[XtraChartsLocalizableCategory(XtraChartsCategory.Behavior)]
public ChartImageSizeMode SizeMode { get; set; }

<XtraChartsLocalizableCategory(XtraChartsCategory.Behavior)>
Public Property SizeMode As ChartImageSizeMode

#region #usings
using System;
using System.Drawing;
using System.IO;
using System.Windows.Forms;
using DevExpress.Drawing;
using DevExpress.XtraCharts;
// ...
#endregion #usings

namespace AnnotationsSample {
    public partial class Form1 : Form {
        public Form1() {
            InitializeComponent();
        }

        #region #generalcode
        private void Form1_Load(object sender, EventArgs e) {
            // Add a text annotation to the chart control's repository.
            chartControl1.AnnotationRepository.Add(new TextAnnotation("Annotation 1"));

            // And, assign a series point to the annotation's AnchorPoint property.
            // This adds the annotation to the series point's Annotations collection.
            chartControl1.AnnotationRepository[0].AnchorPoint =
                new SeriesPointAnchorPoint(chartControl1.Series[0].Points[2]);

            // Now, create an image annotation, and add it to the chart's collection.
            chartControl1.Annotations.AddImageAnnotation("Annotation 2",
                DXImage.FromStream(new FileStream(@"...\...\image.png", FileMode.Open, FileAccess.Read, FileShare.Read)));

            // Define the X and Y absolute coordinates for the annotation, in pixels.
            ((ChartAnchorPoint)chartControl1.Annotations[0].AnchorPoint).X = 150;
            ((ChartAnchorPoint)chartControl1.Annotations[0].AnchorPoint).Y = 150;

            // Obtain the additional pane from the diagram's collection.
            XYDiagramPaneBase myPane = ((XYDiagram)chartControl1.Diagram).Panes[0];

            // And, position the chart's annotation in this pane's right top corner;
            ((FreePosition)chartControl1.Annotations[0].ShapePosition).DockTarget = myPane;
            ((FreePosition)chartControl1.Annotations[0].ShapePosition).DockCorner = DockCorner.RightTop;

            // Another annotation is now being added to the collection of this pane.
            myPane.Annotations.AddImageAnnotation("Annotation 3",
                DXImage.FromStream(new FileStream(@"...\...\image.png", FileMode.Open, FileAccess.Read, FileShare.Read)));

            // Define its axis coordinates (in units appropriate for the scale type of the axes).
            ((PaneAnchorPoint)myPane.Annotations[0].AnchorPoint).AxisXCoordinate.AxisValue = 2;
            ((PaneAnchorPoint)myPane.Annotations[0].AnchorPoint).AxisYCoordinate.AxisValue = 180;

            // Position the annotation in relation to its anchor point.
            ((RelativePosition)myPane.Annotations[0].ShapePosition).Angle = -135;
            ((RelativePosition)myPane.Annotations[0].ShapePosition).ConnectorLength = 50;

            // You can get an annotation either via the collection of the element to which it is anchored,
            // or centrally, via the chart control's repository (e.g. by its name).
            TextAnnotation myTextAnnotation =
                (TextAnnotation)chartControl1.AnnotationRepository.GetElementByName("Annotation 1");
            ImageAnnotation myImageAnnotation =
                (ImageAnnotation)chartControl1.AnnotationRepository.GetElementByName("Annotation 3");

            // Define the text for the text annotation.
            myTextAnnotation.Text = "<i>Basic</i> <b>HTML</b> <u>is</u> <color=blue>supported</color>.";

            // Enable the interactive positioning for the image annotation.
            myImageAnnotation.RuntimeMoving = true;
            myImageAnnotation.RuntimeAnchoring = true;
            myImageAnnotation.RuntimeResizing = true;
            myImageAnnotation.RuntimeRotation = true;

            // Specify image annotation size mode.
            myImageAnnotation.SizeMode = ChartImageSizeMode.Tile;

            // And, adjust image annotation appearance options.
            myImageAnnotation.ShapeKind = ShapeKind.RoundedRectangle;
            myImageAnnotation.ShapeFillet = 10;
            myImageAnnotation.ConnectorStyle = AnnotationConnectorStyle.Arrow;
        }
        #endregion #generalcode

