chess board in a circle

[manit]

Do not resurrect old topics for a new problem, post split to new topic -- Ant


I drew a chessboard using

convert -size 8x8 pattern:gray50 -scale 10100% chessboard.png
Then I drew a circle over it
convert.exe chessboard.jpg -fill none -stroke red -draw "circle 353,253 504,201" my-icon.jpg
Now I want that circle to appear as 3d .
it is something about alpha channel inside area covered by circle . Still , I am not able to find a way ?

Please help.
Thank You.

[anthony]

How do you want to make the 'circle' appear 3-D.

Shading?
Surface distortion?

Have a look at IM Examples, Image Maps.
http://www.imagemagick.org/Usage/mapping/#spherical
This uses DIY created 'mapped' distortions to generate a sphere-like image mapping. But also does spherical shading.

[manit]

taking cue from
'Draw Dim Box' in http://www.imagemagick.org/Usage/annotating/
I just replaced -fill none with -fill '#0008' which makes my circle more noticeable on chess board .
I tried
convert.exe my-icon.jpg ( +clone -blur 0x20 -shade 110x21.7 -contrast-stretch 0% +sigmoidal-contrast 6x50% -fill grey50 -colorize 10% ) -composite sphere_overlay.jpg

on my windows 7 OS but it acted on whole image instead of just that circle which I want to highlight