.Image ScaleImage(System.Drawing.Image image, int maxHeight)
        {
            var ratio = (double)maxHeight / image.Height;

            var newWidth = (int)(image.Width * ratio);
            var newHeight = (int)(image.Height * ratio);

            var newImage = new Bitmap(newWidth, newHeight);
            using (var g = Graphics.FromImage(newImage))
            {
                g.DrawImage(image, 0, 0, newWidth, newHeight);
            }
            return newImage;
        }

More Detail Click here

https://codepedia.info/how-to-resize-image-while-uploading-in-asp-net-using-c/

Answer 3

Last day I found imageresizer and its great. and good API. Works Great. Downloaded from Visual studio 2010 Extension Manager: http://nuget.org/.

Easy Steps to download API in VS-2010:

1). Install Extension http://nuget.org/.



3). Find and Install ImageResizing

4).Then Code: (I m using here cropping. you can use any) Documentation on imageresizing.net

string uploadFolder = Server.MapPath(Request.ApplicationPath + "images/");
FileUpload1.SaveAs(uploadFolder + FileUpload1.FileName);


//The resizing settings can specify any of 30 commands.. See http://imageresizing.net for details.
ResizeSettings resizeCropSettings = new ResizeSettings("width=200&height=200&format=jpg&crop=auto");

//Generate a filename (GUIDs are safest).
string fileName = Path.Combine(uploadFolder, System.Guid.NewGuid().ToString());

//Let the image builder add the correct extension based on the output file type (which may differ).
fileName = ImageBuilder.Current.Build(uploadFolder + FileUpload1.FileName, fileName, resizeCropSettings, false, true);

Try!!! its very awsumm and easy to use. thanks.

Answer 4

Taken from this Stackoverflow answer, I come up with:

public static Image Resize(this Image image, int maxWidth = 0, int maxHeight = 0)
    {
        if (maxWidth == 0)
            maxWidth = image.Width;
        if (maxHeight == 0)
            maxHeight = image.Height;

        var ratioX = (double)maxWidth / image.Width;
        var ratioY = (double)maxHeight / image.Height;
        var ratio = Math.Min(ratioX, ratioY);

        var newWidth = (int)(image.Width * ratio);
        var newHeight = (int)(image.Height * ratio);

        var newImage = new Bitmap(newWidth, newHeight);
        Graphics.FromImage(newImage).DrawImage(image, 0, 0, newWidth, newHeight);
        return newImage;
    }

To resize Image specifying its maxWidth:

var _image = Image.FromStream(Source);
var _thumbImage = _image.Resize(100);

To resize Image specifying its maxHeight:

var _image = Image.FromStream(Source);
var _thumbImage = _image.Resize(maxHeight: 100);

Answer 5

Code I use for image resizing: http://sietch.net/ViewNewsItem.aspx?NewsItemID=105