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Re: Image overlay

This solution escaped me at the time of my previous post.  The result of
using alpha blending to combine two pixels can be easily calculated:

result = ALPHA * srcPixel + ( 1 - ALPHA ) * destPixel


ALPHA - ranges from 0.0 to 1.0
result - Is the alpha blended color
srcPixel - Is the foreground pixel
destPixel- Is the background pixel

with an alpha of 0.0 the result will be the background pixel and with an
alpha of 1.0 the result will be the foreground pixel.


"Rick Towler" <rtowler@u.washington.edu> wrote in message
> this should be in the FAQ if it isn't already....
> You can take the approach outlined by Craig or you can go the transparancy
> route.  If you go down this road be aware that it is best done in object
> graphics.  Take a look at David Fanning's IMAGE_BLEND program found at:
> http://www.dfanning.com/documents/programs.html
> -Rick
> "Raymond Pete" <raymond.pete@maine.edu> wrote in message
> Xns9094D67984AC6raymondpetemaineedu@">news:Xns9094D67984AC6raymondpetemaineedu@
> > Need some help here guys.. if u dont mind..
> >
> > I have a Tire displayed using tv.. I also below that have an image file
> > that i have read in using a function i wrote to read a proprietarty
> > extension displayed in a 2d section.. my issue is i want to overlay the
> > data image file onto the Tire to show the properties as such.. any
> > functions or advice would be GREATLY appreciated..
> >
> > NOTE: the image file is setup as an 8-bit RBG file one byte per pixel..
> >