Re: Dark veil with convert resize and unsharp

>I'm using imagemagick with enthousiasm; a couple of days ago I had 
>an unexepected behavior.  I generate thumbnails using ` convert 
>$original -resize x$taille -unsharp 0.5x0.5+0.75+0.05 $thumbname` 
>but got a weird result on this specific image: see: 
>http://stdin.fr/misc/original.jpg http://stdin.fr/misc/thumbnail.jpg
>
>Any idea on what it could be and how to fix it ?


I don't know if this is the problem, but in -unsharp, the first 
parameter is the radius in pixels and should be an integer (floats 
will be allowed, but the fraction may be rounded or truncated). If 
you don't know the radius, just use 0 and the sigma will be used to 
calculate the radius.

Also do and identify -verbose on your input image and see if it is 
cmyk and not rgb. It may be that -unsharp relies upon the image in 
rgb space.

Also what version of IM are you using?

If old, perhaps upgrade.

Fred