Aspose, how to measure a Font?

Question

I'm using the Aspose Imaging library and my intention is to insert a centered watermark into an image, the library provides a custom Font class.

How I can measure the Width and Height of this kind of Font to center the text in the image?

What I've tried:

Dim font As New Aspose.Imaging.Font("Times New Roman", 64, FontStyle.Bold)

TextRenderer.MeasureText("Hello World!", TryCast(font, System.Drawing.Font)

I would like to know if exist a "direct" way to measure the text of a Aspose.Imaging.Font instead of creating a secondary System.Drawing.Font to measure it.

Answer 1

A solution written by me:

''' <summary>
''' Adds a watermark into an image, at the specified position.
''' </summary>
''' <param name="img">Indicates the image.</param>
''' <param name="text">Indicates the watermark text.</param>
''' <param name="fnt">Indicates the watermark text font.</param>
''' <param name="color">Indicates the watermark text color.</param>
''' <param name="position">Indicates the watermark text position.</param>
''' <returns>Aspose.Imaging.Image.</returns>
Private Function AddWatermark(ByVal img As Aspose.Imaging.Image,
                              ByVal text As String,
                              ByVal fnt As Aspose.Imaging.Font,
                              ByVal color As Aspose.Imaging.Color,
                              ByVal position As Aspose.Imaging.PointF) As Aspose.Imaging.Image

    Using brush As New Aspose.Imaging.Brushes.SolidBrush With {.Color = color, .Opacity = 100.0F}

        ' Create and initialize an instance of Graphics class.
        Dim g As New Aspose.Imaging.Graphics(img)

        ' Draw a String using the SolidBrush object and Font, at specific Point and with specific format.
        g.DrawString(s:=text, font:=fnt, brush:=brush, point:=position)

    End Using

    ' Return the modified image.
    Return img

End Function

''' <summary>
''' Adds a watermark into an imag, at a prefedined position.
''' </summary>
''' <param name="img">Indicates the image.</param>
''' <param name="text">Indicates the watermark text.</param>
''' <param name="fnt">Indicates the watermark text font.</param>
''' <param name="color">Indicates the watermark text color.</param>
''' <param name="position">Indicates the watermark text position.</param>
''' <param name="verticalmargin">Indicates the watermark text vertical margin.</param>
''' <param name="horizontalmargin">Indicates the watermark text horizontal margin.</param>
''' <returns>Aspose.Imaging.Image.</returns>
Private Function AddWatermark(ByVal img As Aspose.Imaging.Image,
                              ByVal text As String,
                              ByVal fnt As Aspose.Imaging.Font,
                              ByVal color As Aspose.Imaging.Color,
                              ByVal position As WatermarkPosition,
                              Optional ByVal verticalmargin As Single = 0.0F,
                              Optional ByVal horizontalmargin As Single = 0.0F) As Aspose.Imaging.Image

    Dim textformat As New Aspose.Imaging.StringFormat
    Dim textposition As Aspose.Imaging.PointF = Aspose.Imaging.PointF.Empty

    Select Case position

        Case WatermarkPosition.Top ' Note: horizontalmargin value is ignored.
            textposition = New Aspose.Imaging.PointF(x:=(img.Width \ 2), y:=verticalmargin)
            textformat.Alignment = Aspose.Imaging.StringAlignment.Center
            textformat.FormatFlags = Aspose.Imaging.StringFormatFlags.MeasureTrailingSpaces

        Case WatermarkPosition.TopLeft
            textposition = New Aspose.Imaging.PointF(x:=horizontalmargin, y:=verticalmargin)
            textformat.Alignment = Aspose.Imaging.StringAlignment.Near
            textformat.FormatFlags = Aspose.Imaging.StringFormatFlags.MeasureTrailingSpaces

