IM6 vs 7: Convolve with bias 50% differ

[7eicher]

Hi folks,

I was using convert in IM6 to create the edges with the convolve method successfully like that:

Code: Select all

convert file.jpg -bias 50% -morphology Convolve loG:0x2 edge.jpg

Using now IM7 with the exact same command results in a totally white image:

Code: Select all

magick file.jpg -bias 50% -morphology Convolve loG:0x2 edge.jpg

Is this intentionally or a bug? I am using for IM7 this windows pre-build from http://blog.astrophotographytargets.com ... n-windows/ with FFTW support.

Source image:



IM6 bias 50%:



IM7 bias 50%:



IM7 bias 0%:

[snibgo]

That version is two years old. So it will have whatever bugs v6 had at that time, plus whatever bugs were introduced by the pre-release v7.

You might try this with a recent build of v7.

If I were you, I would use v7 only for operations that need it. In your case, this is just fft.

[7eicher]

makes sense... thanks!

[fmw42]

I have tested your command and image on my Mac OSX Snow Leopard with IM 6.9.0.0 Q16 and IM 7 beta Q16 HDRI (Dec 20, 2014) and the two results agree visually. However, they are somewhat different (and likely more correct) than your IM 6 version. Your LoG 0x2 looks too sharp. You do not say what version of IM 6 you are using and it might be old or have a bug. Always best to identify your version of IM and platform.

[fmw42]

I am using for IM7 this windows pre-build from http://blog.astrophotographytargets.com ... n-windows/ with FFTW support.

Installation of FFTW on Windows and Ubuntu can be found at viewtopic.php?f=4&t=14251