Posted: 2006-02-14T16:35:24-07:00
Color blend is generally not overlay. The blend is implemented in IM as -blend. http://www.cit.gu.edu.au/~anthony/graph ... 6/compose/
This merges two images by picking a percentage of each image to
do a sort of 'weighted average'. This is probably what Photoshop is doing.
If this does not do what you want, by overlay is nearly right, my suggestion is to DIY it.
If you look at the SVG Composition Math manual pointer
http://www.w3.org/TR/2004/WD-SVG12-2004 ... mp-op-prop
I have in my Alpha Composition Example Page
http://www.cit.gu.edu.au/~anthony/graph ... 6/compose/
You can use those formulas to implement the overlay using -fx in a IM API.
(just ignore the transparent parts).
From there you can add a 'blend' percentage to adjust the results.
If this works well. perhaps you would like to look at the "compose.c" source in the IM core, and implement a 'overlay-blend' type of composition of others to use.
IM is really needing more programmers to add and improve features.
This merges two images by picking a percentage of each image to
do a sort of 'weighted average'. This is probably what Photoshop is doing.
If this does not do what you want, by overlay is nearly right, my suggestion is to DIY it.
If you look at the SVG Composition Math manual pointer
http://www.w3.org/TR/2004/WD-SVG12-2004 ... mp-op-prop
I have in my Alpha Composition Example Page
http://www.cit.gu.edu.au/~anthony/graph ... 6/compose/
You can use those formulas to implement the overlay using -fx in a IM API.
(just ignore the transparent parts).
From there you can add a 'blend' percentage to adjust the results.
If this works well. perhaps you would like to look at the "compose.c" source in the IM core, and implement a 'overlay-blend' type of composition of others to use.
IM is really needing more programmers to add and improve features.