Non 32-Bit Images

AWicons allows you to edit non-alpha images with the anti-aliasing mode enabled. The resulting image can contain semitransparent pixels, which should be converted during the saving process into either fully opaque or fully transparent pixels (if the saving format allows). The program performs the conversion automatically, but you can control this process by changing two parameters:

• alpha threshold - determines if the pixel is transparent or opaque. If the source pixel has an alpha value below threshold, the pixel becomes transparent. If the source alpha value is above threshold, the pixel becomes opaque and its color will be combined with the matte color.
  
  
• matte color - this color is used for converting semitransparent pixels to opaque.

You should adjust these parameters according to hypothetical background color used for the saved image. For instance, let's try to save a 32-bit image of the blue circle in GIF format (which is restricted to only 8-bit images):

• If the background color is known and solid, we'll set the alpha threshold value to 1 and the matte color value to the background color (white in our example).
  
  The quality of the resulting image will be just fine on the white background, but unacceptable on the dark one:
  
  

  the source image

  the 8-bit image on a white background

  the 8-bit image on a dark background

  
  
• If the background color is between light gray and white, set the alpha threshold to 1, and the matte color to light gray.
  
  The resulting image will have a nice quality on light backgrounds:
  
  

  the source image

  the 8-bit image on a light gray background

  the 8-bit image on a white background

  
  
• If the background color can be of any density, set the alpha threshold value to 78, and matte color set to gray:
  
  

  the source image

  the 8-bit image on a black background

  the 8-bit image on a white background