Converting a color to black&white. How?

[Arie]

Hi, Guys!

How can I change a value of a color to his black&white value?

Thank you,
Arie.

[abdul]

Private Function GetBVPixel(colour As Long) As Integer
Dim r, g, b As Integer
Dim averagec As Integer
r = colour And 255
g = (colour / 256) And 255
b = colour / 65536
'get the average colour of those RGB values
averagec = (r + g + b) / 3
GetBVPixel = averagec
End Function

The value return is Red, Green, and Blue values of the pixel. All 3 will be same so here is its use:

Dim p As Integer
Picture1.ScaleMode = vbPixels
For y% = 0 To Picture1.ScaleHeight
For x% = 0 To Picture1.ScaleWidth
p = GetBVPixel(Picture1.Point(x%, y%))
Picture1.PSet (x%, y%), RGB(p, p, p)
Next
Next

[riis]

Green is quite a lot lighter than red, but blue is pretty much darker. You can better use weighted values.

BlackWhite = 1/3 * red + 1/2 * green + 1/6 * blue usually gives a better result.

[Sastraxi]

The exact values can be found from a German site... there is a tutorial, translated, by him at Lucky's and it gives a link to his site. I think it's vbempire.de.

[Arie]

Thank you,
Arie.

now.at/ariecoolsite

[jim mcnamara]

Several of us have posted code on calculating luminosity for a pixel.

If you want the graphic to look like a B&W photograph, you have to do this to have it look okay.

For each pixel, get the luminosity value, like 122 - then
apply it to the pixel - pixel = RGB(122,122,122)

Here is one thread; the search engine can't find what I posted, but this will get you going.

http://www.vbforums.com/showthread.p...ght=luminosity