Collecting feeds via crontab every hour , these warning messages are being sent to me via mail.
Is there anyway to mute these libpng warnings but still receive the crontab mails , just-in-case there is a problem with the feed update process ?
libpng warning: iCCP: profile 'icc': 'RGB ': RGB color space not permitted on grayscale PNG
and
libpng warning: iCCP: known incorrect sRGB profile
Tiny Tiny RSS v17.12 (c30f5e1)
Debain 9.3 , PHP 5.6.30 , MariaDB 10.1.26
Thanks.
use something like update.php 2>/dev/null
other than that idk
I’m getting a similar error message repeatedly using the static docker setup. Is there a way to silence them there?
imagecreatefromstring(): gd-png: libpng warning: iCCP: known incorrect sRGB profile
1. include/colors.php(361): imagecreatefromstring(�PNG
nope, i think it’s just hardcoded to print this, and there’s no way to disable it.
I was looking for a solution to this, and to my best understanding those WARNINGs should not show up inside the tt-rss log.
In other projects, adding @ in front of the function call successfully suppressed the warning (but it is already there in the tt-rss code). For example here:
Related upstream commit from about a year ago:
As far as I can tell, the PHP/GD versions used by the tt-rss docker image should include this fix…so I am a bit at a loss.
I am also seeing other libpng warnings btw (but from the same function call):
imagecreatefromstring(): gd-png: libpng warning: cHRM: invalid chromaticities
1. include/colors.php(361): imagecreatefromstring(�PNG
i’m not sure if @ works with tt-rss internal logging, so this may not be (entirely?) on libpng. figuring this out would require quite a bit of digging and it just doesn’t feel like a high priority kinda thing.
as usual, i’d review a relevant PR 
Pull requested. 
I am not completely sure why the relevant part in include/errorhandler.php was commented…it seems fine (but I am also not an expert on this).
Interesting…so after the PR was merged, the WARNINGs still show up but look ‘nicer’? The second part containing the raw PNG data is missing now:
E_WARNING (2) include/colors.php:361 imagecreatefromstring(): gd-png: libpng warning: iCCP: known incorrect sRGB profile
12:01
E_WARNING (2) include/colors.php:361 imagecreatefromstring(): gd-png: libpng warning: cHRM: invalid chromaticities
12:00
I will continue investigating.
i suggest (again) using xdebug 