Pixel colour

[PaulB]

Hi

I need to find out the RGB of a pixel from a picture box control.

When I use Picture1.Point(x, y) it return a long integer.

Is there anyway to convert this into seperate RGB colours to store in variables?

[Judd]

The valid range for a normal RGB color is 0 to 16,777,215 (&HFFFFFF&). Each color setting (property or argument) is a 4-byte integer. The high byte of a number in this range equals 0. The lower 3 bytes, from least to most significant byte, determine the amount of red, green, and blue, respectively. The red, green, and blue components are each represented by a number between 0 and 255 (&HFF).

Consequently, you can specify a color as a hexadecimal number using this syntax:

&HBBGGRR&

The BB specifies the amount of blue, GG the amount of green, and RR the amount of red. Each of these fragments is a two-digit hexadecimal number from 00 to FF. The median value is 80. Thus, the following number specifies gray, which has the median amount of all three colors:

&H808080&

Setting the most significant bit to 1 changes the meaning of the color value: It no longer represents an RGB color, but an environment-wide color specified through the Windows Control Panel. The values that correspond to these system-wide colors range from &H80000000 to &H80000015.

Note Although you can specify over 16 million different colors, not all systems are capable of displaying them accurately. For more information on how Windows represents colors, see "Working with 256 Colors" later in this chapter.

From the horses mouth

[Sam Finch]

the best way is to use the copymemory API.

Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (Destination As Any, Source As Any, ByVal Length As Long)

Private Type RGBTRIPLE
        rgbtRed As Byte
        rgbtGreen As Byte
        rgbtBlue As Byte
End Type


Private Function SplitColour(ByVal Colour As Long) As RGBTRIPLE


CopyMemory SplitColour, Colour, 3


End Function

hope this helps

[Judd]

Private Sub Picture1_MouseDown(Button As Integer, Shift As Integer, x As Single, Y As Single)
    Dim res As Long
    Dim str As String
    Dim sRed As String
    Dim sGreen As String
    Dim sBlue As String
    Dim iRed As Integer
    Dim iGreen As Integer
    Dim iBlue As Integer
    
    res = Picture1.Point(x, Y)
    str = Hex(res)
    
    sRed = Right(str, 2): iRed = CHex(sRed)
    sGreen = Mid(str, 3, 2): iGreen = CHex(sGreen)
    sBlue = Left(str, 2): iBlue = CHex(sBlue)
    
End Sub
Private Function CHex(ByVal x As String) As Long
Dim lDec As Long
Dim i As Long
Dim j As Long

For i = Len(x) To 1 Step -1
    j = 16 ^ (Len(x) - i)
    Select Case Mid$(x, i, 1)
        Case "0"
            lDec = lDec + (j * 0)
        Case "1"
            lDec = lDec + (j * 1)
        Case "2"
            lDec = lDec + (j * 2)
        Case "3"
            lDec = lDec + (j * 3)
        Case "4"
            lDec = lDec + (j * 4)
        Case "5"
            lDec = lDec + (j * 5)
        Case "6"
            lDec = lDec + (j * 6)
        Case "7"
            lDec = lDec + (j * 7)
        Case "8"
            lDec = lDec + (j * 8)
        Case "9"
            lDec = lDec + (j * 9)
        Case "A"
            lDec = lDec + (j * 10)
        Case "B"
            lDec = lDec + (j * 11)
        Case "C"
            lDec = lDec + (j * 12)
        Case "D"
            lDec = lDec + (j * 13)
        Case "E"
            lDec = lDec + (j * 14)
        Case "F"
            lDec = lDec + (j * 15)
    End Select
Next i
CHex = lDec
End Function

You should be able to do something now!!!

[PaulB]

Thanks for the help.