Best way to stamp an image with another image to create a watermark in ASP.NET?

Question

Anyone know? Want to be able to on the fly stamp an image with another image as a watermark, also to do large batches. Any type of existing library or a technique you know of would be great.

Answer 1

This will answer your question:

http://www.codeproject.com/KB/GDI-plus/watermark.aspx

Good luck!

Answer 2

I have had good luck with ImageMagick. It has an API for .NET too.

Answer 3

here is my full article: http://forums.asp.net/p/1323176/2634923.aspx

use the SDK Command Prompt and navigate the active folder to the folder containing the below source code... then compile the code using

vbc.exe watermark.vb /t:exe /out:watermark.exe

this will create an exe in the folder.. the exe accepts two parameters: ex.

watermark.exe "c:\source folder" "c:\destination folder"

this will iterate through the parent folder and all subfolders. all found jpegs will be watermarked with the image you specify in the code and copied to the destination folder. The original image will stay untouched.

// watermark.vb --

Imports System
Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports System.Drawing.Imaging
Imports System.IO

Namespace WatermarkManager
    Class Watermark
        Shared sourceDirectory As String = "", destinationDirectory As String = ""

        Overloads Shared Sub Main(ByVal args() As String)

            'See if an argument was passed from the command line
            If args.Length = 2 Then
                sourceDirectory = args(0)
                destinationDirectory = args(1)

                ' make sure sourceFolder is legit
                If Directory.Exists(sourceDirectory) = False
                    TerminateExe("Invalid source folder. Folder does not exist.")
                    Exit Sub
                End If

                ' try and create destination folder
                Try
                    Directory.CreateDirectory(destinationDirectory)
                Catch
                    TerminateExe("Error creating destination folder. Invalid path cannot be created.")
                    Exit Sub
                End Try

                ' start the magic
                CreateHierarchy(sourceDirectory,destinationDirectory)

            ElseIf args.Length = 1
                If args(0) = "/?"
                    DisplayHelp()
                Else
                    TerminateExe("expected: watermark.exe [source path] [destination path]")
                End If
                Exit Sub
            Else
                TerminateExe("expected: watermark.exe [source path] [destination path]")
                Exit Sub
            End If

            TerminateExe()
        End Sub

        Shared Sub CreateHierarchy(ByVal sourceDirectory As String, ByVal destinationDirectory As String)

            Dim tmpSourceDirectory As String = sourceDirectory

            ' copy directory hierarchy to destination folder
            For Each Item As String In Directory.GetDirectories(sourceDirectory)
                Directory.CreateDirectory(destinationDirectory + Item.SubString(Item.LastIndexOf("\")))

                If hasSubDirectories(Item)
                    CreateSubDirectories(Item)
                End If
            Next

            ' reset destinationDirectory
            destinationDirectory = tmpSourceDirectory

            ' now that folder structure is set up, let's iterate through files
            For Each Item As String In Directory.GetDirectories(sourceDirectory)
                SearchDirectory(Item)
            Next
        End Sub

        Shared Function hasSubDirectories(ByVal path As String) As Boolean
            Dim subdirs() As String = Directory.GetDirectories(path)
            If subdirs.Length > 0
                Return True
            End If
            Return False
        End Function

        Shared Sub CheckFiles(ByVal path As String)
            For Each f As String In Directory.GetFiles(path)
                If f.SubString(f.Length-3).ToLower = "jpg"
                    WatermarkImage(f)
                End If
            Next
        End Sub

        Shared Sub WatermarkImage(ByVal f As String)

            Dim img As System.Drawing.Image = System.Drawing.Image.FromFile(f)
            Dim graphic As Graphics
            Dim indexedImage As New Bitmap(img)
            graphic = Graphics.FromImage(indexedImage)
            graphic.DrawImage(img, 0, 0, img.Width, img.Height)
            img = indexedImage

            graphic.SmoothingMode = SmoothingMode.AntiAlias
            graphic.InterpolationMode = InterpolationMode.HighQualityBicubic

            Dim x As Integer, y As Integer
            Dim source As New Bitmap("c:\watermark.png")
            Dim logo As New Bitmap(source, CInt(img.Width / 3), CInt(img.Width / 3))
            source.Dispose()
            x = img.Width - logo.Width
            y = img.Height - logo.Height
            graphic.DrawImage(logo, New Point(x,y))
            logo.Dispose()

            img.Save(destinationDirectory+f.SubString(f.LastIndexOf("\")), ImageFormat.Jpeg)
            indexedImage.Dispose()
            img.Dispose()
            graphic.Dispose()

            Console.WriteLine("successfully watermarked " + f.SubString(f.LastIndexOf("\")+1))
            Console.WriteLine("saved to: " + vbCrLf + destinationDirectory + vbCrLf)

        End Sub

        Shared Sub SearchDirectory(ByVal path As String)
            destinationDirectory = destinationDirectory + path.SubString(path.LastIndexOf("\"))
            CheckFiles(path)
            For Each Item As String In Directory.GetDirectories(path)
                destinationDirectory += Item.SubString(Item.LastIndexOf("\"))

                CheckFiles(Item)

                If hasSubDirectories(Item)
                    destinationDirectory = destinationDirectory.SubString(0,destinationDirectory.LastIndexOf("\"))
                    SearchDirectory(Item)
                    destinationDirectory += Item.SubString(Item.LastIndexOf("\"))
                End If
                destinationDirectory = destinationDirectory.SubString(0,destinationDirectory.LastIndexOf("\"))
            Next
            destinationDirectory = destinationDirectory.SubString(0,destinationDirectory.LastIndexOf("\"))
        End Sub

        Shared Sub CreateSubDirectories(ByVal path As String)
            destinationDirectory = destinationDirectory + path.SubString(path.LastIndexOf("\"))
            For Each Item As String In Directory.GetDirectories(path)
                destinationDirectory += Item.SubString(Item.LastIndexOf("\"))
                Directory.CreateDirectory(destinationDirectory)
                Console.WriteLine(vbCrlf + "created: " + vbCrlf + destinationDirectory)

                If hasSubDirectories(Item)
                    destinationDirectory = destinationDirectory.SubString(0,destinationDirectory.LastIndexOf("\"))
                    CreateSubDirectories(Item)
                    destinationDirectory += Item.SubString(Item.LastIndexOf("\"))
                End If
                destinationDirectory = destinationDirectory.SubString(0,destinationDirectory.LastIndexOf("\"))
            Next
            destinationDirectory = destinationDirectory.SubString(0,destinationDirectory.LastIndexOf("\"))
        End Sub

        Shared Sub TerminateExe(ByVal Optional msg As String = "")
            If msg  ""
                Console.WriteLine(vbCrLf + "AN ERROR HAS OCCURRED //" + vbCrLf + msg)
            End If
            Console.WriteLine(vbCrLf + "Press [enter] to close...")
            'Console.Read()
        End Sub

        Shared Sub DisplayHelp()
            Console.WriteLine("watermark.exe accepts two parameters:" + vbCrLf + " - [source folder]")
            Console.WriteLine(" - [destination folder]")
            Console.WriteLine("ex." + vbCrLf + "watermark.exe ""c:\web_projects\dclr source"" ""d:\new_dclr\copy1 dest""")
            Console.WriteLine(vbCrLf + "Press [enter] to close...")
            Console.Read()
        End Sub
    End Class
End Namespace