Possible aliasing bug when resizing an EPS with transparency to PNG

[fmw42]

In IM 6.9.9.5 Q16, there is no issue. But with IM 7.0.6.5 Q16 HDRI, when one resizes during conversion of a CMYK EPS with transparency, the result gets aliased edges. If there is no resize, the command works fine. If one pipes before resizing there is no problem. See viewtopic.php?f=1&t=32469&p=148733#p148733

PS I am using Ghostscript 9.21

[magick]

Thanks for the problem report. We can reproduce it and will have a patch to fix it in GIT master branch @ https://github.com/ImageMagick/ImageMagick later today. The patch will be available in the beta releases of ImageMagick @ https://www.imagemagick.org/download/beta/ by sometime tomorrow.

A mask associated with an image persists until it is modified or removed. This may produce unexpected results for complex command-lines. Here we only want to clip when applying the alpha option, not the resize:

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convert -density 300 -colorspace srgb image.eps -alpha transparent -clip -alpha opaque +clip -resize 1000x1000 -strip image.png

[fmw42]

Thanks. That command does seem to work fine in IM 7.0.6.6 and IM 7.0.6.7beta Q16 HDRI Mac OSX as

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magick -density 300 -colorspace srgb test1.eps -alpha transparent -clip -alpha opaque +clip -resize 1000x1000 -strip image.png

So the solution in IM 7 is turning off clipping before resizing. I take it that IM 6 does this automatically.