resized image doesn't save

Question

User1280950372 posted

The image resizes fine in the following code but it doesn't save. Instead, the original-sized image is loaded back in the browser. Any suggestions?

    Dim txt As TextBox
    Dim lbl As Label
    Dim rbl As RadioButtonList
    Dim chk As CheckBox
    Dim ddl As DropDownList
    Dim ful As FileUpload
    Dim lnk As HyperLink

    Public Function ImageResize(ByVal strSrc As String, ByVal strDest As String) As String
        Dim objImage As Image = Image.FromFile(strSrc)
        Dim dblNewHgt, dblNewWidth, dblFactor As Double
        Dim dblOldHgt As Double = objImage.Height
        Dim dblOldWidth As Double = objImage.Width
        Dim imgOutput As New Bitmap(objImage, dblNewWidth, dblNewHgt)
        Dim imgFormat = objImage.RawFormat

        If dblOldHgt > 300 Then dblFactor = 300 / dblOldHgt
        If dblFactor = 0 Then
            If dblOldWidth > 300 Then dblFactor = 300 / dblOldWidth
        End If
        'compare dimensions then, depending on size, set factor for adjustment of width and height
        dblNewHgt = dblOldHgt
        dblNewWidth = dblOldWidth
        If dblFactor > 0 Then
            dblNewHgt *= dblFactor
            dblNewWidth *= dblFactor
        End If
        Do While dblNewHgt > 300 Or dblNewWidth > 300
            dblNewHgt *= 0.9
            dblNewWidth *= 0.9
        Loop

        objImage.Dispose()
        objImage = Nothing

        ' send the resized image to the viewer
        imgOutput.Save(strDest, imgFormat)
        imgOutput.Dispose()

        Return strDest

    End Function

 

Answer 1

User-232462845 posted

D Hi

I think you have to create agraphic and re-draw the image before saving.
See the code below.i have been using it fo a long.. Original version was collected from a web article..(thanks to the author)

Non-relevant lines are commnted out

(Hi, I forgot to mention one thing.. You have to import Namespace System.Drawing <%@ import Namespace="System.Drawing" %>) 

 

 

Sub resizeimage()
        Const Lx As Integer = 100 ' max width for thumbnails
        Const Ly As Integer = 140  ' max height for thumbnails
        Const upload_dir As String = "Some path\images\"   ' directory to upload file
        'Const upload_original = "sample"    ' filename to save original as (suffix added by script)
        'Const upload_thumb = "thumb"    ' filename to save thumbnail as (suffix added by script)
        Const upload_max_size As Integer = 50 ' max size of the upload (KB) note: this doesn't override any server upload limits
        Dim fileExt As String ' used to store the file extension (saves finding it mulitple times)
        Dim newWidth, newHeight As Integer ' new width/height for the thumbnail
        Dim l2 As Integer ' temp variable used when calculating new size
        'Dim fileFld As HttpPostedFile   ' used to grab the file upload from the form
        Dim originalimg As System.Drawing.Image ' used to hold the original image
        Dim msg As String ' display results
        
        'FileFld is the ID of fileupload control
        fileExt = System.IO.Path.GetExtension(FileFld.FileName.ToLower())
        If Not fileExt = ".jpg" Then
            'Label6.Text = "File format not supported!"
            'Label6.ForeColor = Color.FromName("Red")
            'lblMsg.ForeColor = Color.FromName("Red")
            'lblMsg.Text = "SORRY...You can upload only jpg files."
            'Button1.Visible = False
            Exit Sub
        End If
        
        If FileFld.FileContent.Length > upload_max_size * 1024 Then
            'Label6.Text = "File toolarge!"
            'Label6.ForeColor = Color.FromName("Red")
            'lblMsg.ForeColor = Color.FromName("Black")
            'lblMsg.Text = "SORRY...maximum upload size permited is 50KB!!."
            'Button1.Visible = False
            Exit Sub
        End If
        originalimg = System.Drawing.Image.FromStream(FileFld.FileContent)
        
