Runtime error message Index was outside the bounds of the array. for Visual Basic 2010 - vb.net

Question

I am computing the ROI with a moving rectangle and extracting the ROI to compute the standard deviation, mean, area and Pixel value coordinates X and Y in a seperate form2 by clicking the mouse. At this juncture I am trying to pass a function from the main Form that loads the Image and displays the rectangle to another Form that has the displayed properties of the mean and standard deviation etc. However, I'm receiving errors in runtime in the function that contains the standard deviation. The error displayed is
Index was outside the bounds of the array.
It is displayed at the end of this portion of the code in the function StD, i.e at the end of the mean part'
SD(count) = Double.Parse(pixelcolor.R) + Double.Parse(pixelcolor.G) + Double.Parse(pixelcolor.B) - mean
what is this actually saying and how can I fix this situation. Any tips and ideas, thanks.
My code is at the bottom
enterPublic Function StD(ByVal image As Bitmap, ByVal mean As Double, ByVal meancount As Integer) As Double
Dim SD(SquareHeight * SquareWidth) As Double
Dim count As Integer = 0
For i = 0 To SquareWidth
For j = 0 To SquareHeight
Dim pixelcolor As Color = image.GetPixel(i, j)
SD(count) = Double.Parse(pixelcolor.R) + Double.Parse(pixelcolor.G) + Double.Parse(pixelcolor.B) - mean
count += 1
Next
Next
Dim SDsum As Double = 0
For i = 0 To count
SDsum = SDsum + SD(i)
Next
SDsum = SDsum / (SquareHeight * SquareWidth)
SDsum = ((SDsum) ^ (1 / 2))
Return SDsum
End Function code here
I would like to pass this using the code below
enterPrivate Sub PictureBox1_MouseDown(ByVal sender As System.Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseDown
Dim mean As Double = 0
Dim meancount As Integer = 0
Dim bmap As New Bitmap(400, 400)
bmap = PictureBox1.Image
Dim colorpixel As Color = bmap.GetPixel(e.X, e.Y)
' Dim pixels As Double = colorpixel.R + colorpixel.G + colorpixel.B
If e.Button = Windows.Forms.MouseButtons.Left AndAlso Rect.Contains(e.Location) Then
If (PictureBox1.Image Is Nothing) Or (PictureBox1.Height - (e.Y + SquareHeight) < 0) Or (PictureBox1.Width - (e.X + SquareWidth) < 0) Then
Else
Dim ROI As New Bitmap(400, 400)
Dim x As Integer = 0
Dim countx As Integer = 0
Dim county As Integer = 0
For i = e.X To (e.X + SquareWidth)
For j = (e.Y + x) To (e.Y + SquareHeight)
Dim pixelcolor As Color = bmap.GetPixel(i, j)
ROI.SetPixel(countx, county, pixelcolor)
mean = mean + pixelcolor.R + pixelcolor.G + pixelcolor.B
county += 1
meancount += 1
Next
county = 0
countx += 1
x = x + 1
Next
mean = mean / (meancount * 3)
Dim SD = mean - 75
Dim area As Integer = (SquareHeight * SquareWidth)
Dim anotherForm As Form2
anotherForm = New Form2(mean, StD(bmap, mean, meancount), area, 34)
anotherForm.Show()
End If
End If
' Catch ex As Exception
' MessageBox.Show(ex.Message())
' End Try
End Sub code here
To be displayed with this code
enter Public Sub New(ByVal mean As Double, ByVal StD As Double, ByVal Area As Integer, ByVal pixel As Double)
MyBase.New()
InitializeComponent()
TextBox1.Text = mean.ToString()
TextBox2.Text = StD.ToString()
TextBox3.Text = Area.ToString()
TextBox4.Text = pixel.ToString()
End Sub code here

Answer 1

The problem probably is because of these lines:
For i = 0 To SquareWidth
For j = 0 To SquareHeight
Try using this instead:
For i = 0 To SquareWidth - 1
For j = 0 To SquareHeight - 1