converting byte data to Drawing.Color

[homer13j]

I'm writing a simple app to open Grand Prix Legends' funky PBF files used to store screenshot bitmaps in 16-bit rgb 565 format where each pixel's color is represented by two bytes.

SetPixel requires a Color parameter. How do I convert those two bytes to System.Drawing.Color type?

Thanks,
Homer

[jmcilhinney]

Check the Color.FromArgb method.

[homer13j]

ToARGB/FromARGB will not accept a two byte color value. RGB 565 uses 5 bits for red, 6 bits for green, and 5 bits for blue. ARGB uses one byte each for alpha, red, green, and blue.

I am having limited success using the color translator:

pixColor = ColorTranslator.FromWin32(buffer(i + 1) * &H100 Or buffer(i))
imgbmp.SetPixel(x, y, pixColor)

Unfortunately the resulting image looks like it came from a monochrome monitor.

Is there a similar method like ToARGB that accepts a two-byte color value that I don't know about?

[Boumxyz2]

Maybe you want something like this.. I didn't test it.



EXAMPLE :

 Dim b As Integer
            b = 65535
            Const RED As Integer = 63488
            Const green As Integer = 2016
            Const blue As Integer = 31

            Const MaxRed As Integer = 31
            Const MaxGreen As Integer = 63
            Const MaxBlue As Integer = 31

            Dim bred As Integer = (b And RED)
            Dim bgreen As Integer = (b And green)
            Dim bblue As Integer = (b And blue)

            bred = bred >> 11 ' ------ > Takes out the 0 
            bgreen = bgreen >> 5 ' ----- > takes out the 0

            Dim flBred As Decimal = (bred \ MaxRed)    'Now you got the red proportion in byte
            Dim flbgreen As Decimal = (bgreen \ MaxGreen)
            Dim flbblue As Decimal = (bblue \ MaxBlue)

            bred = CInt(flBred * 255)
            bgreen = CInt(flbgreen * 255)
            bblue = CInt(flbblue * 255)

            Dim newColor As System.Drawing.Color

            newColor = New System.Drawing.Color

            newColor.FromArgb(bred, bgreen, bblue)

[homer13j]

Thanks, Nicolas. I was stumped on how to separate the individual bits.

But VB.net won't let me use the C++ extraction operator (>>). Is there a VB equivalent?

[Boumxyz2]

the >> operator in vb.net is the SHIFT operator


>> = shift right
<< = shift left

I'm doing the >> shift thing.. I don't see why you need to extract something..


If you mean read the data from a file or something then you need to check with stream classes I think.

But I thought you had your bits in memory