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Posted 25 Nov 2008

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Image resizing with asp.net

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25 Nov 2008CPOL
Resizing the very large size images with help of asp.net and vb.net


ResizeImages.JPG

 

Introduction  

Sometime when we are uploading images and if we resize with applying variable size then images are not displayed in good quality. So, this article show how to resize images without scratch the image.

Background 

In this article we have to use some drawing methods.
 

Using the code 

VB.NET
' Create new stream.
' Dim stream As New FileStream(fileName, FileMode.Open, FileAccess.Read)

' Create new image.
Dim image As System.Drawing.Image = System.Drawing.Image.FromStream(Stream)

' Calculate proportional max width and height.
Dim oldWidth As Integer = image.Width
Dim oldHeight As Integer = image.Height
If (CDec(oldWidth) / CDec(oldHeight)) > (CDec(newWidth) / CDec(newHeight)) Then
    Dim ratio As Decimal = CDec(newWidth) / oldWidth
    newHeight = CInt((oldHeight * ratio))
Else
    Dim ratio As Decimal = CDec(newHeight) / oldHeight
    newWidth = CInt((oldWidth * ratio))
End If

' Create a new bitmap with the same resolution as the original image.
Dim bitmap As New Bitmap(newWidth, newHeight, PixelFormat.Format24bppRgb)
bitmap.SetResolution(image.HorizontalResolution, image.VerticalResolution)

' Create a new graphic.
Dim graphics__1 As Graphics = Graphics.FromImage(bitmap)
graphics__1.Clear(Color.White)
graphics__1.InterpolationMode = InterpolationMode.HighQualityBicubic

' Create a scaled image based on the original.
graphics__1.DrawImage(image, New Rectangle(0, 0, newWidth, newHeight),
                      New Rectangle(0, 0, oldWidth, oldHeight), GraphicsUnit.Pixel)
                      graphics__1.Dispose()

 ' Save the scaled image.
 bitmap.Save(Server.MapPath("Images/") & strDestinationFileName, image.RawFormat)

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


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Comments and Discussions

 
QuestionSee imageresizing.net instead Pin
Nathanael Jones6-Jan-12 6:37
MemberNathanael Jones6-Jan-12 6:37 
GeneralMy vote of 1 Pin
aa.azizkhani25-Nov-08 19:45
Memberaa.azizkhani25-Nov-08 19:45 
GeneralMy vote of 1 Pin
JLuterek25-Nov-08 5:23
MemberJLuterek25-Nov-08 5:23 
GeneralMy vote of 1 Pin
Ramon Smits25-Nov-08 4:04
MemberRamon Smits25-Nov-08 4:04 
GeneralCaching Pin
Ramon Smits25-Nov-08 4:03
MemberRamon Smits25-Nov-08 4:03 
GeneralBad code Pin
Ramon Smits25-Nov-08 4:02
MemberRamon Smits25-Nov-08 4:02 

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