Package: imagemagick Version: 8:6.9.10.14+dfsg-4 Severity: important Hi,
'convert' delegates conversion to webp format to the 'cwebp' utility. (possibly due to #806425, as there seem to also be native support in coders/webp.c) However the tool is invoked incorrectly. 1) "-quiet" is used instead of "-q", hence quality is ignored www/source/delegates.xml: <delegate decode="png" encode="webp" command=""cwebp" -quiet %Q "%i" -o "%o""/> 2) lossless parameter is not taken into account, resulting in LOSSY encoding even when stating the opposite: $ convert -verbose large.png -quality 100 -define webp:lossless=true large.webp 'cwebp' -quiet 100 '/tmp/magick-17343sNKIc5bM2Kkg' -o '/tmp/magick-173430j5VYMgDbQcg' $ webpinfo large.webp Format: Lossy (1) Valid command line would be: $ cwebp -lossless large.png -o large.webp $ webpinfo large.webp Format: Lossless (2) Using another source format (such as bmp or ppm) results in an intermediate automatic conversion to .png, hence does not avoid the bug. Setting severity as "important" because there is silent loss of information. Cheers! Sylvain
