https://bugzilla.redhat.com/show_bug.cgi?id=2001332
Bug ID: 2001332 Summary: pango-view with --backend=ft2 and ---antialias=none generates antialiased renderings Product: Fedora Version: 34 Hardware: x86_64 OS: Linux Status: NEW Component: pango Severity: high Assignee: pwu@redhat.com Reporter: andre.maute@gmx.de QA Contact: extras-qa@fedoraproject.org CC: caillon+fedoraproject@gmail.com, fonts-bugs@lists.fedoraproject.org, gnome-sig@lists.fedoraproject.org, i18n-bugs@lists.fedoraproject.org, mclasen@redhat.com, pwu@redhat.com, rhughes@redhat.com, rstrode@redhat.com, sandmann@redhat.com, tagoh@redhat.com Target Milestone: --- Classification: Fedora
Created attachment 1820649 --> https://bugzilla.redhat.com/attachment.cgi?id=1820649&action=edit image showing the problem
Description of problem:
Hello Fedora Team,
I have a recently updated Fedora 34 installation.
The problem I want to report is that it looks like the pango-view tool is always turning antialiasing on when one uses the FreeType backend --backend=ft2, even when one explicitly switches antialiasing off with --antialias=none, whereas it works for the --backend=cairo option.
A second question would be if the FreeType backend generally doesn't/can't support --antialias=none? I tried to find some examples in C with antialising turned off but I wasn't successful.
I must confess I didn't check other distributions.
As pango-view is regarded as a tool for creating minimal reproducers against the font rendering stack, I dare to set the severity to 'high' :-)
Best Regards Andre
Version-Release number of selected component (if applicable):
$ uname -a Linux localhost.localdomain 5.13.13-200.fc34.x86_64 #1 SMP Thu Aug 26 17:06:39 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux
$ dnf list installed | grep dejavu dejavu-lgc-sans-fonts.noarch 2.37-16.fc34 @fedora dejavu-lgc-sans-mono-fonts.noarch 2.37-16.fc34 @fedora dejavu-lgc-serif-fonts.noarch 2.37-16.fc34 @fedora dejavu-sans-fonts.noarch 2.37-16.fc34 @fedora dejavu-sans-mono-fonts.noarch 2.37-16.fc34 @fedora dejavu-serif-fonts.noarch 2.37-16.fc34 @fedora
$ dnf list installed | grep ImageMagick ImageMagick.x86_64 1:6.9.11.27-3.fc34 @fedora ImageMagick-libs.x86_64 1:6.9.11.27-3.fc34 @fedora
$ dnf list installed | grep pango pango.i686 1.48.9-2.fc34 @updates pango.x86_64 1.48.9-2.fc34 @updates pango-devel.x86_64 1.48.9-2.fc34 @updates pangomm.x86_64 2.46.1-1.fc34 @updates
$ dnf list installed | grep freetype freetype.i686 2.10.4-3.fc34 @fedora freetype.x86_64 2.10.4-3.fc34 @fedora freetype-devel.x86_64 2.10.4-3.fc34 @fedora
$ dnf list installed | grep fontconfig fontconfig.i686 2.13.94-2.fc34 @updates fontconfig.x86_64 2.13.94-2.fc34 @updates fontconfig-devel.x86_64 2.13.94-2.fc34 @updates
$ dnf list installed | grep cairo cairo.i686 1.17.4-3.fc34 @fedora cairo.x86_64 1.17.4-3.fc34 @fedora cairo-devel.x86_64 1.17.4-3.fc34 @fedora cairo-gobject.i686 1.17.4-3.fc34 @fedora cairo-gobject.x86_64 1.17.4-3.fc34 @fedora cairomm.x86_64 1.14.2-8.fc34 @fedora python2-cairo.x86_64 1.18.2-8.fc34 @fedora python3-cairo.x86_64 1.20.0-2.fc34 @fedora
How reproducible:
Always
Steps to Reproduce:
$ pango-view --no-display --dpi=72 --backend=cairo --antialias=none --font="DejaVu Sans 38" --text="ABCDEFGHIJKLMNOPQRSTUVWXYZ" --output=abc-cairo-aa-none.png $ pango-view --no-display --dpi=72 --backend=cairo --antialias=gray --font="DejaVu Sans 38" --text="ABCDEFGHIJKLMNOPQRSTUVWXYZ" --output=abc-cairo-aa-gray.png $ pango-view --no-display --dpi=72 --backend=cairo --antialias=subpixel --font="DejaVu Sans 38" --text="ABCDEFGHIJKLMNOPQRSTUVWXYZ" --output=abc-cairo-aa-subpixel.png $ pango-view --no-display --dpi=72 --backend=ft2 --antialias=none --font="DejaVu Sans 38" --text="ABCDEFGHIJKLMNOPQRSTUVWXYZ" --output=abc-ft2-aa-none.png $ pango-view --no-display --dpi=72 --backend=ft2 --antialias=gray --font="DejaVu Sans 38" --text="ABCDEFGHIJKLMNOPQRSTUVWXYZ" --output=abc-ft2-aa-gray.png $ pango-view --no-display --dpi=72 --backend=ft2 --antialias=subpixel --font="DejaVu Sans 38" --text="ABCDEFGHIJKLMNOPQRSTUVWXYZ" --output=abc-ft2-aa-subpixel.png
$ gimp abc-*.png
Actual results: Attached pngs. The file abc-ft2-aa-none.png is in gray-scale and not as expected in black-white. The file abc-cairo-aa-none.png is in black-white as expected.
Expected results: I would have expected the files abc*--aa-none.png looking near identical.
Additional info: