RGB question

[mrdj1002]

Hi guys
Well I need to find out the darkness or brightness of each single pixle of a given image file in my app. To do this I use a picturebox, I load the image into it then I get each pixel’s color using point method. It returns a long RGB number which is the result of merging red, green and blue I guess. 4 example if the point is RGB(192,255,12) it returns 192255012. but there is one problem:
When it is RGB(0,255,0)(pure green) it returns 225
When it is RGB(0,0,255) (pure blue) it returns 225 also
So u see there’s no difference in green and blue using this. So I decided to anlaize these rgb colors. For example I have a point now I want to find out how much red is in it? How much green and how much blue? Do u know how to this?
Thanks aloot

[AIS_DK]

This will do it

lngRed = (lngColor And &HFF&)
lngGreen = (lngColor And &HFF00&) / &H100
lngBlue = (lngColor And &HFF0000) / &H10000

[mrdj1002]

can u explain a little more please?
thank u

[AIS_DK]

Weel, I'm not sure what else I can say about the code, it is rather self explaning.

But here goes:
lngColor is a colorcode ie. 192255012
lngRed is the value of red in the RGB colorcode
lngGreen is the value of green in the RGB colorcode
lngBlue is the value of blue in the RGB colorcode

lngRed = (lngColor And &HFF&) 'lngRed is now the value of red
lngGreen = (lngColor And &HFF00&) / &H100 'lngGreen is now the value of green
lngBlue = (lngColor And &HFF0000) / &H10000 'lngBlue is now the value of blue

lngRed, Green and Blue are just varibles, in which I store the value, you can choose your own varibles, debug it or whatever.

The code just does some bitwise operations on the number, and retrieves the bits representing the value of the Red Green and Blue value.

[mrdj1002]

u know i'm a little confused with the format of the codelngRed = 4 example i can't see any functions or stuff. i'm looking 4 a way to analize the valum that point method returns to me (lngColor And &HFF&)
hey it seems i'm getting old at 20

[Joacim Andersson]

OK. I implemented the code that AIS_DK provided into a simple to use function. Add the following code to your Form

Public Enum eRGBcolor
    rgbRed = 1
    rgbGreen
    rgbBlue
End Enum
    
Private Function GetColorValue(nColor As Long, nReturnColor As eRGBcolor) As Integer
    Select Case nReturnColor
        Case rgbRed
            GetColorValue = (nColor And &HFF&)
        Case rgbGreen
            GetColorValue = (nColor And &HFF00&) / &H100
        Case rgbBlue
            GetColorValue = (nColor And &HFF0000) / &H10000
        Case Else
            Err.Raise vbObjectError + 512, "GetColorValue", "Incorrect color for return value"
    End Select
End Function

Now to get, for example, the value of red at the position 1, 1 in a picturebox named Picture1 you'll use code simular to this:

MsgBox GetColorValue(Picture1.Point(1, 1), rgbRed)

Best regards

[AIS_DK]

It's not a function. It's just 3 calculations, that's it.

So how about this then.

Dim lngPointColor as long
 
lngPointColor = Me.PictureBox1.Point(X_Coor, Y_Coor)
 
Debug.print "Amount of Red in Coordinate: " & (lngPointColor And &HFF&) 
Debug.print "Amount of Green in Coordinate: " & (lngPointColor And &HFF00&) / &H100 
Debug.print "Amount of Blue in Coordinate: " & (lngPointColor And &HFF0000) / &H10000

[mrdj1002]

thanks i'll try it