possible bug converting ai to tiff IM 6.8.9.9 Q16 Mac OSX

[fmw42]

I am finding that flattening a transparent ai file while converting to tiff is leaving a perfectly opaque alpha channel rather then removing it.

Input:
https://app.box.com/s/icwny5lzebknx5rq3wxl

Command:

Code: Select all

convert FQ68DTFT_Fig2.ai -depth 8 -background white -flatten -compress lzw tmp1.tif

Workaround:

Code: Select all

convert FQ68DTFT_Fig2.ai -depth 8 -background white -flatten -compress lzw -alpha off tmp1.tif

or

Code: Select all

convert FQ68DTFT_Fig2.ai -alpha off -depth 8 -compress lzw tmp1.tif

[snibgo]

This can also happen from other operations, and writing to png instead of tiff. In general, output files can contain fully opaque alpha. It would be good if IM recognised when alpha was entirely opaque, and only wrote it for PNG32: or "-type *Alpha".