        Case WatermarkPosition.TopRight
            Dim f As New System.Drawing.Font(fnt.Name, fnt.Size, DirectCast(fnt.Style, System.Drawing.FontStyle))
            Dim measure As System.Drawing.Size = TextRenderer.MeasureText(text, f)
            textposition = New Aspose.Imaging.PointF(x:=(img.Width - measure.Width - horizontalmargin), y:=verticalmargin)
            textformat.Alignment = Aspose.Imaging.StringAlignment.Near
            textformat.FormatFlags = Aspose.Imaging.StringFormatFlags.MeasureTrailingSpaces

        Case WatermarkPosition.Middle ' Note: verticalmargin horizontalmargin and values are ignored.
            textposition = New Aspose.Imaging.PointF(x:=(img.Width \ 2), y:=(img.Height \ 2))
            textformat.Alignment = Aspose.Imaging.StringAlignment.Center
            textformat.FormatFlags = Aspose.Imaging.StringFormatFlags.MeasureTrailingSpaces

        Case WatermarkPosition.MiddleLeft ' Note: verticalmargin value is ignored.
            textposition = New Aspose.Imaging.PointF(x:=(horizontalmargin), y:=(img.Height \ 2))
            textformat.Alignment = Aspose.Imaging.StringAlignment.Near
            textformat.FormatFlags = Aspose.Imaging.StringFormatFlags.MeasureTrailingSpaces

        Case WatermarkPosition.MiddleRight ' Note: verticalmargin value is ignored.
            Dim f As New System.Drawing.Font(fnt.Name, fnt.Size, DirectCast(fnt.Style, System.Drawing.FontStyle))
            Dim measure As System.Drawing.Size = TextRenderer.MeasureText(text, f)
            textposition = New Aspose.Imaging.PointF(x:=(img.Width - measure.Width - horizontalmargin), y:=(img.Height \ 2))
            textformat.Alignment = Aspose.Imaging.StringAlignment.Near
            textformat.FormatFlags = Aspose.Imaging.StringFormatFlags.MeasureTrailingSpaces

        Case WatermarkPosition.Bottom ' Note: horizontalmargin value is ignored.
            Dim f As New System.Drawing.Font(fnt.Name, fnt.Size, DirectCast(fnt.Style, System.Drawing.FontStyle))
            Dim measure As System.Drawing.Size = TextRenderer.MeasureText(text, f)
            textposition = New Aspose.Imaging.PointF(x:=(img.Width \ 2), y:=(img.Height - measure.Height - verticalmargin))
            textformat.Alignment = Aspose.Imaging.StringAlignment.Center
            textformat.FormatFlags = Aspose.Imaging.StringFormatFlags.MeasureTrailingSpaces

        Case WatermarkPosition.BottomLeft
            Dim f As New System.Drawing.Font(fnt.Name, fnt.Size, DirectCast(fnt.Style, System.Drawing.FontStyle))
            Dim measure As System.Drawing.Size = TextRenderer.MeasureText(text, f)
            textposition = New Aspose.Imaging.PointF(x:=(horizontalmargin), y:=(img.Height - measure.Height - verticalmargin))
            textformat.Alignment = Aspose.Imaging.StringAlignment.Near
            textformat.FormatFlags = Aspose.Imaging.StringFormatFlags.MeasureTrailingSpaces

        Case WatermarkPosition.BottomRight
            Dim f As New System.Drawing.Font(fnt.Name, fnt.Size, DirectCast(fnt.Style, System.Drawing.FontStyle))
            Dim measure As System.Drawing.Size = TextRenderer.MeasureText(text, f)
            textposition = New Aspose.Imaging.PointF(x:=(img.Width - measure.Width - horizontalmargin), y:=(img.Height - measure.Height - verticalmargin))
            textformat.Alignment = Aspose.Imaging.StringAlignment.Near
            textformat.FormatFlags = Aspose.Imaging.StringFormatFlags.MeasureTrailingSpaces

    End Select

    Using brush As New Aspose.Imaging.Brushes.SolidBrush With {.Color = color, .Opacity = 100.0F}

