libvips/libvips/resample
John Cupitt ba0dea001d sort out premultiply rules for upsizing
vips_resize() uses vips_affine() for upsizing and vips_reduce() for
downsizing. Affine automaticaly does a vips_premultiply() for images
with an alpha channel, but reduce does not. This meant that we could
sometimes premultiply twice.

This patch adds a "premultiplied" flag for affine which turns automatic
premultiuplication off, vips_resize() uses this to block affine's auto
premul feature, and the resize docs are clarified to stress that the
operation does not do premultiplication for you.

See https://github.com/libvips/libvips/issues/1629
2020-05-19 14:31:34 +01:00
..
affine.c sort out premultiply rules for upsizing 2020-05-19 14:31:34 +01:00
bicubic.cpp more accurate bicubic of int16 images 2019-05-13 22:05:41 +01:00
dummy2.cc remove cimg and gmic 2014-10-08 17:51:07 +01:00
interpolate.c faster and more accurate bilinear 2019-05-14 13:10:45 +01:00
lbb.cpp fix mapim typo 2015-11-22 10:29:45 +00:00
Makefile.am compiles! 2016-11-02 09:29:19 +00:00
mapim.c more accurate bicubic of int16 images 2019-05-13 22:05:41 +01:00
nohalo.cpp fix nohalo, vsqbs interpolators 2016-03-24 16:06:31 +00:00
presample.h allow much larger reduce factors 2017-10-09 11:48:11 +01:00
quadratic.c Update GObject introspection annotations for libvips/resample directory 2017-09-30 17:26:55 +01:00
reduce.c doc fixups 2017-12-04 13:42:31 +00:00
reduceh.cpp revise kernel mask calculations 2020-05-10 18:45:27 +01:00
reducev.cpp doc fixups 2017-12-04 13:42:31 +00:00
resample.c revise doc comment for resample 2020-01-03 08:59:50 +00:00
resize.c sort out premultiply rules for upsizing 2020-05-19 14:31:34 +01:00
shrink.c Update GObject introspection annotations for libvips/resample directory 2017-09-30 17:26:55 +01:00
shrinkh.c "squash" to tiffsave now does lab as well 2019-12-18 17:29:34 +00:00
shrinkv.c free shrinkv resources earlier 2020-01-02 15:32:43 +00:00
similarity.c add vips_rotate() 2018-03-10 18:45:39 +00:00
templates.h revise kernel mask calculations 2020-05-10 18:45:27 +01:00
thumbnail.c add docs for option_string arg to thumbnail 2020-05-12 10:27:48 +01:00
transform.c Allow -DDEBUG build to compile 2017-12-06 22:04:11 +00:00
vsqbs.cpp fix nohalo, vsqbs interpolators 2016-03-24 16:06:31 +00:00