An easy way to resize an image keepeing with the best resulation quality.

• Download ImageResize - 60.74 KB

Introduction

This article will show you on how to resize an image keepeing the best resulation quality.

Background

This is a most common fearutes to add image / signature in any web/windows application. In my project I need to give an interface where the user upload there images and the system has the ability to resizd the image accordingly.

Using the code

Most of the time developers face to resize an uploded images runtime. In this article I try to resize an image runtime with keeping the best quality, for this purpose I use the fetures of .Net framework 3.5 like (System.Drawing, IO). The sample code is given below:

  Public Function ImageResize(ByVal strImageSrcPath As String, ByVal strImageDesPath As String, Optional ByVal intWidth As Integer = 0, Optional ByVal intHeight As Integer = 0) As String

        If System.IO.File.Exists(strImageSrcPath) = False Then Return "Err."

        Dim objImage As System.Drawing.Image = System.Drawing.Image.FromFile(strImageSrcPath)

        If intWidth > objImage.Width Then intWidth = objImage.Width
        If intHeight > objImage.Height Then intHeight = objImage.Height
        If intWidth = 0 And intHeight = 0 Then
            intWidth = objImage.Width
            intHeight = objImage.Height
        ElseIf intHeight = 0 And intWidth <> 0 Then
            intHeight = Fix(objImage.Height * intWidth / objImage.Width)
        ElseIf intWidth = 0 And intHeight <> 0 Then
            intWidth = Fix(objImage.Width * intHeight / objImage.Height)
        End If

        Dim imgOutput As New Bitmap(objImage, intWidth, intHeight)
        Dim imgFormat = objImage.RawFormat

        objImage.Dispose()
        objImage = Nothing

        If strImageSrcPath = strImageDesPath Then System.IO.File.Delete(strImageSrcPath)
        ' send the resized image to the viewer
        imgOutput.Save(strImageDesPath, imgFormat)
        imgOutput.Dispose()

        Return strImageDesPath

    End Function
		

Function Detail: Fix : Return the integer portion of a number. FromFile:Creates an System.Drawing.Image from the specified file. Input Valus # A string that contains the name of the file from which to create the System.Drawing.Image. Return Values # The System.Drawing.Image this method creates.