add alpha a wx.bitmap

wxPython Users
1

How would you go about adding a alpha, lets say 20% alpha,
to a wx.bitmap so that when you draw it on a wx.dc it will appear faded or like
a watermark? Would I have to turn to a external library like PIL?

2

Keith Lackey wrote:

How would you go about adding a alpha, lets say 20% alpha, to a wx.bitmap so that when you draw it on a wx.dc it will appear faded or like a watermark? Would I have to turn to a external library like PIL?

It can be done with wx.Image. Perhaps something like this would work:

  img = wx.ImageFromBitmap(theBitmap)
  if not img.HasAlpha():
    img.InitAlpha()
  w,h = img.GetSize()
  alphadata = chr(51) * w*h # 51 is 20% of 255
  img.SetAlphaData(alphadata)
  newBitmap = img.ConvertToBitmap()

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