AlphaMix 1.2
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(c) Willem van Schaik, 1999
    willem@schaik.com
    December 1999

see http://www.schaik.com/png/alphamix.html
and http://www.schaik.com/png/antialias.html
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The latest versions of Netscape, IExplorer and Opera are supporting PNG 
images. However, all of them don't handle transparency, alpha and 
background colors correctly. Therefore I wrote this small Windows-95/NT 
program that demonstrates how proper support of alpha-channels should 
be done. AlphaMix allows you to display PNG images, probably with an 
alpha-channel or a transparency chunk, against either a background 
image or against the color specified using a background chunk.

Similar to web-browsers, by default the background image will be 
"tiled" to fill the whole window. Using the menu this option can be 
changed to "centered". When no background image is loaded, when 
present, the color of the background chunk will be used. Also this 
option can be disabled.

To get going, after downloading AlphaMix and extracting the zip-file, 
start the program and open test_img.png as foreground image (ctrl-O). 
You will see the PNG 3-D logo against the color in the background 
chunk. Look how no artifacts of anti-aliasing are visible. Now open 
test_bkg.png as the background image (ctrl-B). The background color 
disappears and is replaced by a tiled checkboard pattern. Playing 
around with the menu options will enable you to get all the different 
views shown above.

Finally you are able to save the combination of the (tiled) background 
and the (semi-) transparent foreground image into a PNG-file. This 
output file itself will not have any alpha-channel or transparency.


RELEASE HISTORY

Version 1.0 - September 1999
  - first version

Version 1.1 - December 1999
  - bug fixed related to initial background color
  - filename on command-line is used as image to be viewed; set File-
    type in Explorer to make AlphaMix the default PNG image-viewer
  - moved alpha and background color options to File menu
  - added support to restore latest background image

Version 1.2 - December 1999
  - bug fixed related to striping in background
  - smoother coloring of background when resizing


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