regarding threshold

[raju]

What are the options given to threshold and how it works ??

[anthony]

Threshold Images
http://imagemagick.org/Usage/quantize/#threshold

[nsh]

I found that using % instead of for example 255,255,255 was wery logic when using function WhiteThresholdImage.

I'm setting all pixels above 250 to white, 250 is 98% of 255.
so my call to WhiteThresholdImage with 98% as threshold , did the job.

[anthony]

Using percent is preferable as it will work for ALL 'Q' levels of IM.
not just Q8. Basially it is not just a percentage but a floating point specification giving very fine control.