        If (originalimg.Width / Lx) > (originalimg.Height / Ly) Then
            l2 = originalimg.Width
            newWidth = Lx
            newHeight = originalimg.Height * (Lx / l2)
            If newHeight > Ly Then
                newWidth = newWidth * (Ly / newHeight)
                newHeight = Ly
            End If
        Else
            l2 = originalimg.Height
            newHeight = Ly
            newWidth = originalimg.Width * (Ly / l2)
            If newWidth > Lx Then
                newHeight = newHeight * (Lx / newWidth)
                newWidth = Lx
            End If
        End If

        Dim thumb As New Bitmap(newWidth, newHeight)
        'Create a graphics object   
        thumb = originalimg.GetThumbnailImage(newWidth, newHeight, Nothing, IntPtr.Zero)
        Dim gr_dest As Graphics = Graphics.FromImage(thumb)
        'Re-draw the image to the specified height and width
        gr_dest.DrawImage(originalimg, 0, 0, thumb.Width, thumb.Height)
        ' originalimg.Save(Server.MapPath(upload_dir & upload_original & fileExt), originalimg.RawFormat)
        thumb.Save(upload_dir & "Somename" & fileExt, originalimg.RawFormat)
        ' msg = "Uploaded " & FileFld.FileName & " to " & upload_dir & "id" & HisId & fileExt
    End Sub

 

Answer 2

User1280950372 posted

 Thanks, but I'm still getting the GDI+ error (I think that's what it's called).

Answer 3

User1280950372 posted

I'd like to go back to my original code and make changes from there. I'm getting an error on line 14 that reads "Parameter is not valid." I imagine it has to do with the objImage parameter but I don't know what to do about it.

Answer 4

User1280950372 posted

<BUMP> Hey, folks, I still need help. Don't abandon me! Surely there's someone with expertise on problems such as this?

Answer 5

User-232462845 posted

Hi,

Don’t feel that You are abandoned..Nobody is abandoned here..

Here is the working example. It Resizes and saves the thumbnail in the application folder. and the resized image is displayed in the image control. Only change needed in the code is ..Don’t forget to change the ImageUrl value of the Image Control- Image1.

This will resize the uploaded image without loosing the aspect ratio with maximum width = 100px and maximum height = 140px (You can change these values as you like)

As it is only a trial, this example overwrites the image every time. We can save it with unique filenames also.

Try and respond.

Cheers

basheerkal

Code for Reziser.aspx page:

 

<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Reziser.aspx.vb" Inherits="www_test1_Reziser" %>
<%@ Import Namespace= "System.Drawing" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
    <style type="text/css">

        .style34
        {
            font-size: x-small;
        }
        .style36
        {
            font-family: Arial, Helvetica, sans-serif;
        }
    </style>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    
        <asp:Label ID="lblMsg" runat="server" Font-Bold="True" Width="810px" 
                    Font-Names="Arial" Font-Size="10pt" ForeColor="Red" Height="16px"></asp:Label>
        <br />
        <br />
                
        <asp:Image ID="Image1" runat="server" ImageUrl="~/www/test1/TestThumb.jpg" />
                
        <br />
        <span 
                        class="style34"><span 
                        class="style36">
        <asp:FileUpload ID="FileFld" runat="server" 
                        BackColor="#CFD150" />
                       
                    <asp:RequiredFieldValidator ID="RequiredFieldValidator1" 
            runat="server" ControlToValidate="FileFld" 
                        ErrorMessage="File not selected" Font-Names="Arial" 
            Font-Size="Small">
                    </asp:RequiredFieldValidator>
        <br />
        <br />
        <br />
                    <asp:Button ID="Button2" runat="server" OnClick="Button2_Click" 
                        Text="Change Photo" />
                       
