Is it shadow bug?

Questions and postings pertaining to the usage of ImageMagick regardless of the interface. This includes the command-line utilities, as well as the C and C++ APIs. Usage questions are like "How do I use ImageMagick to create drop shadows?".
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Is it shadow bug?

Post by excel »

This code works on two servers with different ImageMagick versions.

Code: Select all

exec("convert -size 200x200 xc:transparent -fill 'rgba(255, 87, 34, 0.5)' -draw 'circle 95,95 30,35'  \( +clone -background black -shadow 70x3+1+1 \) +swap -background none -layers merge +repage result.png");
Both servers based in Debian operating system.

First server:
ImageMagick 6.9.2-7 Q16 x86_64 2015-12-03

Second server:
ImageMagick 6.8.9-9 Q16 x86_64 2015-01-05

Why the different results?

From first server:

From second server:

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Re: Is it shadow bug?

Post by fmw42 »

I can confirm the difference using IM Q16 and Q16 Mac OSX Snow Leopard. I know there was some partial transparency blending changes not too long ago, but do not know if this is related. The change seems to have occurred between and

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Re: Is it shadow bug?

Post by magick »

It appears to be a transient problem which fixed in recent releases of ImageMagick. The current release, ImageMagick 6.9.2-10, returns similar results to your first image, res1.png. The normalized RMSE metric for 6.9.2-10 vs 6.9.2-7 is 5.8503e-06, whereas for 6.8.9-9 vs 6.9.2-7, we get an RMSE of 0.0323784.