    }
}

#Region "#usings"
Imports System
Imports System.Drawing
Imports System.IO
Imports System.Windows.Forms
Imports DevExpress.Drawing
Imports DevExpress.XtraCharts

' ...
#End Region ' #usings
Namespace AnnotationsSample

    Public Partial Class Form1
        Inherits Form

        Public Sub New()
            InitializeComponent()
        End Sub

#Region "#generalcode"
        Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs)
            ' Add a text annotation to the chart control's repository.
            chartControl1.AnnotationRepository.Add(New TextAnnotation("Annotation 1"))
            ' And, assign a series point to the annotation's AnchorPoint property.
            ' This adds the annotation to the series point's Annotations collection.
            chartControl1.AnnotationRepository(0).AnchorPoint = New SeriesPointAnchorPoint(chartControl1.Series(0).Points(2))
            ' Now, create an image annotation, and add it to the chart's collection.
            chartControl1.Annotations.AddImageAnnotation("Annotation 2", DXImage.FromStream(New FileStream("...\...\image.png", FileMode.Open, FileAccess.Read, FileShare.Read)))
            ' Define the X and Y absolute coordinates for the annotation, in pixels.
            CType(chartControl1.Annotations(0).AnchorPoint, ChartAnchorPoint).X = 150
            CType(chartControl1.Annotations(0).AnchorPoint, ChartAnchorPoint).Y = 150
            ' Obtain the additional pane from the diagram's collection.
            Dim myPane As XYDiagramPaneBase = CType(chartControl1.Diagram, XYDiagram).Panes(0)
            ' And, position the chart's annotation in this pane's right top corner;
            CType(chartControl1.Annotations(0).ShapePosition, FreePosition).DockTarget = myPane
            CType(chartControl1.Annotations(0).ShapePosition, FreePosition).DockCorner = DockCorner.RightTop
            ' Another annotation is now being added to the collection of this pane.
            myPane.Annotations.AddImageAnnotation("Annotation 3", DXImage.FromStream(New FileStream("...\...\image.png", FileMode.Open, FileAccess.Read, FileShare.Read)))
            ' Define its axis coordinates (in units appropriate for the scale type of the axes).
            CType(myPane.Annotations(0).AnchorPoint, PaneAnchorPoint).AxisXCoordinate.AxisValue = 2
            CType(myPane.Annotations(0).AnchorPoint, PaneAnchorPoint).AxisYCoordinate.AxisValue = 180
            ' Position the annotation in relation to its anchor point.
            CType(myPane.Annotations(0).ShapePosition, RelativePosition).Angle = -135
            CType(myPane.Annotations(0).ShapePosition, RelativePosition).ConnectorLength = 50
            ' You can get an annotation either via the collection of the element to which it is anchored,
            ' or centrally, via the chart control's repository (e.g. by its name).
            Dim myTextAnnotation As TextAnnotation = CType(chartControl1.AnnotationRepository.GetElementByName("Annotation 1"), TextAnnotation)
            Dim myImageAnnotation As ImageAnnotation = CType(chartControl1.AnnotationRepository.GetElementByName("Annotation 3"), ImageAnnotation)
            ' Define the text for the text annotation.
            myTextAnnotation.Text = "<i>Basic</i> <b>HTML</b> <u>is</u> <color=blue>supported</color>."
            ' Enable the interactive positioning for the image annotation.
            myImageAnnotation.RuntimeMoving = True
            myImageAnnotation.RuntimeAnchoring = True
            myImageAnnotation.RuntimeResizing = True
            myImageAnnotation.RuntimeRotation = True
            ' Specify image annotation size mode.
            myImageAnnotation.SizeMode = ChartImageSizeMode.Tile
            ' And, adjust image annotation appearance options.
            myImageAnnotation.ShapeKind = ShapeKind.RoundedRectangle
            myImageAnnotation.ShapeFillet = 10
            myImageAnnotation.ConnectorStyle = AnnotationConnectorStyle.Arrow
        End Sub
#End Region ' #generalcode
    End Class
End Namespace

' Specify image annotation size mode.
myImageAnnotation.SizeMode = ChartImageSizeMode.Tile
' And, adjust image annotation appearance options.