            <asp:Label ID="Label6" runat="server" Font-Bold="True" 
                    Width="437px" Font-Names="Arial" Font-Size="12pt" ForeColor="Red" 
                    Height="20px" BorderStyle="None" Font-Underline="True"></asp:Label>
                     <asp:Button ID="Button1" runat="server" Text="Go back" 
                    PostBackUrl="cph.aspx" Visible="False" CausesValidation="False" />
                    </span>
        </span>
    
    </div>
    <p>
         </p>
    </form>
</body>
</html>

 

 

Code for resizer.aspx.vb

 

Imports System.Drawing
Partial Class www_test1_Reziser
    Inherits System.Web.UI.Page
    Const Lx As Integer = 100  ' max width for thumbnails
    Const Ly As Integer = 140  ' max height for thumbnails   
    Const upload_max_size As Integer = 150 ' max size of the upload (KB) note: this doesn't override any server upload limits
    Public fileExt As String ' used to store the file extension (saves finding it mulitple times)
    Dim newWidth, newHeight As Integer ' new width/height for the thumbnail
    Dim L2 As Single  ' temp variable used when calculating new size
    Dim OriginalImg As System.Drawing.Image ' used to hold the original image
    Dim Msg As String ' display results


    Sub RessizeImage()
        fileExt = System.IO.Path.GetExtension(FileFld.FileName.ToLower())

        If Not fileExt = ".jpg" Then
            Label6.Text = "File format not supported!"
            Label6.ForeColor = Color.FromName("Red")
            lblMsg.ForeColor = Color.FromName("Red")
            lblMsg.Text = "SORRY...You can upload only jpg files."
            Button1.Visible = False
            Exit Sub
        End If

        If FileFld.FileContent.Length > upload_max_size * 1024 Then
            Label6.Text = "File toolarge!"
            Label6.ForeColor = Color.FromName("Red")
            lblMsg.ForeColor = Color.FromName("Black")
            lblMsg.Text = "SORRY...maximum upload size permited is " & upload_max_size & "KB!."
            Button1.Visible = False
            Exit Sub
        End If
        OriginalImg = System.Drawing.Image.FromStream(FileFld.FileContent)

        If (OriginalImg.Width / Lx) > (OriginalImg.Height / Ly) Then
            L2 = OriginalImg.Width
            newWidth = Lx
            newHeight = OriginalImg.Height * (Lx / L2)
            If newHeight > Ly Then
                newWidth = newWidth * (Ly / newHeight)
                newHeight = Ly
            End If
        Else
            L2 = OriginalImg.Height
            newHeight = Ly
            newWidth = OriginalImg.Width * (Ly / L2)
            If newWidth > Lx Then
                newHeight = newHeight * (Lx / newWidth)
                newWidth = Lx
            End If
        End If

        Dim thumb As New Bitmap(newWidth, newHeight)
        'Create a graphics object   
        thumb = OriginalImg.GetThumbnailImage(newWidth, newHeight, Nothing, IntPtr.Zero)
        Dim gr_dest As Graphics = Graphics.FromImage(thumb)
        'Re-draw the image to the specified height and width
        gr_dest.DrawImage(OriginalImg, 0, 0, thumb.Width, thumb.Height)
        ' originalimg.Save(Server.MapPath(upload_dir & upload_original & fileExt), originalimg.RawFormat)
        thumb.Save(Server.MapPath("TestThumb.jpg"), OriginalImg.RawFormat)
        Msg = "Uploaded " & FileFld.FileName & " to " & Server.MapPath("TestThumb.jpg")
        lblMsg.Text = Msg

    End Sub

    Protected Sub Button2_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button2.Click
        RessizeImage()
    End Sub

End Class

 

 

 

 

 

Answer 6

User1280950372 posted

Thanks, your code worked, for the most part. It sizes and displays images correctly, with the exception of one image, which turns out all black. Can't figure that one out.

Answer 7

User-232462845 posted

Hi,

Happy that it worked for you.

Which image turned out Black. What was it's original resolution. Is it a GIF?

basherkal