On 13.04.2018 at 06:58, Kalle Sommer Nielsen wrote: > 2018-04-05 14:04 GMT+02:00 Christoph M. Becker <cmbecke...@gmx.de>: > >> <https://bugs.php.net/73317> is still unresolved, and I'm not sure how >> to resolve it. >> >> TL;DR: the $threshold parameter of image2wbmp() is supposed to specify a >> *brightness threshold* for the required black and white conversion of >> the image. However, as of PHP 5.0.0 it is actually interpreted as the >> *foreground color*; all other colors are treated as background. This >> makes image2wbmp() basically identical to imagewbmp(). > > If thats the case that its basically identical, then a PHP_DEP_FE > should be sufficient for image2wbmp() and a removal in future version, > given its a rarely used function and migration is easy, even 7.4 could > potentially be fine for removal.
Thanks, Kalle! To clarify the behavioral problem: image2wbmp() is supposed to use _php_image_bw_convert() to do the conversion. However, that does not happen anymore since the commit[1] I've mentioned in the bug report. The problem is that the fallthrough to case PHP_GDIMG_TYPE_JPEG[2] had been intended (but not documented!), so that _php_image_bw_convert() (which is stored in func_p) would have been called, but now gdImageWBMP()[3] is called directly without converting to a black and white image according to the given threshold. It is quite interesting that it took apparently more than *ten* years until the bug has been reported[4]. This might be due to nobody using WBMP (see <https://bugs.php.net/76179>, though). Anyhow, I have to agree to the deprecation/removal suggestion, since: * fixing *this* 10y old bug is likely to cause more harm than good * a B/W conversion should be a *general* feature of GD (or likely rather libgd) * the B/W conversion[5] is very simplistic, and does not fit to gdImageGrayScale()'s[6] algorithm[7] I shall pursue the RFC process. [1] <http://git.php.net/?p=php-src.git;a=commit;h=cb5c9156c233a260e7a588141863720de82d2926> [2] <https://github.com/php/php-src/commit/cb5c9156c233a260e7a588141863720de82d2926#diff-bdf11f69d3dc3fb9601e59055a169449R1728> [3] <http://libgd.github.io/manuals/2.2.5/files/gd_wbmp-c.html#gdImageWBMP> [4] <https://bugs.php.net/73317> [5] <https://github.com/php/php-src/blob/PHP-7.2.4/ext/gd/gd.c#L4140> [6] <http://libgd.github.io/manuals/2.2.5/files/gd_filter-c.html#gdImageGrayScale> [7] <https://github.com/php/php-src/blob/PHP-7.2.4/ext/gd/libgd/gd_filter.c#L74> -- Christoph M. Becker -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