        ' Create and initialize an instance of Graphics class.
        Dim g As New Aspose.Imaging.Graphics(img)

        ' Draw a String using the SolidBrush object and Font, at specific Point and with specific format.
        g.DrawString(s:=text, font:=fnt, brush:=brush, point:=textposition, format:=textformat)

    End Using

    textformat.Dispose()

    ' Return the modified image.
    Return img

End Function

''' <summary>
''' Specifies a Watermark position
''' </summary>
Public Enum WatermarkPosition As Short

    ''' <summary>
    ''' Top position.
    ''' horizontalmargin value is ignored.
    ''' </summary>
    Top = 0S

    ''' <summary>
    ''' Top-Left position.
    ''' </summary>
    TopLeft = 1S

    ''' <summary>
    ''' Top-Right position.
    ''' </summary>
    TopRight = 2S

    ''' <summary>
    ''' Middle-Left position.
    ''' verticalmargin value is ignored.
    ''' </summary>
    MiddleLeft = 3S

    ''' <summary>
    ''' Middle position.
    ''' verticalmargin and horizontalmargin values are ignored.
    ''' </summary>
    Middle = 4S

    ''' <summary>
    ''' Middle-Right position.
    ''' verticalmargin value is ignored.
    ''' </summary>
    MiddleRight = 5S

    ''' <summary>
    ''' Bottom position.
    ''' horizontalmargin value is ignored.
    ''' </summary>
    Bottom = 6S

    ''' <summary>
    ''' Bottom-Left position.
    ''' </summary>
    BottomLeft = 7S

    ''' <summary>
    ''' Bottom-Right position.
    ''' </summary>
    BottomRight = 8S

End Enum

Usage:

Imports Aspose.Imaging

Public Class Form1

Private Sub Form1_Load() Handles MyBase.Load

    ' Load an image to add a watermark.
    Dim img As Aspose.Imaging.Image = Aspose.Imaging.Image.Load("C:\sample.bmp")

    ' Set the watermark text.
    Dim text As String = "ElektroStudios"

    ' Set the watermark text color.
    Dim color As Aspose.Imaging.Color = Aspose.Imaging.Color.White

    ' Set the watermark text font.
    Dim fnt As New Aspose.Imaging.Font("Lucida Console", 32, FontStyle.Bold)

    ' Add the watermark into the image.
    img = Me.AddWatermark(img:=img, text:=text, fnt:=fnt, color:=color, 
                          position:=WatermarkPosition.BottomRight)

    ' Or...
    ' Dim position As New Aspose.Imaging.PointF(x:=10, y:=10)
    ' img = Me.AddWatermark(img:=img, text:=text, fnt:=fnt, color:=color, 
    '                       position:=position)

    ' Save the image to disk.
    img.Save("C:\Watermark.bmp")

    ' See the resulting image.
    Process.Start("C:\Watermark.bmp")
    Application.Exit()

End Sub

End Class

Answer 2

'Create an instance of Image and load an existing image
Using image As Aspose.Imaging.Image = Aspose.Imaging.Image.Load("c://temp//sample.bmp")
    'Create and initialize an instance of the Graphics class
    Dim graphics As New Aspose.Imaging.Graphics(image)
    'Creates an instance of Font
    Dim font As New Aspose.Imaging.Font("Times New Roman", 16, Aspose.Imaging.FontStyle.Bold)

    'Create an instance of SolidBrush and set its various properties
    Dim brush As New Aspose.Imaging.Brushes.SolidBrush()
    brush.Color = Aspose.Imaging.Color.Black
    brush.Opacity = 100

    'Draw a String using the SolidBrush object and Font, at specific Point
    graphics.DrawString("Aspose.Imaging for .Net", font, brush, New Aspose.Imaging.PointF(image.Width/2, image.Height/2))

    ' Export to PNG file format using default options.
    image.Save("out.bmp",New Aspose.Imaging.ImageOptions.PngOptions())
End Using

Adding a Watermark to an Image