(2005) How can I draw a string on a picture file?

[javad2000]

Hello

How is it possible to write a string on a picture file? Ex:

I want to write:
"This is a test"

on:
C:\Test.bmp

and save it as:
C:\Test1.bmp

Thank you

[Ken B]

Check out:

http://www.codeproject.com/vb/net/Tr...eWatermark.asp

[javad2000]

Check out:

http://www.codeproject.com/vb/net/Tr...eWatermark.asp

Thank you very much Ken B
The solution was quite ez and user-friendly.

Here's the code

Sub DrawOnPicture(ByVal StrInputFilePath As String, ByVal StrOutputFilePath As String, ByVal StrWaterMark As String)
        'Construct a Bitmap object from a jpg's filename:
        Dim bmp As Bitmap = New Bitmap(StrInputFilePath)
        'Obtain a Graphics object from & for that Bitmap:
        Dim canvas As Graphics = Graphics.FromImage(bmp)
        'Draw the watermark string onto the Bitmap:
        canvas.DrawString(strWatermark, _
        New Font("Verdana", 14, FontStyle.Bold), _
        New SolidBrush(Color.Beige), 0, 0)
        'Save the watermarked bitmap to a new file:
        bmp.Save(StrOutputFilePath)
    End Sub

I have only 1 more problem.
How can I know the Height and Width of the "String" and also the Height and width of the "Picture" (in pixels)?

('cause I want to draw the string on the right side of the pic)

Thank you

[Ken B]

I started to work on this 6 months ago and got side tracked. Looking at my code, I found that you will have a problem writing text on a Format8bppIndexed image.

I have attached an image in the above format. Try your existing code on it and see if it works.

The following code will tell you if an image is a Format8bppIndexed image.

  Public Structure imageInformation

    Dim Caption As String
    Dim FileExist As Boolean
    Dim FileName As String
    Dim Height As Single
    Dim HorizontalResolution As Single
    Dim ImageType As String
    Dim Length As Double
    Dim Name As String
    Dim Palette As Single
    Dim PixelFormat As String
    Dim Postion As Int16
    Dim PrimaryImage As Boolean
    Dim ResizeHeight As Single
    Dim ResizePercentage As Single
    Dim ResizeWidth As Single
    Dim SaveAsFileName As String
    Dim UpdatedAt As String
    Dim ValidImage As Boolean
    Dim VerticalResolution As Single
    Dim Width As Single

  End Structure

  Public Sub getImageFileInfo(ByVal fileName As String, ByRef tmpImage As imageInformation)

    If Not System.IO.File.Exists(fileName) Then
      tmpImage.ValidImage = False
      Exit Sub
    End If

    Try
      Dim bit As New Bitmap(fileName)
      tmpImage.FileExist = True
      tmpImage.FileName = fileName
      tmpImage.Height = bit.Height
      tmpImage.HorizontalResolution = bit.HorizontalResolution
      tmpImage.Length = FileLen(fileName)
      tmpImage.PixelFormat = bit.PixelFormat.ToString
      tmpImage.ImageType = bit.GetType.ToString
      tmpImage.ValidImage = True
      tmpImage.VerticalResolution = bit.VerticalResolution
      tmpImage.Width = bit.Width
      bit.Dispose()
    Catch ex As Exception
      tmpImage.FileName = fileName
      tmpImage.ValidImage = False
      Call displayMessage("Exception in getImageFileInfo." & Environment.NewLine & Environment.NewLine & "Error: " & ex.Message, MessageBoxButtons.OK, MessageBoxIcon.Error)
    End Try

  End Sub

If it is, all you have to do is recreate it as a 24bit image using the following:

    Dim orginalImage As New Bitmap(ImageFileName)
    Try
      If System.IO.File.Exists(NewImageFileName) Then
        System.IO.File.Delete(NewImageFileName)
      End If
      orginalImage.SetResolution(NewResolution, NewResolution)
      orginalImage.Save(NewImageFileName, System.Drawing.Imaging.ImageFormat.Jpeg)
      orginalImage.Dispose()

    Catch exIO As System.IO.IOException
      MessageBox.Show("IOException in reCreateImage." & Environment.NewLine & Environment.NewLine & exIO.Message, "vbPDF Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
      Return False

    Catch ex As Exception
      MessageBox.Show("Exception in reCreateImage." & Environment.NewLine & Environment.NewLine & ex.Message, "vbPDF Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
      Return False

    Finally
      orginalImage.Dispose()

    End Try

The above code is from two different appliactions, but they should work.

I can't help you with your size question at the momment, but will look into it later today.

Ken

[javad2000]

You are right.
It said that the picture has an indexed pixel and cannot be converted to a graphics object.

Thank you